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DEFRA PROJECT WU0132: SUSTAINABLE WATER FOR LIVESTOCK
APPENDICES 1-4
APPENDIX 1. Water requirements for drinking and servicing of livestock This task reviews published livestock information on livestock drinking and washing water
requirements based upon species, production system, herd behaviour, and body weight.
Evidence has been obtained by examining previous Defra research (e.g. WU0101, WU0102,
WU0123), journal publications and agricultural best practice documents e.g. Waterwise on
the Farm (Environment Agency 2007). This particular document provides information on
process and cleaning water daily volumes, taking into account housing periods. Additional
information on actual practical performance of sustainable water management systems has
been derived from consultancy water audits undertaken by ADAS in the Eden Valley
(ADAS, 2007).
Tables of water use by livestock sector and type, summarised by requirement and on a per day
and yearly basis are shown below.
1. Cattle
Table A1.1
Drinking
water
requirement
(L day-1)
Drinking
water
requirement
(L year-1)
Cleaning water
requirement
(L day-1)
Cleaning water
requirement
(L year-1)
Total water
requirement
(L day-1)
Total water
requirement
(L year-1)
Source Animal
Non-
power
hose
power
hose
non-
power
hose
power
hose
1 Dairy cattle 45-70
16,425 -
25,550
14 -
22 27-45
5,110 -
8,030
9855 -
16425 59 - 92
26,280 -
41,975
Calves 15-25 5,475 - 9,125 - - - - 15 - 25 5,475 - 9,125
Beef cows 25-45
9,125 -
16,425 - - - - 25 - 45
9,125 -
16,425
2 Dairy cattle - -
13 -
30 17 - 40
4,745 -
10,950
6,205
-
14,600 - -
3 Dairy cattle - - 18 35 6,570 12,775 - -
4
Dairy cow –
lactating 104.5 32,421 - - - - - -
Dairy cow -
dry period 20 1095 - - - - - -
Dairy cow –
overall 91.8 33,516 - - - - - -
Beef cows 20 7300 - - - - 20 7300
Dairy &
beef bull 20 7300 - - - - 20 7300
Calves 5 1825 - - - - 5 1825
5 Dairy cattle 91.8 33,516 25 - 9,125* - 116.8 42641
Growers &
replacements 20 7300 - - - - 20 7300
Beef cows &
heifers 20 7300 - - - - 20 7300
Dairy &
beef bulls 20 7300 - - - - 20 7300
Beef store 20 7300 - - - - 20 7300
2
cattle
Dairy &
beef calves 5 1825 - - - - 5 1825
6 Dairy cattle 53.9 - 64.8
19,658 -
23,635
19.28
- 20.3 -
2,190 -
7,409 - 59.9 - 85.1
21,848 -
31,044
7 Dairy cow 75 27,375 - - - - 75 27,375
Dry cattle & Beef 50 18,250 - - - - 50 18,250
Sources
1. Environment Agency (2003)
2. King et al (2006)
3. Water code (Anon, 1998)
4. Cottrill (2006)
5. Environment Agency (2007)
6. Dairy Co (2009)
7. Whiteley (2001)
Table A1.2
Animal Age/condition
water requirement (L animal -1
day -1)
Holstein calves 1 month 5.9 - 9.1
Holstein calves 2 month 6.8 - 10.9
Holstein calves 3 month 9.6 - 12.7
Holstein calves 4 month 13.7 - 15.9
Holstein calves 5 month 17.3 - 20.9
Holstein heifers 15-18 months 26.8 - 32.3
Holstein heifers 18-24 months 33.2 - 43.7
Jersey cows 13.5 kg milk/day 59.2 - 70.5
Guernsey cows 13.5 kg milk/day 62.8 - 72.8
Ayrshire, Brown Swiss, Holstein cows 13.5 kg milk/day 66.0 - 77.4
Ayrshire, Brown Swiss, Holstein cows 22.5 kg milk/day 109.2 - 122.9
Dry cows Pregnant 6-9 months 41.0 - 59.2
Source: Lardy et al (2008)
Table A1.3 Combined data
Animal
Drinking
water
requirement
(L day-1)
Drinking
water
requirement
(L year-1)
Cleaning
water
requirement
(L day-1)
Cleaning
water
requirement
(L year-1)
Total water
requirement
(L day-1)
Total water
requirement
(L year-1)
Dairy cow
lactating 104.5 32,421 13 - 45
4,745 -
15,075 117.5 - 149.5
37,166 -
47,496
Dairy cow -
dry period 20 1,200 - - 20 1,200
Beef cows
& heifers 20-50
7,300 -
18,250 - - 20-50 7,300 - 18,250
Dairy &
beef bulls 20-50
7,300 -
18,250 - - 20-50 7,300 - 18,250
Dairy &
beefs calves 5-25 900 - 4,500 - - 5-25 900 - 4,500
Data in Table A1.1 represents both the daily and annual intake and wash water requirements
of cattle taken from various sources as highlighted. Table A1.2 shows drinking water intake
for various cattle breeds at different stages of the lifecycle. In Table A1.3 which combines
data from the sources reviewed to produce ranges of drinking water intake/wash water
requirements, data from Table A1.2 are not used, as the figures relate to intake requirement as
a function of air temperature and are not comparable with other data representing UK cattle.
3
Annual water requirements for dairy cattle are based on a 305 day period for lactating cows
and a 60 day period for dry cows. Annual requirements for dairy and beef bulls are based on a
6 month period however the annual requirement of all other categories is based on 365 day
periods. Data concerning wash water requirements is only provided for lactating dairy cows which will visit the parlour on a daily basis for milking.
1.2 Sheep
Table A1.4
Animal System
Drinking water
requirement
(L day-1)
Drinking water
requirement
(L year-1)
Sheep Drinking 2.5 - 5.0 912.5 - 1825
Sheep Dipping (per dip) 2.5 5
Source: Environment Agency (2003)
Table A1.5
Animal
Drinking water
requirement
(L day-1)
Non-pregnant lowland ewes 3.3
Ewes in early pregnancy 4.2
Ewes in mid pregnancy 5.2
Ewes in late pregnancy 7
Ewes in early lactation 7.3
Source: King et al (2006) & Consultancy experience - Kate Phillips
Table A1.6
Animal
Drinking water
requirement
(L day-1)
Ewe 4.5
Lambs (general) 2
Lambs finished early (October) 1.4
Lambs finished late (Feburary) 3.3
Source: King et al (2006)
Table A1.7
Animal
Drinking water
requirement
(L day-1)
Dipping
(L event-1)
Drinking water
requirement
(L year-1)
Dipping
(L yr-1)
Ewes 4.5 2.25 1644.3 4.5
Rams & other
adult sheep 3.3 2.25 1204.5 4.5
Lambs under 1 yr 1.68 2.25 613.5 0.9
Source: Environment Agency (2007)
Table A1.8
Animal
Drinking
water
requirement
(L day-1)
Drinking
water
requirement
(L year-1)
Dipping
(L event-1)
Dipping
(L year-1)
Total water
requirement
volume
(L year-1)
Non-pregnant lowland ewes 3.3 604 2.5 0.75 605
Ewes in early pregnancy 4.2 256 - - 252
4
Ewes in mid pregnancy 5.2 161 - - 156
Ewes in late pregnancy 7 413 - - 420
Ewes in early lactation 7.3 153 - - 153
Lambs finished early
(October) 2 360 2.5 0.75 361
Lambs finished late
(Feburary) 3.3 990 2.5 0.75 991
Rams & other adult sheep 3.3 1,205 2.5 0.75 1,205
Tables A1.4-A1.8 display data for the drinking water intake requirement gathered from various sources as highlighted, and in the case of A1.4 and A1.8 includes the water
requirement concerned with dipping events. These data are combined in Table A1.8 along
with consultancy experience to provide a combined insight into the water requirements of sheep at various stages of life cycle.
Annual intake requirements are based on the following assumptions.
• Non-pregnant lowland ewes: intake based on 6 months of water intake at 3.3l per day.
• Ewes in early pregnancy: intake based on 2 months of water intake at 4.2l per day.
• Ewes in mid pregnancy: intake based on 1 month of water intake at 5.2l per day.
• Ewes in late pregnancy: intake based on 2 months of water intake at 7l per day.
• Ewes in early lactation: based on 1 month of water intake at 7.3l per day.
• Lambs finished early (October): intake based on 6 months of water intake at 2.0l per day.
• Lambs finished late (February): intake based 10 months of intake at 3.3l per day.
Figures relating to water requirements of sheep dipping events only consider non – pregnant
lowland ewes, lambs and rams & other adult sheep. For these categories the annual volume of
water associated with dipping is calculated as one dipping event per year at 30% of the
volume required to dip a sheep as approximately only 30% of the national flock are dipped.
1.3 Pigs
Table A1.9
Animal System
Water volume
(L day-1 per animal)
Cleaning after each batch (10 pigs/pen) 16-24
Lactating sows Drinking 15-30
Pregnant sows & boars Drinking 9-14
Weaners Drinking 5
Source: Environment Agency (2003)
Table A1.10 Drinking water requirement (litres pig
-1 day
-1)
Animal Consultancy estimates Research estimates
Dry sows & gilts 8-10 10
Farrowing sows 30 21
Weaners 2 1.6
Growers 4 3.4
Finishers 5.5 5.7
Source: Consultancy estimates Mike Brade (ADAS), Research estimates (Smith et al, 2000), overall King et al (2006)
5
Table A1.11
Animal
Weeks
per
cycle Places
Number
of pens
Clean
time
(mins)
Batches
per
year
Occupancy
%
Total
wash
time
(mins
)
Annual
water
vol (L)
Wash
water
(L/batch)
Water use
(L/pig/wk)
Dry sows
& gilts 52 310 100 720 9821 0.6
Farrowing
sows 5 90 90 15 10 96 13500 184113 204.6 39.4
Weaners 4 650 43 10 12 90 4983 67963 136.4 2
Growers 5 810 54 15 10 96 8100 110468 204.6 2.6
Cutters 8 1296 86 18 6 95 9331 127259 245.5 1.9
Finishers 11 1782 119 20 5 95 10692 145818 272.8 1.6
Source: King et al (2006)
Table A1.12
Animal
Production
cycle
(weeks)
Drinking
water
requirement
(L day-1)
Wash water
(L day-1)
Drinking water
requirement
(L year-1)
Wash water
(L year-1)
Dry sows & gilts 52 6 - 1708.2 -
Boars 52 6 - 2190 -
Farrowing sows 5 30 5.63 2409 452.1
Maiden gilts 10 5.5 - 2007.5 -
Barren sows 10 5.5 - 2007.5 -
Weaners (20kg) 4 2 0.286 730 104.4
Growers (50kg) 5 4 0.371 1460 135.4
Finishing pigs 11 5.5 - 2007.5 -
Source: Environment Agency (2007)
Table A1.13
Animal
Drinking water requirement
(L animal-1 day-1)
Lower range drinking
water requirement
(L year-1)
Higher range drinking
water requirement
(L year-1)
Dry sows &
gilts 6-10 2190 3650
Pregnant sows 9-14 2381 3703
Farrowing sows 15-30 1208 2415
Maiden gilts 5.5 2008
Barren sows 5.5 2008
Weaners (20kg) 1.6 -2.0 584 730
Growers (50kg) 3.4-5.0 1241 1825
Finishers 5.5 - 5.7 2008 2081
Boars 6-14 2190 5110
Table 1.14
Animal Production cycle (weeks)
Wash water
(L day-1)
Wash water
(L year-1)
Dry sows &
gilts 52 - -
Boars 52 - -
Farrowing sows 5 5.63 452.1
6
Maiden gilts 10 - -
Barren sows 10 - -
Weaners
(,20kg) 4 0.286 104.4
Growers (50kg) 5 0.371 135.4
Finishing pigs 11 - -
For Tables A1.13 and A1.1.4, annual intake requirements are based on the following
assumptions.
• Dry sows & gilts: annual water intake based on 365 day period
• Pregnant sows: annual water intake based on 2.3 pregnancies per year each 115 days.
• Farrowing sows: annual water consumption based on 2.3 farrowing periods, each 5 weeks.
• Maiden gilts & barren sows: annual intake based on 365 day period.
• Weaners: annual intake based on 365 day period.
• Growers: annual intake based on 365 day period.
• Finishers: annual intake based on 365 day period.
• Boars: annual intake based on 365 day period.
1.4 Poultry
Table A1.15
Species
Cycle length
(including clean
out)
Drinking water
(L bird-1)
Stocking density
(birds m-2 floor
area)
Replacement pullets (for
commercial egg production) 19 weeks
10.2 (age 1-16
weeks) 12
Laying hens - cage egg
production 58 weeks
80 (age 16-72
weeks) 22
laying hens - non cage egg
production 58 weeks
87 (age 16-72
weeks) 11.5
Broilers 56 days 10 (age 1-49 days) 12
Broiler breeders 46 weeks
60 (age 20-64
weeks) 6
Ducks 63 days 60 (age 1 -49 days 7
Turkeys (male) 22 weeks
100 (age 1-20
weeks) 2.2
Turkeys (female) 18 weeks
50 (age 1-16
weeks) 4.3
Table A1.16
Animal
Production
cycle (weeks)
Drinking
Water
(L day-1)
Wash water
(L m-2 floor
area)
Standard
density
(birds m-2)
Drinking
water
(L year-1)
Wash
water
(L year-1)
Pullet 16.00 0.09 5.00 12.00 33.24 1.14
Broiler 7.00 0.20 5.00 12.00 74.49 2.71
Laying hen –
caged 56.00 0.20 6.00 22.00 74.49 0.24
Laying hen - non
caged 56.00 0.22 6.00 11.50 81.01 0.47
Broiler & layer 44.00 0.19 5.00 6.00 71.10 0.94
7
breeder & cock
Duck 7.00 1.22 5.00 7.00 446.94 4.13
Turkey (male) 20.00 0.71 5.00 2.20 260.71 5.37
Turkey (female) 16.00 0.45 5.00 4.30 162.95 3.36
References
Environment Agency (2003) Optimum Use of Water for Industry and Agriculture: Best Practice
Manual.
