Design Templates F4.1 Infrastructure Technical Stormwater ... · Design Templates Worksheet 6 Detention Tank Design W4.6 Infrastructure Technical Specifications . 𝑄= 𝐶𝐴√2𝑔ℎ

Design Templates Stormwater Calculation Summary

F4.1 Infrastructure Technical Specifications

Site Address:

Consent Number:

Application by:

Total Site Area Prior to Subdivision

Lot 1 Area

Lot 2 Area

Lot 1 C

Lot 2 C Design Storm Details

ARI

Soakage Viable Yes/No

Lot 1

Provide

number 900 mm soakholes

or

metres of 1.0 m*1.5 m*1.5 m rock filled soak trench

or

metres of 1.0 m*1.5 m*1.2 m proprietary trench

proprietary units

Lot 2

Provide

number 900 mm soakholes

or

metres of 1.0 m*1.5 m*1.5 m rock filled soak trench

or

metres of 1.0 m*1.5 m*1.2 m proprietary trench

proprietary units

Detention

Allowable runoff flow rate into HCC reticulation

litres/second

Lot 1 Share

%

Lot 2 Share

%

l/s

l/s

Lot 1 provide

Lot 2 provide minimum

litres detention

minimum

litres detention

orifice

mm diameter

orifice

mm diameter

Version: October 2012 Page 1 of 1

Design Templates

Worksheet 1 Falling Head Percolation Test


Site Address:

Completed by: Date:

Qualification: Chartered Engineer Civil Engineer Engineering Technician Engineering Geologist Drain Layer Other _________________ Registration number ___________________ (tick one)

Date of test: Season:

The following procedure has been carried out

Hole kept full for 17 hrs. prior to test Hole kept full for 4 hrs. prior to test

Drop in water level recorded at intervals of 30 mins (or less)

Test continued for 4 hrs. Test continued until bore empty

Test stopped at 0.25 m above base Hole refilled at 0.25 m above base

(tick when complete) Signature:

Test Details

Bore hole reference ref:

Diameter of bore D= ____.____ mm

Depth of bore ____.____ mm

Time (min) Depth (mm) Time (min) Depth (mm)

Calculations

Soakage Rate Sr = Minimum Gradient * = 𝑌

𝑋

*a straight line interpolation between last points on graph 𝑦/𝑥 = = ____________mm/hr

Divide by 1000 for m/hr ____________m/hr


Design Templates

Worksheet 2 Falling Head Percolation Graph


Site Address:

Completed by: Date:

Bore ref:

1 2 3 4 0

2000

3000

1000

Wat

er D

epth

(mm

)

Time (hr)


Design Templates

Worksheet 3 Stormwater Runoff Calculation Summary – 2 Lot Development


Site Address:

Completed by: Date:

Pre-Development Site Runoff

Zone Residential Industrial Commercial

5 min storm intensity 2 year 5 year 10 year

Pre-climate Change I= _____ mm/hr _____ mm/hr _____ mm/hr

Total Site Area A= ________m2

Allowable Runoff From Site 𝑄 = 𝐶𝐼𝐴3600000

m3/s

Qallow= ____𝑋____𝑋____3,600,000

=

_______________m3/s

Note: litres/second = [(m3/s)*1000] [_______________l/s]

Developed site Lot 1


1 hr storm intensity _____ year _______ year _______ year

Post-climate Change I= _____ mm/hr _____ mm/hr _____ mm/hr

Lot 1 Area Alot1= ______________ m2

Equivalent Impervious Area

Cover Type Area (m2) Coefficient C Area x C

Roof Ar = 0.95

Paved Apv = 0.95

Pervious (lawn etc.) Ape = 0.3

Ae = ∑(𝐴𝑟𝑒𝑎 𝑥 𝐶)