King et al (2006) Water use in Agriculture: Establishing a Baseline, Report for Defra Project WU0102
Water code (Anon, 1998), Code of Agricultural Practice for the protection of water. MAFF
Publications PB0585
Cottrill (2006) – Figures taken from King et al (2006) originally derived from ADAS personal
communication.
Environment Agency (2007) Waterwise on the Farm,
Dairy Co (2009) Effective Use of Water on Dairy Farms.
Whiteley (2001) The Ensus Farming Club Water Saving Visits, Review of the Water Saving visits.
8
APPENDIX 2. Hygiene and legal issues associated with alternative sources of
water supply to livestock
2.1 Overview
Rainwater harvesting has been practised in arid or semi-arid climates for many centuries for
human drinking and other uses, but only recently have there been published studies on the
microbiological and chemical contamination of rainwater, and the effects of local atmospheric conditions and sources of airborne contamination.
Rainwater is relatively free from impurities except those picked up by rain from the
atmosphere, but the quality of rainwater may deteriorate during harvesting, storage and use.
Wind-blown dirt, leaves, faecal droppings from birds and animals, insects and other debris on
the catchment areas can be sources of contamination of rainwater, leading to health risks for
livestock. However, risks from these hazards can be minimized by good design and
maintenance.
Water is an essential nutrient which is involved in all basic physiological functions of the
body. However, it is important to note that water, relative to other nutrients, is consumed in
considerably larger quantities. Therefore, water availability and quality are extremely important for animal health and productivity. Considering that water is consumed in such
large quantities, if water is of poor quality, there is an increased risk that water contaminants
could reach a level that may be harmful to the animal and may cause disease or leave residues
harmful to those consuming products of animal origin.
Rainwater also lacks minerals, and some, such as calcium, magnesium, iron and fluoride, are
considered essential for health. Although most essential nutrients are derived from an
animal’s diet, the lack of minerals, especially calcium and magnesium, should be considered
if rainwater is the only source of water available to livestock.
Rainwater is generally slightly acidic and low in dissolved minerals; and as a result it is
relatively aggressive. Rainwater can therefore dissolve heavy metals and other impurities
from materials of the catchment and storage tank. In most cases, chemical concentrations in
rainwater which has been analysed have been shown to be within acceptable limits. However,
elevated levels of zinc and lead have been reported in samples of stored rainwater, and this
could be from leaching from metallic roofs and storage tanks or possibly from atmospheric
pollution.
There have been many studies on the potential impact of high levels of certain chemicals on livestock health but the literature search has revealed no widespread incidents of harm to
livestock from drinking rainwater.
Microbial contamination of collected rainwater indicated by coliforms or E. coli is quite
common, particularly in samples collected shortly after rainfall. Pathogens such as
Cryptosporidium, Giardia, Campylobacter, Vibrio, Salmonella, Shigella and Pseudomonas
have also been detected in rainwater. However, the occurrence of pathogens is generally
lower in rainwater than in unprotected surface waters, and the presence of non-bacterial
pathogens, in particular, can be minimized.
Higher microbial concentrations are generally found in the first flush of rainwater, and the
level of contamination reduces as the rain continues. However there have been no documented livestock disease outbreaks attributed to contaminated rainwater, although some
studies showed reduced consumption, and hence effects on productivity, thought to be caused
by bad odour or taste. A system is therefore recommended to divert the contaminated first
9
flow of rainwater from roof surfaces. Some manual and automatic devices are available to
divert the first flush of rainwater.
There are no specific legal requirements concerning quality of livestock drinking water.
Since 1 January 2006 the hygiene of food production throughout the EU has been covered by EC Regulation 852/2004 on the hygiene of foodstuffs. This regulation does not make specific
reference to livestock drinking water. Annex I concerns primary production and includes a
requirement for animal keepers “to use potable water, or clean water, whenever necessary to prevent contamination”. Clean water is defined in the regulations as “water that does not
contain micro-organisms or harmful substances in quantities capable of directly or indirectly
affecting the health quality of food.” This was interpreted by FSA to mean that livestock
drinking water should be protected from contamination and keepers should not knowingly
permit animals to drink from a contaminated source.
There are no published UK standards setting out the microbiological or chemical quality of
water to be used for livestock drinking although standards have been published in other
countries such as Canada, USA, and jointly by Australia and New Zealand.
2.2 Background
Rainwater harvesting has been practised in arid or semi-arid climates for many centuries
(Abdel Khaleq and Alhaj Ahmed, 2007) for human drinking and other uses, but only recently
have there been published studies on the microbiological and chemical contamination of
rainwater, and the effects of local atmospheric conditions and sources of airborne
contamination.
Rainwater is relatively free from impurities except those picked up by rain from the atmosphere, but the quality of rainwater may deteriorate during harvesting, storage and use.
Wind-blown dirt, leaves, faecal droppings from birds and animals, insects and other debris on
the catchment areas can be sources of contamination of rainwater, leading to health risks for livestock. However, risks from these hazards can be minimized by good design and
maintenance.
Water is an essential nutrient which is involved in all basic physiological functions of the
body. However, it is important to note that water, relative to other nutrients, is consumed in
considerably larger quantities. Therefore, water availability and quality are extremely
important for animal health and productivity. Considering that water is consumed in such
large quantities, if water is of poor quality, there is an increased risk that water contaminants
could reach a level that may be harmful to the animal and may cause disease or leave residues
harmful to those consuming products of animal origin.
2.3 Studies on rainwater quality
There are few detailed published reports of microbiological and chemical tests carried out on
rainwater and most have been concerned with quality of water for human use. The majority of the studies have been reported from countries such as Australia, New Zealand and Canada
where rainwater harvesting has been practiced on a wide scale.
2.3.1 Microbiological contamination
Higher microbial concentrations are generally found in the first flush of rainwater, and the
level of contamination reduces as the rain continues. A system is therefore necessary to divert
the contaminated first flow of rainwater from roof surfaces. Some manual and automatic
devices are available to divert the first flush of rainwater; to quote Stan Abbott “spectacular
10
improvements in the water quality in the rain tanks are attributed to first flush diverters”
(Abbott, 2008).
Microbial quality of drinking water is commonly measured by testing for Escherichia coli (E.
coli), or alternatively thermo-tolerant coliforms (sometimes referred to as faecal coliforms), as indicators of faecal contamination and hence the possible presence of enteric pathogens.
Thermotolerant coliforms or E. coli have been commonly identified in domestic tanks (Fuller et al. 1981; Dillaha & Zolan 1985; Fujioka & Chin 1987; Haeber & Waller 1987;
Wirojanagud 1987; Gee 1993; Edwards 1994; Thurman 1995; Simmons et al. 2001). This
implies that enteric pathogens could often be present in rainwater tanks. However, when
surveys have included testing for specific pathogens, detection has not been common.
In Australia, Campylobacter was identified in six of 47 tanks in one survey whereas other
pathogens, such as Salmonella, Shigella, Cryptosporidium and Giardia, were not detected in a
number of surveys of domestic rainwater tanks (Fuller et al. 1981; Thurman 1995; Victorian
Department of Natural Resources and Environment 1997).
In New Zealand, Campylobacter was identified in nine of 24 tanks, but the maximum concentrations were less than one per 100 ml and it was concluded that the risk of illness to
humans from drinking this water was low (Savill et al. 2001). A second New Zealand survey
found faecal coliforms in 70 of 125 rainwater tanks but Salmonella was only detected in one
tank. Cryptosporidium oocysts of unknown species were detected in two of 50 tanks that
contained at least 30 faecal coliforms or 60 enterococci per 100 ml (Simmons et al. 2001).
Campylobacter or Giardia was not detected in any tanks. Similarly Wirojanagud (1987)
reported the detection of faecal coliforms in 43 of 156 samples from rainwater tanks in
Thailand, but Salmonella was only detected in one sample and Shigella in none. An
exception to this trend was the detection of Cryptosporidium and Giardia in 400 litre samples, collected from a large number of rainwater cisterns in the Virgin Islands, where installation of
rainwater storage is compulsory due to a lack of fresh water resources (Crabtree et al. 1996).
The relatively frequent detection of faecal indicator bacteria is not surprising, given that roof
catchments and guttering are subject to contamination by bird and small animal droppings.
However, despite the prevalence of indicator organisms, reports of illness associated with rainwater tanks are relatively rare. Although traditional under-reporting of gastrointestinal
illness will have contributed to a lack of evidence, epidemiological investigations undertaken
in South Australia also failed to identify any link (Heyworth et al. 1999; Heyworth 2001).
There have been a few reports of human illness associated with Campylobacter and
Salmonella in rainwater tanks. In four of these reports the contaminating organisms were
detected in both those infected and their rainwater sources (Koplan et al. 1978; Brodribb et al.
1995; Simmons & Smith 1997; Taylor et al. 2000). Brodribb et al. (1995) reported an
investigation into recurrent infections by Campylobacter foetus, of an elderly immunocompromised woman where the organism was also isolated from the patient’s
rainwater tank, which served as her sole source of drinking water. No further infections
occurred after the patient started boiling the water before consumption.
It was postulated that an outbreak of 23 cases of campylobacteriosis at a Queensland island
resort was probably associated with contamination of rainwater tanks, even though
Campylobacter was not isolated from rainwater samples (Merritt et al. 1999). A study of risk
factors for campylobacteriosis in New Zealand associated consumption of rainwater as a
source of increased risk in a small number of cases (23 cases, 11 controls; odds ratio 2.2)
(Eberhart-Phillips et al. 1997).
An investigation of an outbreak of Salmonella infections in a church group in Trinidad,
Jamaica led to detection of the organism in rainwater samples and in food prepared using the
11
rainwater (Koplan et al. 1978). It was reported that the roof catchment was covered with
dried and fresh bird droppings.
Similarly, Salmonella was isolated from a rainwater tank used by a family of four in New
Zealand that had suffered from recurrent infections by the same organism (Simmons & Smith 1997). In an investigation of 28 cases of gastroenteritis among 200 workers at a construction
site in Queensland, Salmonella Saintpaul was isolated from both cases and rainwater samples
(Taylor et al. 2000). Animal access was suggested as being the source of contamination with several live frogs being found in one of the suspect tanks.
An underground rainwater tank was associated with a waterborne outbreak of
cryptosporidiosis / giardiasis in Australia (Lester 1992). Eighty-nine people supplied with
drinking water from the tank became ill. Investigations revealed the tank had been
contaminated by an overflow from a septic tank and therefore it was not connected with the
original source of the water.
One explanation for the apparent disparity in frequency of faecal contamination and the
prevalence of human illness could be the likely source of contamination. For most rainwater tanks, particularly those installed above-ground, faecal contamination is limited to small
animals and birds. While faecal contamination from these sources can include enteric
pathogens, there is a degree of host group pathogen specificity. Enteric viruses are the most
specific; in general, human infectious species only infect humans and animal (non-human)
infectious species only infect animals.
The host range for protozoa is a little broader, but except for the severely
immunocompromised, human infections with Cryptosporidium are predominantly associated
with genotypes of C. parvum carried by humans and livestock (McLauchlin et al. 2000; Chappell & Okhuysen 2002). The livestock genotype can be transmitted to some other
animals, but the human genotype is very specific for humans (McLauchlin et al. 2000;
Morgan-Ryan et al. 2002). C. meleagridis carried by birds has been associated with low numbers of human cases (McLauchlin et al. 2000; Pedraza-Diaz et al. 2001).
Bacterial pathogens are the least specific and birds, for example, are known to carry and excrete potentially human infectious Campylobacter (Koenrad et al. 1997; Whelan et al.
1983). Birds that live in close proximity to human populations can also transport Salmonella
(Hernandez et al. 2003; Refsum et al. 2002).
These limitations are important, as enteric human illness mediated by waterborne bacteria
requires ingestion of much higher numbers of organisms than enteric illness mediated by
protozoa or viruses. Dosing studies have found that while ingestion of between one and 10
virus particles or protozoan cysts can lead to infection, at least 1000 and often more than 100
000 bacteria are required (Haas 1983; Regli et al. 1991; Gerba et al. 1996; Okhuysen et al. 1999). It is considered likely that most healthy animals are tolerant of somewhat higher levels
of contamination, although young animals are likely to be more susceptible.
2.3.2 Chemical contamination
There may be localised areas where tank rainwater quality is affected by specific industries.
Relatively high concentrations of lead (mean 61 µg/l) were detected in surveys of tank
rainwater collected in Port Pirie, South Australia (Fuller et al. 1981; Body 1986). The source
of this contamination was considered to be a very large smelter, and Port Pirie residents were
advised not to use rainwater collected in domestic tanks for drinking or food preparation.
Use of pesticides and potential drift from agricultural areas has been the subject of increasing
public concern, and one of the issues commonly raised has been potential contamination of
12
roofs used as catchments for rainwater tanks. In surveys of rainwater quality in rural areas,
most samples did not contain detectable concentrations of pesticides (Victorian Department of
Natural Resources and Environment 1997; Fuller et al. 1981; Paskevich 1992; New South
Wales Environment Protection Authority and Northern Districts Public Health Unit 1996).
Endosulfan, profenofos, chlorpyrifos and dieldrin were detected in some samples, but all at concentrations well below health-related guideline values.