Equivalent Runoff Coefficient Ceqv = 𝐴𝑒𝐴𝑙𝑜𝑡1

=

Runoff From Site𝑄 = 𝐶𝑒𝑞𝑣𝐼𝐴𝑙𝑜𝑡13600000

m3/s

Qlot1= ____𝑋____𝑋____3,600,000

=

_______________m3/s



Design Templates

Worksheet 3 Stormwater Runoff Calculation Summary – 2 Lot Development


Developed site Lot 2 Run-off


____ min storm intensity _____ year _______ year _______ year

Value from manual I= _____ mm/hr _____ mm/hr _____ mm/hr

Lot 2 Area Alot2= ______________ m2

Equivalent Impervious Area

Cover Type Area (m2) Coefficient C Area x C

Roof Ar = 0.95

Paved Apv = 0.95

Pervious (lawn etc.) Ape = 0.3

Ae = ∑(𝐴𝑟𝑒𝑎 𝑥 𝐶)

Equivalent Runoff Coefficient Ceqv = 𝐴𝑒𝐴𝑙𝑜𝑡2

=

Runoff From Site𝑄 = 𝐶𝑒𝑞𝑣𝐼𝐴𝑙𝑜𝑡23600000

m3/s

Qlot2= ____𝑋____𝑋____3,600,000

=

_______________m3/s



Design Templates

Worksheet 4 Nominal Soakage Design


Site Address:

Completed by: Date:

Area of additional impervious surface _____ m2

Note this needs to be <= 20 m2

Describe the general soil type [excavate a 1.0 m square hole, 1.0 m deep in the general area of the proposed soak pit]

Fill the hole with water

Does the water soak away within 24 hours? Yes – Use nominal soak pit as detail available from the City Development Unit No – alternative method of disposal possibly required – refer to designer.


Design Templates

Worksheet 5 Soakage Design


Site Address:

Completed by: Date:

Area for lot number ___ from worksheet 3 Alot__ _____ m2

Equivalent Runoff Coefficient from worksheet 3 Ceqv

Soakage Rate (from worksheet 1) Sr _____ m/hr

Design storm

Duration I mm/hr

Depth (d) mm Q=CIequivAlot_/3600000 m3/s

Volume in Vin=(d/1000) x A m3

5 min

10 min

20 min

30 min

60 min – 1 hr

2 hr

6 hr

12 hr

24 hr

48 hr

72 hr

Note for soakage design initially use a one hour storm duration

Rainfall Runoff Volume 𝑅𝑐 = 10 𝑥 𝐶𝑒𝑞𝑖𝑣 𝑥 𝐼 𝑥 𝐴𝑙𝑜𝑡10000

= 10 x ___ x ___ x ___

Rc = _____m3

For a typical soakhole 900 mm diameter

Volume of runoff disposed of by 𝑉𝑠𝑜𝑎𝑘 = 𝐴𝑠 𝑥 𝑆𝑟 𝑥 𝑆𝑑


Design Templates



soakage

𝐴𝑠 = 𝑆𝑜𝑎𝑘𝑎𝑔𝑒 𝐴𝑟𝑒𝑎

(for one 900 mm dia soakhole) = 0.636 m2

𝑆𝑟 = 𝑆𝑜𝑎𝑘𝑎𝑔𝑒 𝑅𝑎𝑡𝑒

____ m/hr

𝑆𝑑 = 𝑆𝑡𝑜𝑟𝑚 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛

1 hr

𝑉𝑠𝑜𝑎𝑘 = 0.636 𝑥 _____𝑥1 _______m3

Volume of runoff held in storage 𝑉𝑠𝑡𝑜𝑟𝑒 = 𝐴𝑠 𝑥 𝐷𝑠 𝑥 𝑉𝑟𝑓


(for on 900 mm dia soakhole) = 0.636 m2

𝐷𝑠 = 𝐷𝑒𝑝𝑡ℎ 𝑜𝑓 𝑠𝑡𝑜𝑟𝑎𝑔𝑒 (ground water depth – 0.5 m or depth of soakhole - 0.5 m) Keep to 2.0 m max depth)