Lead flashing has been suggested as a possible source of contamination of collected rainwater but there is little supporting evidence. Leaching of lead into roof run-off may be more of a
problem from poorly maintained roofs and gutters, where the process could be increased by
the action of water made acidic with organic substances from materials such as leaf litter.
The contribution of building and tank materials to lead in collected water has been examined.
Concentrations of lead associated with using galvanised iron in roof or tank construction were
acceptable in two surveys (Victorian Department of Natural Resources and Environment
1997; Fuller et al. 1981). In a third survey, Simmons et al. (2001) reported that individually,
use of lead solder, lead flashing or galvanised iron in roof catchments was not associated with
increased concentrations of lead in tank water. However, increased concentrations of lead were reported when combined data on water collected from catchment areas with lead or
galvanised iron in the roof, guttering or spouting were analysed. The lead concentrations
detected in the survey were low to moderate and in most cases did not appear to be a major
issue, with a 95th percentile of 2 µg/l and a maximum of 14 µg/l compared to the Australian
drinking water guidelines value of 10 µg/l.
Preservative-treated wood could be a source of chemical contamination if there is direct
contact with rainwater to be collected in a storage tank. Examples of timber preservatives
include:
• water-based preservatives, such as copper chrome arsenates and boron compounds
• oil-type or oil-based preservatives, such as creosote
• light organic solvent preservatives, such as solutions containing pentachlorophenol.
Although no longer used, asbestos may be present on the roofs of older buildings. Although
asbestos fibres are dangerous to health when inhaled, it is not believed that asbestos in
drinking water poses a risk. Asbestos roofing material should, as far as is practicable, be left
undisturbed since fibres can be released into the air by actions such as cutting, grinding or
drilling. High-pressure roof cleaning methods should also be avoided. Where the roof catchment area has deteriorated badly, it should be replaced with asbestos-free substitutes.
Before purchasing materials or paint for roofs used to collect rainwater, read and observe the
manufacturer’s recommendations on labels and brochures. Look for warnings. If in doubt,
check with the manufacturer. The three types of paints and coatings of concern are:
• lead-based paints (including primers) – concentrations of lead in paints have been
substantially reduced in recent years, but care should still be taken to ensure that paints
used are suitable for use in association with collecting rainwater for drinking
• acrylic paint – will leach dissolved chemicals, including detergents, in the first few run-
offs after application and these run-offs should not be collected
• bitumen-based (tar) materials – are generally not recommended, as they may leach
hazardous substances or cause taste problems.
Rainwater tanks are available in a range of suitable materials including galvanised steel,
fibreglass, plastic and concrete. All can be suitable, providing the materials comply with the
requirements of regulations detailing products for use in contact with drinking water, i.e.
Regulation 31 of the Water Supply (Water Quality) Regulations 2000. The list of approved products is updated annually by the Drinking Water Inspectorate (DWI, 2011). New
13
rainwater tanks can impart specific tastes and odours. For example, galvanised tanks can
impart a metallic taste when first filled, due to leaching of excess zinc.
New concrete tanks can release excess lime, leading to a high pH (Gee 1993; Simmons et al.
2001) and possibly a bitter taste. Rainwater from other types of tanks tends to be slightly acidic (Simmons et al. 2001). Although results outside the recommended pH range of 6.5–8.5
have been recorded, they are unlikely to have a direct health impact, but low pH in particular
could cause increased corrosion and result in dissolution of metal tanks, pipes and fittings.
2.3.3 Tastes and odours
Poor tasting water can inhibit sufficient intake of water by livestock and thereby affect their
productivity and health. The absence of distinctive tastes and odours is a feature of good
quality rainwater, but there is a range of factors and/or conditions that can cause deterioration
of these characteristics during collection, storage and piping. The principal sources of taste
and odour are:
• dead animals or birds contaminating the water
• sediments and slimes at the bottom of tanks or in pipework that can hold stagnant water
• soil and decaying vegetation allowed to accumulate in guttering
• algal growth in pipework or open tanks
• pollen.
Odours from sediments and slimes are the most commonly reported. Sediment can
accumulate in the bottom of tanks that have not been cleaned frequently enough. In warm to
hot weather, anaerobic conditions can develop, leading to growth of microorganisms that
produce sulphides, with a distinctive sewage or rotten egg-like smell.
Pipework that does not completely self drain (for example, u-bends or underground piping
from roof catchments to tanks, between tanks or from tanks to buildings) can also be a source
of off-tastes and odours, particularly where stagnant water can develop and be retained between rain events. In these environments, slimes and biofilms can be formed and in the
same manner as for tank sediments, anaerobic growth can occur, again leading to production
of sulphides.
Decaying vegetation and soils accumulated in guttering can also release taste and odour
compounds into water, particularly if the gutters are not kept clean and do not fully drain
between rain events.
Open tanks are fairly uncommon but exposure of stored rainwater to light will lead to algal
growth. Most algae are not a health risk, but growth can adversely affect the taste, odour and
appearance of rainwater. Piping that is not impervious to light can also support algal growth.
Some pollens have very distinctive tastes and odours and if allowed to accumulate on roof
catchments or in gutters, they can affect the quality of stored rainwater.
2.4 Disinfection of rainwater
It is not considered necessary to disinfect good quality rainwater, properly protected and
stored, for use for livestock drinking purposes. However in some cases it may be necessary,
for young or ill livestock whose immunity is lowered. The two most common forms of
disinfection are chlorination and ultra-violet treatment. For both of these to be effective the
water should not be turbid, and may require filtration to ensure this is consistently the case.
14
2.4.1 Chlorination
The effectiveness of chlorine is relatively short lived and it will only act on water in the tank
at the time of dosing. Fresh water run into the tank after chlorination may not be fully
disinfected.
Chlorination is effective against harmful bacteria, many viruses and Giardia but it has limited
effect against Cryptosporidium. Chlorination can also remove odours from rainwater by oxidising the responsible chemicals. When chlorine is added to water, it reacts with organic
matter and other impurities in the water – the amount of chlorine needed for disinfection will
depend on the concentrations of these impurities.
To achieve effective disinfection, it is necessary to add sufficient chlorine to provide a free
chlorine residual of at least 0.5 mg/l for a contact time of at least 30 minutes. This can be
measured using a suitable chlorine test kit (for example, a swimming pool kit) if available. As
a general guide, the addition of 40 ml of liquid sodium hypochlorite (12.5% available
chlorine) per 1000 litres of water will provide effective disinfection. The free chlorine dose
will be approximately 5 mg/l. Chlorine imparts a distinct taste and odour that may cause some rejection by livestock. The taste and odour should dissipate in 10 to 14 days (depending
on temperature).
2.4.2 Ultraviolet light irradiation
Ultraviolet (UV) light irradiation can be used to provide continuous assurance of water
quality and is effective against viruses, bacteria and protozoa. UV light systems require
relatively low maintenance and have the advantage of not involving addition of chemicals but
provides no residual disinfecting effect. The UV light could be installed in pipework delivering water from a tank to outlets. If UV light irradiation is used, it is important to install
a system incorporating a sensor that indicates when the device is or is not operational. UV
lamps have a limited effective life and most need to be replaced after between nine and 12 months.
2.5 Legislation applying to livestock drinking water on UK farms
Since 1 January 2006 the hygiene of food production throughout the EU has been covered by
EC Regulation 852/2004 on the hygiene of foodstuffs (EC, 2004). Whilst this regulation does
not make specific reference to livestock drinking water Annex I concerns primary production
and includes a requirement for animal keepers “to use potable water, or clean water,
whenever necessary to prevent contamination”. Clean water is defined in the regulations as
“water that does not contain micro-organisms or harmful substances in quantities capable of
directly or indirectly affecting the health quality of food.” This was interpreted by FSA in
guidance notes issued in 2006 to mean that livestock drinking water should be protected from contamination and keepers should not knowingly permit animals to drink from a
contaminated source (FSA, 2006).
The quality of livestock drinking water is also specified in voluntary Assurance Schemes, for
example the Red Tractor Farm Assurance Dairy Standards (AFS, 2010) states:
Stock must have adequate access to a supply of fresh, clean drinking water. Whilst at
pasture or outdoors, all livestock must be provided with additional water troughs
unless there are sufficient natural water sources to ensure adequate daily access.
This latter requirement indicates that “natural sources” are considered satisfactory provided
they are considered to be “clean”, although “clean” is not further defined in the assurance
standards.
15
2.6 What do we mean by “water quality”?
There are no consistent definitions of water quality with respect to provision to livestock, and
those that are reported depend on the context in which quality is considered. In fact there is a
dearth of information on the impact of water quality on productivity of livestock, and hence the factors that define quality have not been well-characterised. However several aspects of
water quality have been discussed by various researchers and include:
• organoleptic properties (odour and taste);
• physiochemical properties (pH, total dissolved solids, total dissolved oxygen and
hardness);
• the presence of toxic compounds (heavy metals, toxic minerals, pesticides, oils,
organophosphates and hydrocarbons);
• excess minerals or compounds (nitrates, sodium sulphates and iron);
• viruses, bacteria, protozoa and algae.
Some of the most extensive studies of water composition and its influence on productivity
were carried out by Willms and co-workers in Canada who conducted trials comparing
different water sources (Willms et al. 1996, 2000, 2002). They investigated water quality in dams and measured a vast array of water components. However, they were not able to
identify any individual components of water that had a particular influence except that, in
specific experiments, they showed that faecal contamination influenced the palatability of water for stock and hence water consumption and live weight gains rather than causing
disease per se.
2.6.1 Salinity, total dissolved solids (TDS) or total soluble salts (TSS)
Total dissolved solids (TDS) provide a measure of the total inorganic salts dissolved in water
and is a guide to water quality; the measurement also includes substances such as organic
compounds, if present. Salinity (TDS) is used in Australia as a convenient guide to the
suitability of water for livestock watering. Salinity, TDS and total soluble salts (TSS) are all measures of water-soluble constituents commonly used in North America. Sodium chloride is
the first consideration, but other components associated with salinity are bicarbonate,
sulphate, calcium, magnesium and silica, and, a secondary group (lower concentrations) of constituents including iron, nitrate, strontium, potassium, carbonate, phosphorus, boron and
fluoride (Looper and Walder 2002).
Animals under physiological stress, for example due to pregnancy, lactation or rapid growth,
are particularly susceptible to mineral imbalances. Livestock generally find water of high
salinity unpalatable. Water of marginal quality can cause gastrointestinal symptoms and a
reduction in weight gain and milk or egg production. However, livestock can acclimatise
physiologically to some extent to water of higher salinity when the level is adjusted over
several weeks (ANZECC guidelines, 2000).
The US National Academy of Sciences (NAS 1974) noted that water with up to 5000 ppm
TDS can safely be given to dairy cattle, and in some cases water containing 7000 to 10000 ppm TDS has been used without any effect on milk production (Frens 1946). Generally water
with over 10,000 ppm TDS is considered highly saline and the risks are such that its use
cannot be recommended. However Heller (1933) found that dairy cows were able to adapt to
survive on water containing 15000 ppm (1.5%) sodium chloride.
Subsequent to the NAS review, reductions in milk production in dairy cows and in liveweight
gain of cattle were reported at TDS levels of 2700 to 4400 mg/litre (Jaster et al. 1978, Solomon et al. 1995, Challis et al. 1987). Also Saul and Flinn (1985) reported reductions in
16
performance when Hereford heifers were introduced to water containing TDS levels of 5000-
11000 mg/litre.
The ANZECC guidelines (2000) classified levels for different livestock species as shown in
Table 1 and stated that “Salinity is used as a convenient guide to the suitability of water for livestock watering. If water has purgative or toxic effects, especially if the TDS concentration
is above 2400 mg/litre, the water should be analysed to determine the concentrations of
specific ions.”
The tolerance of sheep to saline drinking water may depend on the type of forage consumed.
For example, pen-fed sheep were shown to tolerate up to 13000 mg/litre TDS (Peirce 1966,
1968a). However, with sheep at pasture, lambs showed increased diarrhoea, higher mortality
and lower body weight gains at levels of 13000 mg/litre TDS or reduced body weight gains
and wool production at 10000 mg/litre TDS (Peirce, 1968b).
Looper and Waldner (2002), in defining water quality requirements for dairy cattle presented
the information in Tables A2.1 and A2.2. These guidelines are more stringent than the
ANZECC (2000) guidelines but the two sources are generally in agreement.
Table A2.1 Estimated tolerances of livestock to TDS in drinking water (ANZECC 2000
Salinity or Total dissolved solids (TDS, mg/litre)
Livestock
No adverse
effects on
animals
expected
Animals may have initial
reluctance to drink or there
may be some scouring, but
stock should adapt without
loss of production
Loss of production and
a decline in animal
condition and health;
stock may tolerate
these levels for short
periods if introduced
gradually
Beef cattle 0-4000 4000-5000 5000-10000
Dairy
cattle 0-2500 2500-4000 4000-7000
Sheep 0-5000 5000-10000 10000-13000
Horses 0-4000 4000-6000 6000-7000
Pigs 0-4000 4000-6000 6000-8000
Poultry 0-2000 2000-3000 3000-4000
Table A2.2 Guidelines for use of saline waters for dairy cattle (Looper & Waldner 2002)
Total Dissolved Solids
(ppm)
Comments
Less than 1,000 Presents no serious burden to livestock.
1000 to 3000 Should not affect health or performance, but may cause temporary mild diarrhoea.
3000 to 5000 Generally satisfactory, but may cause diarrhoea especially
upon initial consumption.
5000 to 7000 Can be used with reasonable safety for adult ruminants;
should be avoided for pregnant animals and baby calves.
7000 to 10000 Should be avoided if possible: pregnant, lactating, stressed
or young animals can be affected negatively.
Over 10000 Unsafe: should not be used under any conditions.
17
The response of non-ruminant species to saline drinking water has also been reported. For
example, the incidence of eggshell defects (thin and cracked shells) in laying hens was
increased by an increased intake of mineral salts (Balnave and Scott 1986). Municipal water
supplemented with 250 mg/litre NaCl increased shell defects two fold, while 2000 mg NaCl/litre added to drinking water resulted in defects in up to 50% of all eggs (Balnave and
Yoselwitz 1987, Brackpool et al. 1996). The adverse effect of the saline water, even for short
periods of time during early lay, was not overcome when the water supply was replaced with lower salinity water; notably equivalent levels of sodium chloride in feed did not adversely
affect egg shell quality (Balnave and Zhang 1998). This again raises the important issue of
considering both feed and water as sources of such components.
An increase in water consumption and some initial diarrhoea are common observations when
pigs are introduced to water containing more than 4000 mg/litre TDS, but concentrations as
high as 6000 mg/litre TDS are unlikely to adversely affect pigs that have become accustomed
to the water (Robards and Radcliffe 1987). In experiments in Queensland, pigs reared from
20 to 80 kg showed no reduction in performance and no adverse effects on health when given
water containing up to 8000 mg/litre TDS, although water consumption did increase with increasing salinity, particularly in summer (McIntosh 1982). However other published
studies have indicated variable effects from different substances. The most studied
compounds are nitrates in dairy cattle.
2.6.2 Nitrates in cattle drinking water
According to Grant (1996), nitrate concentrations exceeding 100-150 mg/l drinking water can
cause reproductive disturbances in mature cows and replacement heifers, which will show
lower growing rates, but usually there are no significant milk production alterations at moderately raised nitrate levels in the drinking water. Production and reproduction were
unaffected in dairy cows in consuming water containing 86 mg/litre nitrate-N for almost two
years in a Wisconsin study (Kahler et al, 1974), but some reproductive performance decline was noted in the third year.
Ensley (2000) took water samples from 128 dairy cattle farms in Iowa in order to assess the water quality effects on the productive performances of dairy cows. The results indicated that
higher nitrate concentrations (>20mg/litre nitrate-N) in drinking water cause longer calving
intervals.
Concentrations of less than 10 mg/litre nitrate-N in water are considered safe for dairy cattle
(NRC, 2001). Winks (1963) reported death of calves and cattle in Queensland from drinking
water containing 2200 mg/litre nitrate. He suggested a toxic nitrate concentration for cattle as
somewhere between 300 mg/litre and 2200 mg/litre. In dairy cows, nitrate concentrations up
to 180 mg/litre in drinking water did not increase the concentration of nitrate in milk (Kammerer et al. 1992).
2.6.3 Effect of nitrate on other species
Seerley et al. (1966) concluded that drinking water containing approximately 300 mg/litre nitrate-N had no effect on the health of pigs or sheep and that levels of nitrite-N less than 100
mg/litre over 105 days did not adversely affect pig health. Anderson and Stothers (1978)
similarly reported no ill effects in weanling pigs after 6 weeks of drinking water containing
around 1300 mg/litre nitrate.
However, Sorensen et al. (1994) found no effect on early weaned piglets and growing pigs
from water containing up to 2000 mg/litre nitrate or up to 17 mg/litre nitrite. In experiments
carried out in Queensland, pigs raised from 20 to 80 kg showed no decrease in performance
18
and no adverse effects on health, when given water containing up to 500 mg/litre nitrate or up
to 50 mg/litre nitrite (McIntosh 1981). A national survey of pig farms in the US showed no
association between animal health or performance and drinking water containing up to 460
mg/litre nitrate (Bruning-Fann et al. 1996). However studies by Bergsrund & James (1990)
on poultry showed that water containing more than 20mg/litre nitrates has negative impact on their growth, feed change-over and egg production.
2.6.4 Nitrite
As ingestion of nitrite leads to a more rapid onset of toxic effects than nitrate, the guideline
value for nitrite must be correspondingly lower than that for nitrate. The total dietary intake
of nitrate by livestock needs to be considered when interpreting the trigger values. High
nitrate concentrations in the water supply may indicate that nitrate levels in locally-grown
feed may also be elevated. Trigger values of 30 mg/litre nitrite are recommended for
livestock drinking water (ANZECC 2000). Nitrite levels in water which are over 4 mg/litre
may be toxic to cattle. Symptoms include infertility, reduced gains, abortions, respiratory
distress and eventually death. (Grant 1995).
2.6.5 Sulphates
Hamlen et al (1993) showed that very high concentrations of sulphates in drinking water
(7200 mg/litre) were associated with higher incidence of polioencephalomalacia in cattle.
Loneragan et al (2001) showed that the consumption of water with high quantities of
sulphates (average 583 mg/litre) can cause nutritional disturbances and affected carcass
characteristics of feedlot steers.
2.7 Water quality standards for livestock drinking water
There are no published UK standards setting out the microbiological or chemical quality of
water to be used for livestock drinking although standards have been published in other countries such as Canada, USA and Australia and New Zealand.
The published guidelines for water quality are often based on few data, with little information as to how the guidelines were formulated and how “acceptable” levels of water components
and contaminants were defined. In fact, many of the guidelines do not appear to be based on
experimental data, but rather on the anecdotal experience of people in the field, or
alternatively on standards of drinking water for human consumption.
Two differing approaches have been used in developing guidelines in some countries. A
toxicological approach, as proposed by the Canadian Council of Ministries of the
Environment (CCME 1993), is based on the following principles:
• the method of developing guideline values is transparent and consistent;
• selection criteria and appraisal protocols ensure only valid sound scientific data are used;
• data can be obtained through feeding trials with animals.
Some disadvantages of this approach include the fact that:
• the need to make many assumptions on factors such as, the value of a 'safety factor' for
inter- and intra-species differences, long-term effects, and the contribution of water
consumption to total intake of a chemical;
• no account is taken for the risk of animals consuming the contaminants;
• differing animal ages and condition, climatic conditions and feed types are not usually
addressed;
• interactions with other elements in the metabolism of animals are not considered;
• users of the guidelines have to interpret the suitability of the water in specific cases.
19
An alternative is a more 'holistic' approach, as taken by the Department of Water Affairs and
Forestry (DWAF 1996) in developing the South African guidelines. This approach includes
the use of in situ observations and studies to identify the level of a constituent at which no
adverse effect would be expected, taking into consideration the major synergistic and antagonistic factors affecting the onset of adverse effects. Guidelines are given in the context
of a risk-based approach, with an indication given of contaminant levels that might be
tolerated for short periods of exposure, or following adaptation to the water source. Where possible, differences among animal species and physiological state are considered. A
comparison of these standards is shown in Table A2.3.
Table A2.3 Guidelines and generally considered safe concentrations of some potentially
toxic nutrients and contaminants for livestock drinking water
Looper and
Waldner,
2002
(considered
safe for
cattle)
Socha et al. (2003)
NAS –
Livestock
Standards
(1974)
Canadian
Livestock
Standards
(1987)
ANZEC
C (2000)
Substance
(ppm = mg/litre )
Upper
Limit,
Guideline1
Upper
Level
Maximum
Upper
Level
Trigger
value
(low
risk)a
pH 6.0-8.0 6-8.5 8.5 Element or
compound
Aluminium, ppm 0.50 5 10 5 5
Arsenic, ppm 0.05 0.2 0.2 0.2 0.5 0.5 up to
5b
Barium, ppm 10 1 1
Bicarbonate, ppm 1000 1000
Boron, ppm 5 30 5
Cadmium, ppm 5 0.005 0.05 0.05 0.02 0.01
Calcium, ppm 100 150 1000
Chloride, ppm 100 300
Chromium, ppm 0.10 0.1 1.0 1.0 1.0 1
Cobalt, ppm 1 1.0 1.0 1
Copper, ppm 1 0.2 0.5
0.5 1.0 cattle
0.5 Sheep
5.0 pigs
1.0 cattle
0.4 sheep
5.0 pigs
Fluoride, ppm 2 2 2 2.0 2.0 2
Iron, ppm 2.0 0.2 0.4
Not
sufficientl
y toxic
Lead, ppm 0.015 0.05 0.1 0.1 0.1 0.1
Magnesium, ppm 50 100 2000
Manganese, ppm 0.05 0.05 0.5
Not
sufficientl
y toxic
Mercury, ppm 0.01 0.01 0.01 0.001 0.003 0.002
Molybdenum, ppm 0.03 0.06 0.15
20
Nickel, ppm 0.25 0.25 1.0 1 Nitrate-Nitrogen,
ppm 10 20 100
100 100 400
Phosphorus, ppm 0.7 0.7
Potassium, ppm 20 20
Selenium, ppm 0.05 0.05 0.1 0.005 0.02
Silver, ppm 0.05 0.05
Sodium, ppm 50 300
Sulphates, ppm 500 50 300 1000 1000
Uranium, ppm 0.2
Vanadium, ppm 0.10 0.1 0.1 ND c
Zinc, ppm 5 5 25 25 25 20 Microbial
Total coliforms,
n/litre 150 5 5
Faecal coliforms,
n/litre 100 1 1
1000
Total bacteria,
n/litre 5000 10000 10000
Microcystisd
,
cells/litre
11.5 x 10
6
Cyanotoxine
, µg/litre 2.3
a) Higher concentrations may be tolerated in some situations;
b) May be tolerated if not provided as a food additive and natural levels in the diet are low;
c) ND = not determined, insufficient background data to calculate;
d) Microcystis = Cyanobacteria;
e) Microcystin-LR toxicity equivalents (Cyanotoxin)
2.7.1 Standards for Pesticides
In the absence of specific standards for livestock drinking water authorities in Australia and New Zealand recommend adoption of the Australian Drinking Water Guidelines (NHMRC &
ARMCANZ 1996) should provide a margin of safety for livestock and prevent accumulation
of unacceptable pesticide residues in animal products. Canada has produced guidelines as
shown in Table A2.4 below.
Table A2.4 Canadian water quality guidelines for pesticides in livestock drinking watera
21
2.7.2 Microbiological quality
Bacteria
There is anecdotal evidence that livestock can tolerate relatively high bacterial loadings in
drinking water (Jemison and Jones 2002) although there is actually very little data available.
Beede and Myers (2000) also stated that contamination of a livestock water source by microorganisms typically is not of concern. However, under certain conditions, microbial
populations can explode, creating problems for livestock. Table A2.5 presents a summary of
guidelines for bacterial limits, although the primary sources are relatively obscure. As the
Table shows, the microbiological limits given for livestock water supplies vary considerably.
Table A2.5 Some microbiological standards for livestock drinking water
Reference Animal Bacterial limit
(faecal coliforms per
100ml water)
Adult animals 1,000 MUE* 1995
Young animals 1
Adult cattle <10 Grant 1996
Calves 0
Looper and Walder
2002
Adult animals
Young animals (especially calves)
<10
<1
ANZECC 2000 All livestock <100 (median)
Smith et al. 1993 All stock water <1000 (geometric mean)
>5000 (< 20% of samples)
(NZ research)
*Missouri University Extension
The level of faecal (thermo-tolerant) coliforms provides an indication of faecal contamination,
but does not directly relate to the number of known pathogenic bacteria (i.e. those that may
affect production or health) present in the water. However, as a test, it is more accessible than
the alternative of a full range of specific tests (such as species-specific tests) that would be
required to encompass all of the water-borne microbial pathogens and parasites that could be
present. The other alternative ‘single test’ is one for total bacterial counts but this includes a
greater number of non-infectious or non-pathogenic bacteria, and so has the potential to be
misleading. For this reason, a faecal coliform count is the most cost-effective and practical
test for on-farm use. However it may not be as directly relevant to animal productivity as the detailed suite of tests, or reveal the most appropriate improvement measure for a particular
poor water quality situation.
Protozoan pathogens
A large variety of protozoan pathogens can be transmitted to stock from drinking water
supplies contaminated by animals and their faeces. The risk of contamination is greatest in
surface waters (dams, watercourses, etc) which are directly accessible by stock or which
receive runoff or drainage from intensive livestock operations or human wastes. The
incidence of groundwater contamination by pathogens is generally low, particularly for deep bores and wells. Some shallow groundwater supplies have the potential to be contaminated,
particularly in sandy soils.
Management of water supplies to minimise contamination is the best strategy for protecting
livestock from water-borne microbial pathogens. Effective measures include preventing
22
direct access by stock to watercourses and minimising drainage of waters containing animal
wastes to streams and groundwaters.
Although experimental work has found associations between pathogen (Giardia spp. or
Cryptosporidium parvum.) infection and decreased animal performance in sucking animals
(Harp et al. 1990, Olsen et al. 1995), field trials have found no such association in sucking and adult animals where pathogens were found to be present in the ruminant. In faecal testing
of yearling cattle, Willms et al. (2000) found those that harboured cysts or oocysts of Giardia
spp. or Cryptosporidium spp. (and also nematodes) had the same weight gains as those where no pathogens were detected. However the impact of a clinical loading of such pathogenic
protozoa in adult animals is not known.
Algae
Algal growth in troughs is a common occurrence and an occasional problem in freestanding
water, such as farm ponds, although apart from cyanobacteria, no studies were located
concerning the influence of true algae on the health and performance of livestock.
Cyanobacteria (also known as blue-green algae as they are similar to algae in habitat,
morphology and photosynthetic activity) are a component of the natural plankton population
in healthy and balanced surface water supplies. They are found as single cells or in clumped
or filamentous colonies. Cyanobacteria can move vertically through water by adjusting their buoyancy (Ressom et al. 1994).
Cyanobacteria only become a potential hazard when they are present in large numbers
(blooms). Thus the cyanobacteria of concern are generally freshwater or brackish water
species and are commonly found as ‘blooms’ in slow-flowing, nutrient-rich waters, usually in
the warmer months (Carmichael 1994). Often, there may be more than one species of
cyanobacteria associated with a bloom (Ressom et al. 1994). Highly toxic “scum” material
can form on the water surface, creating a potential danger for livestock and humans.
Some species can also grow on the bottom sediments, sometimes forming coherent mats.
These benthic (attached) taxa can be a problem especially during periods of low flow when
the mats become accessible to livestock. For example, such benthic cyanobacteria mats (Oscillatoria-like species) have been linked to dog deaths (Hamill 2001). Toxins associated
with cyanobacteria are mostly intracellular in healthy blooms and only affect animals
following direct ingestion of cells (either in water or as dried mats left on the shore), or from drinking water where the death of cells has caused a release of toxins into the water supply.
As a guide, ANZECC (2000) indicated that an increasing risk to livestock health is likely
when cell counts of cyanobacteria exceed 11,500 cells/ml and/or the concentrations of
microcystins (a common cyanbacterial hepatotoxin produced by several cyanobacteria taxa
including Microcystis) exceed certain levels. ANZECC advises that algal blooms should be
treated as possibly toxic and the water source withdrawn until the algae are identified and the
level of toxin defined. However shading of water troughs and frequent sanitation will also
minimize algae growth.
2.8 Impact of water quality on performance
There are few published studies that have actually investigated the influence of water quality
on animal productivity. The most comprehensive studies on the impact of water quality and
productivity are the Canadian studies of Willms et al. (1996, 2000, 2002) who investigated
quality in dams (measuring a number of different water components), and also carried out
specific studies on the impact of faecal contamination and palatability. They were not able to
identify any specific components as having particular influence except that faecal
23
contamination influenced water palatability, and hence water consumption and productivity,
as measured by weight gain.
The Willms study (Willms et al. 2002) claimed that the provision of clean water compared
with highly contaminated water improved average daily weight gains by up to 23%. This was
based on several studies over several stock classes (e.g. cows, yearlings, cows and calves), over at least 3 different sites/farms and different seasons. The improvements in water quality
were brought about by techniques such as pumping dam water to troughs to avoid faecal
contamination from cows entering the water and defecating. However they did not directly assess the quality of the trough water, but in many cases the quality of the dam water was
poor. Observations on the behaviour of cattle in the field support the notion that cattle
having access to fresh water will consume more forage. For example, Willms et al. (2000)
observed cattle from dawn to dusk over 5 to 10 days by and found that the animals spent
considerably less time at a “drinking activity”, more time grazing, and less time loafing, when
they had access to fresh water than when drinking from a dam.
The Willms data show a strong avoidance of contaminated water, yet the water available to
cattle directly from dams or from open water sources is often heavily contaminated by faeces,
indicating that water consumption could well be reduced in such situations. . However, given no choice, cattle will drink contaminated water and intake may not be suppressed, except at
concentrations of fresh manure beyond 0.25%. Although they examined a wide range of
chemical and biological characteristics of the water, they concluded that cattle performance
was most influenced by organic compounds that affected smell or taste.
2.8.1 Mineral content and pH, water intake and productivity
The mineral content of water may impact on animal performance. Weeth and co-workers
carried out a series of studies, mostly focussed on the impact of sulphate content of water on water intake (Weeth and Hunter 1971, Weeth and Capps 1972, Digesti and Weeth 1976).
Other studies (Embry et al. 1959, Challis et al. 1987, Ward et al. 1992, Loneragan et al. 2001)
also revealed an impact of sulphate, or of dissolved salts. However the data from these studies are not conclusive as to the level of tolerance or of the impact of sulphate.
Challis et al. (1987) compared the productivity of cows offered well-water containing 4000 to 5000 mg/l of total dissolved solids (mostly as sulphates, but also chlorides and bicarbonates
with some nitrates, in calcium, sodium and magnesium forms) with desalinated water
(produced by reverse osmosis). Groups of cows that received desalinated water drank more
water, consumed more concentrate and produced significantly more milk (nearly 7 kg more
milk per cow per day) than groups given raw well-water. However actual cause and effect
relationships cannot be deduced from this experiment, and given the wide range of results
from different investigators, the impact of a specific component or the interaction of
components may be the primary contributor to the outcome of this particular experiment.
The pH of water may impact on animal health. For example, Grant (1996) indicated that
water with a pH of less than 5.5 may cause problems related to mild acidosis such as reduced
milk yield, depressed milk fat percentage, low daily gains, more infectious and metabolic disease, and reduced fertility. Grant also stated that alkaline water of pH greater than 8.5 may
result in problems related to mild alkalosis such as amino acid and B-vitamin deficiencies,
and symptoms similar to mild acidosis.
2.8.2 Microbial contamination
Beede and Myers (2000) stated that contamination of a livestock water source by
microorganisms typically is not of concern. However, under certain conditions, microbial
populations can explode, creating problems for livestock.
24
Untreated, drinking water for animals is a potential reservoir and transmission route for
Campylobacter (Savill et al. 2003), although it is not actually known whether ruminants are
susceptible to infection via this route (Belton et al. 1999).
Although experimental work has found associations between pathogen (Giardia spp. or
Cryptosporidium parvum) infection and decreased animal performance in sucking animals
(Harp et al. 1990, Olsen et al. 1995), field trials have found no such association in sucking and adult animals where pathogens were found to be present in the ruminant. In faecal testing
of yearling cattle, Willms et al. (2000) found those that harboured cysts or oocysts of Giardia
spp. or Cryptosporidium spp. (and also nematodes) had the same weight gains as those where
no pathogens were detected. However the impact of a clinical loading of such pathogenic
protozoa in adult animals is not known.
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28
APPENDIX 3. Environmental Sustainability of Existing Methods
This task considers in broad terms the existing constraints on water abstractions, the CAMS
process, and the resulting implications for the alternative methods that could be used to
supply natural water to livestock.
3.1 Water Abstraction in England and Wales - background
The sustainable management of water resources in England and Wales is regulated by
European and domestic legislation along with a number of non legislative programmes and
strategies all of which are managed by the Environment Agency. Water abstraction from
surface waters (rivers, lakes, canals and reservoirs) and groundwater in England and Wales is
regulated through a licensing system introduced by the Water Resources Act 1963. The
system was reviewed during the mid 1990’s to deal with problems such as over licensing and
the need to consider the effects of climate change resulting in the publication of the
government paper ‘Taking Water Responsibly’ in 1998.
3.1.1 The Water Act 2003
The Water Act 2003 (“Modernising the Regulation of Water Resources”) enacted as a result
of the review made significant changes to the licensing system:
o all small abstractions, generally under 20 cubic metres per day (m3/d), do not need a licence;
o dewatering of mines, quarries and engineering works, water transfers into canals and internal drainage districts, use of water for trickle irrigation and abstractions in some
areas which were exempt now need a licence;
o administration for making applications, transferring and renewing licences was made simpler.;
o the status of licences has changed significantly, as all abstractors now have a responsibility not to let their abstraction cause damage to others. From 2012, the
Environment Agency will be able to amend or take away someone’s permanent licence without compensation if they are causing serious damage to the environment;
o there is an increased focus on water conservation. Water companies have new duties to conserve water and all public bodies need to consider how to conserve water supplied to premises;
o water companies need to develop and publish water resources management and drought plans. The Environment Agency can encourage transfer of water resources between
water companies and recover costs associated with drought orders and permits.
3.1.2 The Water Framework Directive
The Water Act 2003 also transposes the requirements of the European Water Framework
Directive into UK Law. Its purpose is to enhance the status and prevent further deterioration
in the ecology of aquatic ecosystems and their associated wetlands and groundwater. The
Directive requires inland and coastal waters to reach good chemical and ecological status by
2015, unless an alternative objective can be justified. It also promotes the sustainable use of
water. The licensing system for abstraction and impoundment of water together with the
Catchment Abstraction Management Strategy will help to deliver Directive objectives.
3.2 Catchment Abstraction Management Strategy
In response to the Government paper ‘Taking Water Responsibly’ The Environment Agency
has developed the Catchment Abstraction Management Strategy (CAMS). CAMS provide a framework to assess how much water is readily available on a catchment basis. It is used to
determine the amount of water currently licensed for abstraction and the amount of water
29
needed to sustain the environment and this shows how much water is potentially available for
further abstraction. In certain locations in the catchment where water dependant European
designated sites are located, the Habitats Regulations will need to be considered where
abstraction could impact any part of these sites. Originally launched in 2001 the first
assessment using CAMS for all major catchments was completed in 2008 and currently a review of all of the strategies is being undertaken. It is expected that these will be reviewed
regularly going forward to take account of changes to the amount of water abstracted along
with climate change trends.
3.2.1 The CAMS Methodology
The Environment Agency published ‘Managing Water Abstraction’ in 2010 which sets out
their policy and the regulatory framework within which they intend to manage water
resources in England and Wales. It describes the CAMS methodology in 3 stages as set out in
the figure below:
Figure A3.1 The CAMS Process (Managing Water Abstraction, Environment Agency
2010)
In Stage 1 of the process the water balance for each of the CAMS areas is calculated looking
at river flows, groundwater recharge, abstractions and discharges. An allocation of the
resource is also made for the environment and any other features that may require protection,
for example water dependant conservation sites. This generates a local resource availability for each catchment which will be used to help determine applications for licenses. Resource
availability for England and Wales is shown in Figure 2 expressed as percentages and shows
where water availability is more reliable for a greater percentage of the year.
Stage 2 of the CAMS methodology is the Licensing Strategy which is specific to each of the
CAMS area and is reviewed annually. Each strategy states what resources are available, what conditions will apply to new and varied licenses and whether licenses will be replaced with
the same conditions. Table A3.1 shows the different types of status that will be assigned
based on the low flow levels.
All new and reviewed licenses will be time limited and will have what is known as a
Common End Date. Licenses will usually be in force for 12 years. The conditions attached
to a license may also include restrictions on abstraction during lower flows (known as ‘Hands
Stage 1:
Resource Assessment
Stage 2: Licensing Strategy
Including: Strategy Actions Catchment time limiting policy Protected rights and lawful use Reviewed annually
Stage 3: Measure Appraisal Process
RSA RBMP Investigation Cost Analysis WR Planning
Water Company Plans Consultation 1
st cycle RBMP
Solutions
RSA sustainable solutions Alternative
objectives
30
off flows’ and ‘hands off levels’) and as less water becomes available, either through drought
or an increase in abstraction licenses, these restrictions could be in place for longer. License
can be reviewed periodically and the conditions modified where circumstances may have
changed within the catchment since the license was issued, for example the closure of a
sewage treatment works.
Figure A3.2 CAMS resource availability (Managing Water Abstraction, EA, 2010)
Where an abstraction of more than 20m3/day is need requiring an abstraction license, it is
important to check the Licensing Strategy for a relevant CAMS area to determine the reliability of the water source on an annual basis. If water availability is scarce and it is likely
to mean to licence will contain restriction on abstraction which would require the farmer to
look at alternative supplies when water availability was scarce. Information on local CAMS is available on the Environment Agency website http://www.environment-
agency.gov.uk/business/topics/water/119927.aspx
Stage 3 of the CAMS Methodology is the Measures Appraisal Process where the
Environment Agency will review catchments / waterbodies not meeting the objectives of the
Waste Framework Directive. Such areas may be fed through the Restoring Sustainable
Abstraction (RAS) Programme with investigations being undertaken to determine where the
problem lies taking into account the cost/benefit of any mitigating measure when developing
a mitigation scheme and any actions will be fed into individual River Basement Management
Plans (RBMP). Stage 3 of the CAMS methodology can indirectly impact on anyone wishing to abstract more than 20m3/day of water and should be considered before making an
application to abstract water as the actions may impact on the conditions of a licence, ie
restrictions on abstraction or short duration licences. RBMP for all rivers in England and
Wales are available to view on the Environment Agency website http://www.environment-
agency.gov.uk/research/planning/33106.aspx
31
Water available Water likely to be available at all flows including low flows.
Restrictions may apply.
No water available No water is available for further licensing at low flows. Water may be
available at higher flows with appropriate restrictions
Over licensed Current actual abstraction is such that no water is available at low
flows. If existing licences were used to their full allocation they could
cause unacceptable environmental damage at low flows. Water may
be available at high flows with appropriate restrictions.
Over abstracted Existing abstraction is causing unacceptable damage to the
environment at low flows. Water may still be available at high flows with appropriate restrictions.
Table A3.1 Status of resource availability
3.2.2 When is an Abstraction Licence required
A licence is required for any abstraction of water at more than 20m3/day (20,000 litres per
day) from a river, stream lake, well, etc. An application is made to the Environment Agency along with supporting information for consideration. The Environment Agency as part of its
determination of the application will check the quantities applied for and that the purpose of
the abstraction is reasonable and potential impacts on the environment and other water users are acceptable. On completion of the determination process the EA will either issue a licence
either as applied for, or with conditions that restrict the abstraction to protect the environment
or other users. In certain cases we may have to refuse the application.
Before making an application it is advisable to check the CAMS report for the area to get an
idea of the likelihood of an application being successful and to gain an idea as to whether
restrictions may apply which may impact on the frequency of the availability of the water.
Anyone is entitled to apply for a licence, even if the CAMS states that water may not be
available. However, any determination of an application and any subsequent issue of a licence must ensure that the abstraction will not have a detrimental impact on the local
environment or existing protected rights and that it complies with the requirements of the
Habitats Regulations.
The Environment Agency has stated that CAMS applies to those abstractions that have a net
impact on the environment. Applications will be made for licences that are nonconsumptive in nature (i.e. 100% of the abstracted water is returned to the catchment) or abstractions that may
have beneficial effects for the environment and these will be determined in the same way as
all other applications. It is important to note that the Environment Agency acknowledge that
the CAMS overview of resource availability is only the first stage of the licence determination
process. It provides an indication of the availability of water but all licence applications will
still be considered under the requirements of the legislative process. Local issues of
derogation and environmental impact will always be assessed and may override the status of a
unit as defined in the CAMS report.
3.2.3 Sustainability of abstractions below 20m3/day
For all abstractions below 20 m3/day (20,000litres per day) there is no longer a requirement to
have a licence. Many farmers will fall below this level or abstract below it to avoid the need
to obtain the licence. The impact on water availability must be considered if a large
percentage of holdings within a catchment abstracted water below the threshold i.e would the
cumulative effect of all of these abstractions impact significantly on the availability of water?
The Hampshire Avon CAMS includes all licensed sites using less than 20 m3 as the process
started before the change in regulations came into effect. Commentary within the report
32
suggests that the impact of these additional abstractions is less than 1% of the total
abstractions for the catchment therefore the impact of an increase in small scale abstractions is
unlikely to have a detrimental effect on the water resource availability.
3.3 Implication of CAMS for water abstractions in DTCs
The effect of CAMS applied to the three DTC catchments are considered below.
3.3.1 Case study: CAMS for the Eden catchment
The Catchment Abstraction Management Strategy for the Eden and Esk catchments was
published in April 2006 and sets out how water abstraction will be managed in the catchment
until 2011. A copy of the report can be found at http://publications.environment-
agency.gov.uk/pdf/GENW0306BKIM-E-E.pdf.
There are two main areas in this CAMS, the catchments of the River Eden, and the River Esk
south of the border with Scotland. The River Eden is located between the Pennines and the
Lake District Fells and has it’s headwaters in the Yorkshire Dales National Park. The dominant rock types in the Eden valley area are Carboniferous limestone, which forms the
edges of the valley, and Permo-Triassic sandstone, which crops out in the middle of the
valley. The highly permeable Penrith Sandstone and the less permeable, but still important, St
Bees Sandstone, form the Eden valley aquifer, which is critical to agricultural, public and
industrial water supply. This area includes a range of habitats of high conservation value; the
River Eden is considered important on both a national and a European scale. Habitats in the
area vary from upland fells and moorland in the Lake District and Yorkshire Dales National
Parks and the Pennines, to the rural river valleys lower down in the catchment. They include
terrestrial, aquatic and wetland sites, many of which are designated for their environmental value (CAMS Eden and Esk, April 2006, EA).
The report states that for both the Upper Eden and tributaries and the Lower Eden Water Resource Management Unit (WMRU) which covers both surface waters and groundwaters,
water is available at low flows and the Licensing Strategy states that there is water available
for further licensing. Therefore a livestock unit wishing to abstract more than 20m3/day is
likely to be granted an abstraction licence as resource is currently available. The licence may
include conditions restricting abstraction during low flows although Table 5 of the report sets
out the amount of water available at specific assessment points within the Upper Eden
catchment and also the number of days abstraction would be allowed in an average year. It
ranges from 365 days down to 245 days (average year) so there should be a relatively frequent
supply. Similarly for the lower Eden has water available for abstraction between 248 and 365
days (Table 24 of the Catchment Abstraction Management Strategy cited above).
3.3.2 CAMS for the Hampshire Avon catchment
The Catchment Abstraction Management Strategy for the Hampshire Avon was published in
March 2006 and sets out how water abstraction will be managed in the catchment until 2011. A copy of the report can be found at http://publications.environment-
agency.gov.uk/pdf/GESW0206BKHY-E-E.pdf
The Hampshire Avon CAMS area comprises the entire catchment of the River Avon and its
tributaries. The area covers parts of Wiltshire, Hampshire and Dorset, with a catchment area
of approximately 1,700km2. The main tributaries of the Avon are the River Nadder, River
Wylye, River Ebble and the River Bourne. There are also numerous streams draining to the
Avon from the New Forest (CAMS Hampshire Avon, March 2006, EA).
33
The report splits the catchment into 4 Water Resource Management Units (WMRU) which
covers both surface waters and groundwaters:
o WRMU 1 is the largest WRMU in the Hampshire Avon CAMS catchment, covering the entire lower River Avon and its tributaries below Salisbury. It has 226 abstraction licences (439 licensed abstraction points) both for groundwater and surface water sources.
The surface water assessment point (AP 1) is at the tidal limit of the River Avon and has
been assessed as being “over-abstracted”. o WRMU 2 covers the Eastern Avon, Western Avon, Nine Mile River and the upper Avon down to Salisbury. The unit contains 142 abstraction licences (329 licensed abstraction
points) from groundwater and surface water sources. The surface water assessment point
(AP 2) for this WRMU is at Salisbury on the main River Avon, which has been assessed
as being “over-licensed”.
o WRMU 3 covers the majority of the River Wylye and its tributaries. The tributaries include the River Till and the Chitterne Brook. It contains 96 abstraction licences (185
licensed abstraction points) from groundwater and surface water sources. The surface
water assessment point (AP 3) for this WRMU is at South Newton on the River Wylye,
which was assessed as being “over-abstracted”. o WRMU 4 covers the River Bourne. It contains 38 abstraction licences (79 licensed abstraction points) from groundwater and surface water sources. The surface water
assessment point (AP 4) for this WRMU is at Laverstock near the confluence with the
River Avon, which has been assessed as being “over-licensed”.
The report states that there will be a presumption against issuing new consumptive licences
from surface water without a restrictive flow condition. It defines water for agricultural as
50% consumptive so there is a possibility that a licence for abstraction may be issued but with
restrictions attached. The report shows that currently the units are either “over-abstracted” or “over licensed” for a significant part of the year and water is scarce at both low and medium
flows. For example for WRMU1, based on the full licensed scenario (i.e. everyone using their
full licensed volume), any new licence holders would be able to abstract water for approximately 43% (157 days) of the year in an average year. In a dry year, such as 1992, this
would fall to 19% (69 days), but rise to 68% (247 days) in a wet year such as 1993 (CAMS
Hampshire Avon, March 2006, EA). However there may be water available for licensing at higher flows subject to restrictive flow conditions. Holdings using more the 20 m3/day water
need a licence.
3.3.3 CAMS for the Broadlands catchment
The Catchment Abstraction Management Strategy for the Broadlands was published in March
2006 and sets out how water abstraction will be managed in the catchment until 2011. A copy
of the report can be found at http://publications.environment-
agency.gov.uk/pdf/GEAN0306BKIZ-E-E.pdf
The area includes the catchments of the Rivers Thurne, Ant, Bure, Wensum, Blackwater, Tud,
Yare, Tiffey and Tas together with the Dove and Waveney. The area also includes the shallow lakes of the Broads, together with a coastal zone between Lowestoft & Happisburgh. There
are over 800 abstraction licences (over 130 of which are time limited) in the Broadland Rivers
CAMS area, the majority of these being groundwater abstractions. A large number of
agricultural businesses hold abstraction licences to enable them to grow irrigated crops such
as potatoes, sugar beet and salad crops. Agricultural growing, processing and retail activities
are an important component of the rural economy. Water is used in industrial operations for
mineral extraction, food production, brewing and agrochemical production (CAMS
Broadlands Catchment, March 2006, EA).
34
The report splits the catchment into 8 Water Resource Management Units (WMRU) which
covers both surface waters and groundwaters) from A to H. The River Wensum is covered by
WMRU D & E.
o WMRU D – Wensum SAC. The CAMS states the water resource availability status of this WRMU is ‘Over Licensed’ at low flows. The target status for this WRMU in 2011 is
to reduce the amount of licensed abstraction but to remain within the Over Licensed
resource availability status. The whole of the Special Area of Conservation (SAC) designated reach of the Wensum is managed as a combined Water Resource Management
Unit to improve the resource availability at the critical downstream assessment point to
support abstraction, recreation and conservation.
For anyone wishing to make an application for a new licence it is stated that, in general,
groundwater applications will not be considered. For surface water abstractions,
- At low flows there is no water resource available for consumptive purposes, although non consumptive use may be considered.
- Limited quantities for consumptive purposes may be available at high flows. - New licences and variations to existing licences will be subject to a time-limit of 31 March 2018 unless more restrictive measures are required to protect water related
conservation sites.
o WMRU E - Lower Wensum and River Tud. The CAMS state the water resource availability status ‘Over Licensed’ at low flows and the target status for this WRMU in
2011 is to remain at the current resource availability status.
Again as for WMRU D above for anyone wishing to make an application for a new
licence it is stated that, in general, groundwater applications will not be considered. For surface water abstractions,
- At low flows there is no water resource available for consumptive purposes, although non consumptive use may be considered.
- Limited quantities for consumptive purposes may be available at high flows. - New licences and variations to existing licences will be subject to a time-limit of 31 March 2018 unless more restrictive measures are required to protect water related
conservation sites
- Abstraction licence applications are issued on a first come first served basis.
3.3.4 CAMS - Summary for the three DTCs
To summarise, looking specifically at the DTCs any holding wishing to apply for an
abstraction licence in the Eden catchment is likely to be successful in obtaining a licence,
although it may include restrictions for low flows looking at Figure 2 the percentage time for
resource availability for the area ranges between 70% and 95% annually indicating a frequent and reliable supply of water. However for the Hampshire Avon and the Wensum catchment
water resource availability is significantly lower with both having WMRUs which are either
over licensed or over abstracted. Figure 2 the percentage time for resource availability for the area ranges between 50% at best down to under 30%. This will need further investigation and
management by the Environment Agency through the RSA and RBMP programmes. As
livestock holdings are considered to be 50% consumptive it suggests that obtaining a licence is not impossible but any licence issued is likely to have severe restrictions on when water is
available for abstraction and this cold be a problem for a holding requiring resource
availability all year round and more so in summer months when drinking water requirements
are higher and the prohibitive conditions are at their most restrictive. A secondary source of
water will need to be available in these circumstances, this could either be mains supply or
abstraction below 20m3 per day supported by mains.
35
APPENDIX 4. DTC case study constraint maps
Contents
4.1 Introduction 4.2 Methods
4.3 Rainwater harvesting
4.3.1 Rainwater harvesting calculation
4.3.2 Number of livestock per Defra category
4.3.3 Roof areas
4.3.4 Rainfall during housed periods
4.3.5 Rainwater harvesting efficiency
4.3.6 Livestock water requirements
4.3.7 Percentage of livestock water requirements that may be supplied by rainwater harvesting
4.4 Hydraulic ram pumps
4.4.1 Pumps utilising existing river fall
4.4.2 Pumps utilising an artificial fall
4.4.3 Livestock grazing areas
4.5 Solar and wind powered pumps
4.5.1 Solar pumps
4.5.2 Wind pumps
4.6 Sustainability of catchment abstraction
4.6.1 Holding level data
4.6.2 Percentage of holdings that require an abstraction license
4.7 Susceptibility to climate change
4.7.1 Climate Projections data
4.7.2 Rainwater harvesting
4.7.3 Wind powered pumps
5 Constraint maps
5.1 Rainwater harvesting (1961-1990) 5.2 Hydraulic ram pumps 5.3 Wind pumps 5.4 Water abstraction 5.5 Rainwater harvesting (2050s)
4.1 Introduction
This Appendix outlines the methods, outputs and main results of the GIS mapping and data
analysis required by the project objectives. Results are mapped at a grid cell level for the
River Eden and Tributaries, River Wensum, and River Hampshire Avon demonstration test
catchments (DTCs, Figure A4.1).
The major towns and cities within the DTCs, and the elevation of the land are shown in
Figures A4.2a-c. The number of cattle, poultry, sheep and pigs from the 2009 ADAS Land Use Database (see later section) are shown at a 1km2 grid cell level for the DTCs in Figures
A4.3a-d.
36
Figure A4.1 Location of the three DTCs within England and Wales
Figure A4.2a. Elevation of the River Eden and Tributaries DTC
37
Figure A4.2b Elevation of the River Wensum DTC
Figure A4.2c Elevation of the River Eden and Tributaries DTC
3
8
Figure A
4.3a Number of cattle (head/ km2) within the DTCs, taken from the 2009 ADAS Land Use Database
3
9
Figure A
4.3b Number of poultry (head/ km2) within the DTCs, taken from the 2009 ADAS Land Use Database
4
0
Figure A
4.3c Number of sheep (head/ km2) within the DTCs, taken from the 2009 ADAS Land Use Database
4
1
Figure A
4.3d Number of pigs (head/ km2) within the DTCs, taken from the 2009 ADAS Land Use Database
42
4.2 Rainwater harvesting
4.2.1 Rainwater harvesting calculation
Whilst livestock are housed, or are kept near to farm buildings, rainwater may be harvested as a source of water for livestock during that period. The amount of harvestable rainwater
available for livestock was determined by calculating the roof area of farm buildings and
multiplying that by the amount of rainwater available for harvesting during the livestock housing period as:
W = (N*A)*(R*(E1*E2))
where,
W = Water available (l)
N = Number of livestock in a given Defra census livestock category
A = Total roof area (m2)
R = Total rainfall during the housing period for that livestock category (mm)1
E1 = Rainwater harvesting collection efficiency (proportion)
E2 = Rainwater harvesting filter efficiency (proportion)
The amount of harvestable rainwater was calculated at a 1 km2 grid cell level for each major
livestock type (cattle, poultry, sheep, and pigs). The variables in the harvesting calculation
were determined using the methods listed below.
4.2.2 Number of livestock per Defra category
Livestock requiring housing will be kept in buildings that may be used for rainwater
harvesting. To determine the number of livestock (and therefore the total roof area) in a 1 km2
grid cell, the following method was used:
Estimates of livestock numbers at a 1 km2 grid cell level were taken from the 2009 ADAS
Land Use database2. This dataset was derived from features in OS Strategi
® mapping
3; the
Common Land database4 and the Land Cover Map of Great Britain5 (LCMGB, 1990), which
were used to determine the area of non-agricultural land in 1 km2 grid cells (split into
categories including urban areas, rough grazing, woodland, sea, and fresh water). The
remaining land was classed as agricultural land, which was then split into arable land and
grassland using proportions from the LCMGB data. The 1 km2 land area values were then
adjusted at a parish and district level to match the total amount of agricultural land reported
for each district in the Defra 2009 agricultural census4. For each parish (England) and
community group (Wales), the total area of arable and agricultural grassland, and rough
grazing land was calculated, and the density of livestock on this land determined (number of animals per hectare). The livestock density was multiplied by the area of land relevant to that
livestock type in each 1 km2 grid cell (e.g. rough grazing and agricultural grassland for sheep)
to produce a 1 km2 dataset of livestock numbers for each Defra census category. The Defra
livestock categories used in these analyses are listed in Table A4.1.
The numbers of livestock listed in the ADAS Land Use Database were adjusted to account for
animals kept permanently unhoused in some farms, as only housed animals will have access
1 1mm of water is the equivalent of 1 litre/ m2 2 Defra projects NT2206 and NIT 18 3 Ordnance Survey, 2011 4 Defra, 2011 5 Centre for Ecology and Hydrology, 2011
43
to the harvested rainwater. The number of ewes (categories M1 and M7) was reduced by
60%, and sows (categories L1, L2, and L3) by 35%, as suggested by ADAS livestock experts.
The categories of sheep which are usually unhoused all year round (M4, M9, M13, M14, and
M17) were not included in any of the calculations.
4.2.3 Roof area
The 1km2 housed livestock numbers were multiplied by relevant roof area values (m
2/ head).
Standard roof areas for livestock housing were taken from examples in the available literature
for four types of livestock; sheep6, cattle7, pigs8, and poultry9 (Table A4.2). For cattle, roof
areas for other associated buildings (e.g. milking parlours) were also researched by ADAS
livestock experts for inclusion in the roof area calculation (Table A4.3). No additional areas
were included for sheep, as they are housed outdoors for much of the year, so do not require
additional buildings likely to be large enough to support rainwater collection. There is also no
extra area for pigs and poultry, as the presence of additional buildings will depend largely on
holding size, which is not reported in the ADAS Land Use Database.
As the categories used in the literature for livestock housing differ from the Defra census categories, they were matched together by ADAS livestock experts, taking averages where
there the census category covers more than one of the housing categories. The values for
housing and non-housing roof areas were then combined to give an estimate of total roof area
value per animal for each livestock category (Table A4.4).
The total roof area available in a 1 km2 cell was calculated for each livestock type by
multiplying the number of housed livestock in each census category by the matching roof area
coefficient, and summing the categories together for sheep, pigs and poultry. The different
categories of cattle have different housing periods (see later), and were kept separate in the analyses until a later stage to improve the accuracy of the results.
6 BSI. 1990. Buildings and structures for agriculture. Code of practice for design and construction of
sheep buildings and pens 7 BSI. 2005. Buildings and structures for agriculture. Code of practice for design and construction of
cattle buildings 8 BSI. 1990. Buildings and structures for agriculture. Code of practice for design and construction of
pig buildings 9 Pringle, R.T. 1981. A design guide to mechanically ventilated livestock housing
44
Table A4.1 Defra livestock categories used in analysis.
Livestock type Defra
census ID
Sub-category
K201 Male <1yr
K202 Beef female <1yr
K203 Dairy female <1yr
K204 Male 1-2yr
K205 Beef female 1-2yr
K206 Dairy female 1-2yr
K207 Male 2yr+
K208 Beef female 2yr+ no offspring
K209 Dairy female 2yr+ no offspring
K210 Beef herd (female 2yr+)
Cattle
K211 Dairy herd (female 2yr+)
M1 Ewes intended for further breeding
M4 Intended for slaughter
M7 Ewes intended for breeding (first time)
M9
Breeding sheep 1 year
and over
Rams for service
M13 Females, 1 year and over
M14 Males, 1 year and over
Sheep
M17
Other sheep and
lambs
Lambs, under 1 year
L1 Sows in pig
L2 Gilts in pig
L3 Suckled or dry sows kept for further breeding
L4 Boars for service
L5
Breeding pigs
Gilts 50kg+ (intended to be kept/sold for
further breeding)
L7 Barren sows for fattening
L10 110kg+
L11 80 - 110kg
L12 50 - 80kg
L13 20 - 50kg
Pigs
L14
All other pigs by
liveweight
under 20kg (including suckling pigs)
N2 Pullets, point of lay
N31 Intensive
N32 Barn
N33
Hens and pullets
laying eggs for eating
Free range
N5 Layer breeders
N6 Broiler breeders
N7
Breeders
Cocks and cockerels
N10 Broilers (table chickens)
N13 Ducks
N14 Geese
N15 Turkeys
Poultry
N16
Other poultry
All other birds
45
Table A4.2 Estimated roof areas for livestock housing
Livestock type Housing category Housing area (m2/ head)
Dairy 200kg 6.00
Dairy 300kg 7.00
Dairy 400kg 8.00
Dairy 500kg 8.50
Dairy 600kg 9.00
Dairy 700kg 10.00
Dairy 800kg 11.00
Beef 200kg 3.00
Beef 300kg 3.60
Beef 400kg 4.20
Beef 500kg 4.60
Beef 600kg 5.10
Cattle
Beef 700kg 5.40
Creep lambs 0.40
Hoggs 22kg 0.55
Hoggs 35kg 0.80
Ewes with lambs 1.80
Sheep
Pregnant ewes 1.40
<20kg 0.20
40kg 0.35
60kg 0.50
80kg 0.70
Pigs
100kg 0.85
Poultry All poultry 0.14
Table A4.3 Estimated roof areas for non-housing farm buildings.
Livestock type Building type Roof area (m2/ head)
Straw store 1
General purpose building 4.5
Milking parlour and milk plant room (K211
dairy cattle only) 1.5
Cattle
Silage clamp 6
46
Table A4.4 Housing area per head for each Defra census category.
Livestock
type
Defra
census
ID
Livestock housing
categories
Housing area
(m2/ head)
Non-housing
area (m2/ head)
Total roof
area (m2/
head)
K201 Beef 200-300kg 3.30 11.50 14.80
K202 Beef 200-300kg 3.30 11.50 14.80
K203 Dairy 200-300kg 6.50 11.50 18.00
K204 Beef 200-500kg 3.85 11.50 15.35
K205 Beef 200-500kg 3.85 11.50 15.35
K206 Dairy 200-500kg 7.38 11.50 18.88
K207 Beef 500-700kg 5.03 11.50 16.53
K208 Beef 500-700kg 5.03 11.50 16.53
K209 Dairy 500-700kg 9.17 11.50 20.67
K210 Beef 500-700kg 5.03 11.50 16.53
Cattle
K211 Dairy 500-700kg 9.17 13.00 22.17
M1 Breeding ewes 1.60 0.00 1.60
M4 N/A 0.00 0.00 0.00
M7 Breeding ewes 1.60 0.00 1.60
M9 N/A 0.00 0.00 0.00
M13 N/A 0.00 0.00 0.00
M14 N/A 0.00 0.00 0.00
Sheep
M1710 Hoggs 22-35kg 0.68 0.00 0.68
L1 100kg 0.85 0.00 0.85
L2 80-100kg 0.78 0.00 0.78
L3 100kg 0.85 0.00 0.85
L4 100kg 0.85 0.00 0.85
L5 60-80kg 0.68 0.00 0.68
L7 100kg 0.85 0.00 0.85
L10 100kg 0.85 0.00 0.85
L11 80-100kg 0.78 0.00 0.78
L12 40-80kg 0.52 0.00 0.52
L13 20-60kg 0.35 0.00 0.35
Pigs
L14 <20kg 0.20 0.00 0.20
N2 All poultry 0.14 0.00 0.14
N31 All poultry 0.14 0.00 0.14
N32 All poultry 0.14 0.00 0.14
N33 All poultry 0.14 0.00 0.14
N5 All poultry 0.14 0.00 0.14
N6 All poultry 0.14 0.00 0.14
N7 All poultry 0.14 0.00 0.14
N10 All poultry 0.14 0.00 0.14
N13 All poultry 0.14 0.00 0.14
N14 All poultry 0.14 0.00 0.14
N15 All poultry 0.14 0.00 0.14
Poultry
N16 All poultry 0.14 0.00 0.14
4.2.4 Rainfall during housed periods
10 The majority of lambs are unhoused, so the value for M17 is not included in the analysis for sheep
47
The amount of rainfall available for harvesting was analysed using the Met Office long-term
average climate data for the baseline period (1961-1990)11, at a 5 x 5 km grid cell resolution.
These data include averages of precipitation rate (mm day-1) for each month, with
precipitation defined as all rain, snow, sleet and hail. Each of the 1 km2 cells used in the
livestock census was assigned the precipitation rate of the 5 x 5 km cell it falls within when
overlaid in ArcGIS, producing a precipitation rate dataset at a 1 km2 resolution.
As rainwater collection can only practicably be used for livestock while they are being housed indoors or near to housing areas, the amount of precipitation during the housed period was
calculated. Livestock housing days were estimated for the NARSES project by ADAS
livestock experts12, and adjusted for some categories for the purpose of this project (Table
A4.5). The average precipitation rate for each month was then multiplied by the number of
days each livestock census category is housed during that month and totalled to calculate the
amount of precipitation during the housing period. Dairy cattle are only housed for part of the
year, but will also have access to some of the collected water during the summer months for
milking. They are classed as having some access to collected water all year round, but with a
separate analysis for the outdoor months, as drinking requirements and water availability will
be different during this time.
11 Met Office, 2011, available at:
http://www.metoffice.gov.uk/climatechange/science/monitoring/ukcp09/download/index.html 12 Defra projects AM0101 and AM0133
4
8
Table A
4.5 N
umber of days in the month
that livestock
are housed indoors
12.
Defra
cen
sus ID
January
February
March
April
May
June
July
August
September
October
November
December
Total
Breeding
ewes: M1
& M7
0
0
15
0
0
0
0
0
0
0
0
0
15
All other
sheep
0
0
0
0
0
0
0
0
0
0
0
0
0
All poultry
31
28
31
30
31
30
31
31
30
31
30
31
365
All pigs
31
28
31
30
31
30
31
31
30
31
30
31
365
Cattle:
K201,
K202 &
K203
31
28
31
3
0
0
0
0
0
2
30
31
156
Cattle:
K204,
K207 &
K208
31
28
31
8
0
0
0
0
0
8
30
31
167
Cattle:
K205
31
28
31
6
0
0
0
0
0
6
30
31
164
Cattle:
K206
31
28
31
5
0
0
0
0
0
4
30
31
160
Cattle:
K209 &
K210
31
28
31
6
0
0
0
0
0
5
30
31
162
Cattle:
K211
(winter)
31
28
31
12
0
0
0
0
0
11
30
31
174
Cattle:
K211
(summer)
0
0
0
18
31
30
31
31
30
20
0
0
191
Cattle:
K211 (all)
31
28
31
30
31
30
31
31
30
31
30
31
365
49
4.2.5 Rainwater harvesting efficiency
The amount of rainwater that can be successfully harvested will depend on the efficiency of
water collection and filtration equipment, which will lose some of the potential rainwater in
the harvesting process. From the figures for collection efficiency coefficients available, the higher values for corrugated steel (0.95) and corrugated cement fibre (0.90) were used, as
these are the more common collection systems currently in use. To calculate a single
proportion value for collection efficiency (E1), the two efficiency values were multiplied together. One value for filter efficiency (E2) was available, which was multiplied by the
collection efficiency in the rainwater harvesting equation to give a total efficiency proportion
value (E) of 0.835, as
E = (corrugated steel*corrugated cement fibre)*filter efficiency
4.2.6 Livestock water requirements
The outputs of previous sections were multiplied together to estimate the amount of rainwater
that can be harvested for each major livestock type at 1 km2. The amount of rainwater
available for harvesting was then compared to the total amount of water needed by the
livestock to determine how much of the requirement can be met by using this method.
Water requirements were obtained from the relevant literature as reported in previous chapters
of this report, and matched to the livestock census categories (Table A4.6). The water
requirements include daily values for drinking water, and annual figures for wash water. The
daily drinking water requirements were multiplied by the number of days each category of
livestock was housed, and summed with the annual value for wash water to give the total
amount of water needed for that livestock category (Table A4.7). Dairy cattle are classed as having access to collected water all year round, but will only drink 50% of their daily water
requirement from this source during the summer milking period (191 days)13.
Poultry and pig production operates in cycles, and the numbers given for some categories in
the census will be representative of one of those cycles at that point in time, rather than the
total number of animals produced over a year. As such, census data cannot be multiplied by the water requirements of an individual animal to get an annual value. In this case, census
numbers were multiplied by the amount of water needed by poultry during all cycles possible
in a year. To do this, the amount of water needed for each cycle was multiplied by the number
of cycles possible in a year, including the days needed for clearing out the cages (e.g. 7 days),
as:
T = ((C1*D))*(H/C2)) +W
where,
T = Total water requirement (l) C1 = Cycle length (days)
D = Daily water requirement (l)
H = Housing length (365 days) C2 = Cycle length including clear out time (days)
W = Annual wash water value (l)
4.2.7 Percentage of livestock water requirements that may be supplied by rainwater
harvesting
13 http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2038/ANSI-4275web.pdf and
http://www.progressivedairy.com/index.php?option=com_content&view=article&id=6064:water-
intake-determines-a-dairy-cows-feed-intake-and-milk-production&catid=154:past-articles&Itemid=229
50
The livestock water requirements were multiplied by the livestock numbers in the ADAS
Land Use Database, as modified according to earlier sections, and compared to the rainwater
availability. The percentage of livestock water requirements that could be supplied from
harvestable rainwater during housing periods (r) was calculated for three of the major
livestock types (sheep, pigs, poultry), by summing the livestock requirements and amount of harvestable rainwater as:
r = (∑R /∑L)*100 where,
R = Rainwater available for harvesting (l)
L = Livestock water requirements (l)
Each of the cattle categories were housed for different lengths of time, so the percentages
were calculated separately for each category. To give an overall percentage value for cattle, a
weighted average of the percentages for each cattle category was used. This produced a 1km2
dataset of percentage values for cattle, sheep, pigs and poultry, which were mapped for the
three DTCs for cattle (Figure A4.4a); poultry (Figure A4.4b); sheep (Figure A4.4c); and pigs
(Figure A4.4d).
5
1
Table A
4.6 L
ivestock
water req
uirements used in analysis.
Livestock type
Defra cen
sus ID
Livestock category
Cycle dura
tion
(days)
Drinking w
ater
per hea
d per day
(l)
Wash
water per
head per year (l)
K211
Dairy cow herd
365
90.61
29.00
K205; K208; K210; K206;
K209
Beef cows & heifers
365
20.00
0.00
K204; K207
Dairy & beef bulls
365
20.00
0.00
Cattle
K201; K202; K203
Cattle <1yr
365
12.50
0.00
N10
Broilers
133
0.09
1.14
N13; N14; N16
Ducks, geese & other birds
56
0.20
2.71
N15
Turkeys
406
0.20
0.24
N2
Pullets
406
0.22
0.47
N31
Laying hens – caged
322
0.19
0.94
N32; N33
Laying hens - non caged
63
1.22
4.13
Poultry
N5; N6; N7
Broiler breeders, layer breeders
& cocks
140
0.58
4.37
L1; L2; L3
Sows
365
13.73
453.22
L5
Maiden gilts
365
5.50
0.00
L7
Barren sows
365
5.50
0.00
L14
Weaners (20kg)
365
1.80
104.39
L12; L13
Growers (50kg)
365
4.20
135.42
L10; L11
Finishers
365
5.60
0.00
Pigs
L4
Boars
365
10.00
0.00
M1; M4; M7
Ewes
365
4.56
0.75
M17
Lambs
365
2.65
0.75
Sheep
M14; M9; M13
Rams & other adult sheep
365
3.30
0.75
52
Table A4.7 Livestock water requirements during the housed period.
Category Defra census ID Housing duration
(days)
Total water
requirement during
housed period (l)
K201 156 1950
K202 156 1950
K203 156 1950
K204 167 3340
K205 164 3280
K206 160 3200
K207 167 3340
K208 167 3340
K209 162 3240
K210 162 3240
Cattle
K21114 365 24448
M1 15 69
M4 0 0
M7 15 69
M9 0 0
M13 0 0
M14 0 0
Sheep
M17 0 0
L1 365 5466
L2 365 5466
L3 365 5466
L4 365 3650
L5 365 2008
L7 365 2008
L10 365 1953
L11 365 1953
L12 365 1520
L13 365 1520
Pigs
L14 365 671
N2 365 29
N31 365 72
N32 365 79
N33 365 79
N5 365 69
N6 365 69
N7 365 69
N10 365 68
N13 365 352
N14 365 352
N15 365 195
Poultry
N16 365 352
14 Includes 175 days of full water consumption, and 191 days at 50% water consumption during
milking
53
4.3 Hydraulic ram pumps
4.3.1 Pumps utilising existing river fall
The Environment Agency River Habitat data (1994-1997), and the Flood Studies Report
(NERC, 1974) both include data characterising the hydraulic head (i.e. the difference in elevation, or vertical fall, per unit distance along a river reach). These data are useful to
characterise the magnitude of vertical head which is present – which will constrain the
vertical lift and/or horizontal distance which a hydraulic ram pump could be used to move water from the river source to a different location to provide livestock with drinking water.
Data from the River Habitat surveys reveal that for 82 locations on the River Wensum, the
mean vertical drop was 1.56 m/km river length (range 0.30-10.00; std 1.70). This compares
with the Hampshire Avon which has a mean drop of 2.78 m/km river length (range 0.27-
14.20; std 2.32) based on 248 locations; while the Cumbrian Eden catchment has a mean drop of 14.93 m/km river length (range 0.50-130.00, std 24.80) based on 87 locations. The greater
number of sampling locations in the Hampshire Avon reflects the high ecological sensitivity
of this particular catchment. The high values for the Cumbrian Eden reflect the marked contrast between the steep headwater areas (e.g. to the north and east), and the relatively low
lying valley areas further south. Unsurprisingly, the Wensum in East Anglia has the smallest
mean drop, but (given the low lying relief in this area), even this modest value is sufficient to
provide substantial opportunity for hydraulic ram pumps to be used.
4.3.2 Pumps utilising an artificial fall
This method assumes hydrams can be deployed anywhere along a water body, regardless of
river fall, with a suitable fall achieved by digging in the equipment. This method will still be
constrained by the distance and elevation water can be pumped, with a maximum distance of 1km and elevation of 30m suggested by ADAS experts. Maps with these constraints were
produced as below:
The DTCs were overlaid with a 100 x 100 m points grid, and the elevation of each of the
points extracted from the NEXTMap DEM. The distance between each point and the nearest
river feature point was determined, and all 100 x 100 m grid points ≤1km from a river feature
selected. From this selection of points, the difference in elevation between the nearest river
point and the grid points was calculated. These values were then mapped at a 100 x 100 m
resolution in the bands <0m, 0-10m, 10-20m, 20-30m, and >30m (Figure A4.5).
4.3.3 Livestock grazing areas
Hydrams will need to be installed as close to livestock as possible, so the amount of grazing
land (most likely to be used for livestock) within 1km of water bodies was determined as
below:
The area of managed grassland (ha) was extracted for each 1km2 grid cell in the DTCs from
the ADAS Land Use Database. Cells within 1km of river features were selected, and grouped
into four area categories; 0-25, 25-50, 50-75, and 75-100 hectares. This data was then mapped
at 1km2 to compare the hydram constraints to the amount of grazing land in those regions
(Figure A4.7). The number and percentage of 1km2 cells in each area category was also
calculated for each of the DTCs (Table A4.9; Figure A4.6).
54
Table A4. 8 Amount of managed grassland in cells within 1km of river features
DTC region Area category (ha) Number of cells % of cells
0-25 542 81.1
25-50 112 16.8
50-75 14 2.1
River Wensum
75-100 0 0.0
0-25 710 28.7
25-50 349 14.1
50-75 807 32.6
River Eden and Tributaries
75-100 610 24.6
0-25 757 54.8
25-50 416 30.1
50-75 180 13.0
River Hampshire Avon
75-100 28 2.0
4.4 Solar and wind powered pumps
4.4.1 Solar powered pumps
Solar powered pumps are not greatly limited by daily or annual changes in solar radiation,
and can operate at 400 l/hr in most conditions, so no further analysis is required.
4.4.2 Wind powered pumps
To analyse the how effective wind pumps may be in the DTCs, wind speed data was sourced
from Met Office climate records15, covering a number of weather stations in the UK. Each
site in the database has daily records of wind speed for four 6 hour periods (00, 6, 12, and 18
hours). Data were extracted from the database for records during dates from 01/01/2005 to
31/12/2009, and converted from knots to m/ s. Records were selected that have a windspeed
greater than the threshold of 3m/s. The total number of hours in each day where the wind speed was above the threshold was counted, with each selected record representing 6 hours of
the day. The daily durations were then grouped by month and year, and summed to give the
total number of hours above the threshold for each month of each year. These monthly
durations were averaged across the 5 year period, and the monthly averages summed together
to give an annual duration. The proportion of time in a year where wind speed is greater than
the threshold value was then calculated from the total number of hours in a year. The Met
Office site locations were then mapped, and 5 x 5 km grid cells assigned proportion values from the nearest Met Office site (Figure A4.7).
4.5 Sustainability of catchment abstraction
4.5.1 Holding level data
Water abstraction licences are issued to individual holdings. The numbers of each type of
livestock were used to determine the overall water requirements of each holding.
15 Met Office, 2011
55
4.5.2 Percentage of holdings that require an abstraction license
The location of holdings was mapped, and assigned to 10 x 10 km cells within the DTCs. The
holding level livestock numbers were multiplied by the daily drinking water requirements (Table A4.7). Holdings exceeding a total daily requirement of 20m3 per day (20,000l) were
selected as holdings requiring an abstraction license. The percentage of holdings that would
need a license was then calculated for each 10 x 10 km grid cell in the DTCs.
Maps of the percentage of holdings that require ≥20m3 of water per day for livestock, and
would therefore need an abstraction license under CAMS (Appendix 3) are shown in Figure
A4.8. At a DTC level, this includes 1.63% of holdings in the Wensum DTC, 2.30% in the
Hampshire Avon and 3.09% in the Eden.
4.6 Susceptibility to climate change
4.6.1 Climate projections data
To determine the effect of climate on sustainable water collection and distribution methods,
climate data for was sourced from the UK Climate Projections (UKCP09)16 at a 25 x 25 km
resolution for the 2050s period (average of projections for the years 2040-2069). Data was
selected for a medium emissions scenario (SRES A1B), and a 50% probability17.
4.6.2 Rainwater collection
For rainwater collection during 2050s, the same method was used as for the 1960-1990
baseline data, but with rainfall data from UKCIP09. As the UKCIP data is in a 25 x 25 km rotated grid format, it was overlaid with a 1km2 grid and each grid cell assigned the value of
the 25 x 25 km cell containing its centroid (Figures A4.9a, A4.9b, A4.9c, and A4.9d).
4.6.3 Wind powered pumps
For a medium emissions scenario in England 2050, UKCP09 report that there are likely to be only small changes in wind speed, with a predictions of -0.2 m/ s change for summer, and
near zero for winter, suggesting that under this climate change scenario, wind pumps will not
be significantly affected.
16 http://ukclimateprojections.defra.gov.uk/content/view/12/689/
17 With a 50% probability, the value given is the middle of the range, with 50% of values being higher,
and 50% lower. See http://ukclimateprojections.defra.gov.uk/content/view/1205/618/
56
5 Constraint maps
The maps produced as a result of the GIS analyses for the DTCs are presented below.
5.1 Rainwater harvesting (1961-1990)
57
Figure A4.4a Percentage of water requirements for cattle that can be supplied by rainwater
harvesting during the 1961-1990 baseline climate. Cells are labelled as not applicable where
there are no cattle listed in the 2009 ADAS Land Use Database
58
59
Figure A4.4b Percentage of water requirements for poultry that can be supplied by rainwater
harvesting during the 1961-1990 baseline climate. Cells are labelled as not applicable where there are no poultry listed in the 2009 ADAS Land Use Database
60
61
Figure A4.4c Percentage of water requirements for sheep that can be supplied by rainwater
harvesting during the 1961-1990 baseline climate. Cells are labelled as not applicable where there are no sheep listed in the 2009 ADAS Land Use Database
62
63
Figure A4.4d Percentage of water requirements for pigs that can be supplied by rainwater
harvesting during the 1961-1990 baseline climate. Cells are labelled as not applicable where there are no pigs listed in the 2009 ADAS Land Use Database
64
5.2 Hydraulic ram pumps
65
Figure A4.5 Difference in elevation between 100m grid cells and the nearest river feature, for
cells ≤1km from a river feature (m). Grid cells listed as not applicable are more than 1km
from a river feature
66
67
Figure A4.6 The area of improved grassland listed in cells ≤1km from a river feature, as
listed in the ADAS Land Use Database (ha). Grid cells listed as not applicable are further than 1km from river features
68
5.3 Wind powered pumps
69
Figure A4.7 Proportion of time in the year where wind speed is ≥3m/s
70
5.4 Water abstraction
71
Figure A4.8 Percentage of holdings in 10 x 10km grid cells that require more than 20m3 of
water per day for livestock drinking water. Grid cells listed as not applicable do not have any
livestock data reported in the Defra 2009 census
72
5.5 Rainwater harvesting (2050s)
73
Figure A4.9a. Percentage of water requirements for cattle that can be supplied by rainwater
harvesting during a projected 2050’s climate. Cells are labelled as not applicable where there
are no cattle listed in the 2009 ADAS Land Use Database
74
75
Figure A4.9b. Percentage of water requirements for poultry that can be supplied by rainwater
harvesting during a projected 2050’s climate. Cells are labelled as not applicable where there are no poultry listed in the 2009 ADAS Land Use Database
76
77
Figure A4.9c. Percentage of water requirements for sheep that can be supplied by rainwater
harvesting during a projected 2050’s climate. Cells are labelled as not applicable where there are no sheep listed in the 2009 ADAS Land Use Database
78
79
Figure A4.9d. Percentage of water requirements for pigs that can be supplied by rainwater
harvesting during a projected 2050’s climate. Cells are labelled as not applicable where there are no pigs listed in the 2009 ADAS Land Use Database