____m

𝑉𝑟𝑓 = 𝑉𝑜𝑙𝑢𝑚𝑒 𝑅𝑒𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑓𝑎𝑐𝑡𝑜𝑟

0.38 for rock filled hole

𝑉𝑠𝑡𝑜𝑟𝑒 = 0.636 𝑥 __𝑥 0.38 _______m3

For 1 Soakhole Capacity = 𝑉𝑠𝑜𝑎𝑘 + 𝑉𝑠𝑡𝑜𝑟𝑒 _______m3

For the site Soakholes required - 𝑉𝑠𝑜𝑎𝑘 + 𝑉𝑠𝑡𝑜𝑟𝑒 > 𝑅𝑐

Therefore 𝑅𝑐𝑉𝑠𝑜𝑎𝑘+𝑉𝑠𝑡𝑜𝑟𝑒

=

_________ Soakholes


Design Templates



For a typical soak trench (1.0 m wide by 1.5 m long)

Volume of runoff disposed of by soakage

𝑉𝑠𝑜𝑎𝑘 = 𝐴𝑠 𝑥 𝑆𝑟 𝑥 𝑆𝑑


(1.0 m * 1.5 m) = 1.5 m2


____ m/hr

𝑆𝑑 = 𝑆𝑡𝑜𝑟𝑚 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛

1 hr

𝑉𝑠𝑜𝑎𝑘 = 0.636 𝑥 _____𝑥1 _______m3



(1.0 m * 1.5 m) = 1.5 m2

𝐷𝑠 = 𝐷𝑒𝑝𝑡ℎ 𝑜𝑓 𝑠𝑡𝑜𝑟𝑎𝑔𝑒 (ground water depth – 0.5 m or depth of trench - 0.5 m) Keep to 2.0 m max depth)

____m


0.38 for rock filled hole

𝑉𝑠𝑡𝑜𝑟𝑒 = 0.636 𝑥 __𝑥 0.38 _______m3

For 1 trench Capacity = 𝑉𝑠𝑜𝑎𝑘 + 𝑉𝑠𝑡𝑜𝑟𝑒 _______m3

For the site Metre of trench required - 𝑉𝑠𝑜𝑎𝑘 + 𝑉𝑠𝑡𝑜𝑟𝑒 > 𝑅𝑐


=

_________ m

For proprietary system (dimensions and void figures from manufacturer) (use a 1.0 m length)

Volume of runoff disposed of by soakage

𝑉𝑠𝑜𝑎𝑘 = 𝐴𝑠 𝑥 𝑆𝑟 𝑥 𝑆𝑑


= __________m2


____ m/hr

𝑆𝑑 = 𝑆𝑡𝑜𝑟𝑚 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛 1 hr


Design Templates



𝑉𝑠𝑜𝑎𝑘 = _____ 𝑥 _____𝑥1 _______m3



______m2

𝐷𝑠 = 𝐷𝑒𝑝𝑡ℎ 𝑜𝑓 𝑠𝑡𝑜𝑟𝑎𝑔𝑒 (ground water depth – 0.5 m or depth of unit - 0.5 m) Keep to 2.0 m max depth)

____m


0.__________

𝑉𝑠𝑡𝑜𝑟𝑒 = ______ 𝑥 _____𝑥 _____ _______m3

For 1 trench Capacity = 𝑉𝑠𝑜𝑎𝑘 + 𝑉𝑠𝑡𝑜𝑟𝑒 _______m3

For the site Metre of product required - 𝑉𝑠𝑜𝑎𝑘 + 𝑉𝑠𝑡𝑜𝑟𝑒 > 𝑅𝑐


=

_________ m

Summary of Calculations Soakhole ____m deep = ______ Soakholes 1.0 m x 1.5 m Soak trench _____deep = ______ metres of trench Proprietary system ______ deep = ______ metres of product


Design Templates

Worksheet 6 Detention Tank Design

W4.6 Infrastructure Technical Specifications

Site Address:

Completed by: Date:

Area for lot number ___ from worksheet 3 Alot__ _____ m2

Equivalent Runoff Coefficient from worksheet 3 Ceqv

Soakage Rate (from worksheet 1) Sr _____ m/hr

Design storm

Duration I mm/hr

Depth (d) mm

Q=CIequivAl

ot_/

3600000 m3/s

Volume in Vin=(d/

1000) x A m3

Volume Out Vout = Qallow x

duration in secs m3

Volume store

Vin – Vout

m3

5min

10min

20min

30min

60min

2hr

6hr

12hr

24hr

48hr

72hr

Select the largest volume store value and provide at least this sized detention tank. Orifice Plate Design

1. Determine the size and dimensions of the proposed detention tank. 2. Based on the tank dimensions, calculate the height (h) of detained stormwater above the location of the orifice

outlet. 3. Calculate the size of the orifice required for the detention tank from the following formula:


Design Templates

Worksheet 6 Detention Tank Design


𝑄 = 𝐶𝐴√2𝑔ℎ

Where Q= allowable flow into HCC reticulation C= 0.98 [orifice coefficient] A=area of orifice g=acceleration due to gravity h=height of water above orifice opening

Therefore area of orifice required 𝐴 = 𝑄𝐶√2𝑔ℎ

And for a round drilled hole the diameter (D) of orifice required is calculated by 𝐴 = 𝜋𝑟2 thus 𝑟 = √𝐴

𝜋 and 𝐷 = 2𝑟

Where D= diameter of circle r = radius of circle 𝜋 = 𝑃𝐼 A = area of orifice


Design Templates

Worksheet 7 Combined Detention / Retention Tank

Design


Site Address:

Completed by:

For single dwellings detention tanks shall provide a minimum of _______ storage for re-use and the volume determined above for detention.

For multi-unit development detention tanks shall provide a minimum of _______ storage for re-use and the volume determined above for detention.


Inspection Templates

Wetlands and Ponds Checklist F4.8

Infrastructure Technical Specifications Location: ________________________________________________________________________________________

Developer Council Comments Tick if correct Tick if correct

Administration Details

Developer name and contact details

Detention facility location – street address

Detention facility type (wetland, dry detention basin)

NZ map reference

Site plan No

Resource consent number (HCC and WRC)

Catchment name

Contributing catchment area

Coordinates for detention facility centre

Levels Levels to LINZ datum

Top of dam (RL)

Top of spillway (RL)

Toe of dam (RL)

2 yr ARI water level 10 yr ARI water level 100 yr ARI water level

Dimensions

Max pond length

Max pond width

Height of dam in metres to 0.1 m

Approx. max water depth to 0.1 m

Normal water depth to 0.1 m

Operating surface area (m2)

Normal storage volume (m3)

Spillway details Type Width or diameter

Inlet details Type Width or diameter

Outlet details Type Width or diameter

Flow Design 2 yr return period design m3/s 10 yr storm controlled at high level weir (m3/s) 100 yr storm at spillway (m3/s) Sediment Treatment Estimated suspended solids removal %

Estimated sediment accumulation rate in tonnes/year



Wetlands and Ponds Checklist F4.8

Infrastructure Technical Specifications

Developer Council Comments

Tick if correct Tick if correct

Safety Features

Planting details Date of planting Plants source Maintenance Requirements Methodology for the on-going and long-term maintenance Estimated cleaning frequency in years

• Forebay • Main pond

Details for permanently wet areas Details for surrounding areas How facility should be dewatered and desilted Attachments Location map Legal description of site Detailed scale plan of total contributing catchment Construction detail plans of the pond including all structures

Approved As-built plan showing truck maintenance access, working and storage areas

WRC resource consent Geotechnical report if applicable Design calculations As-built planting plan Consent compliance reports from WRC All information included in required format

Further information required

…………………………………………….. …………………………………………….. Developer Council …………………………………………….. …………………………………………….. Date Date



Wetland and Ponds Inspection/Signoff Checklist


For completion by Developer prior to requesting:

1. 224c approval 2. First defects liability inspection 3. Final defects liability inspection 4. Remedial works completion inspection

Location: _________________________________________________________________________________________

Plan No. : __________________________

Date

Date Date Date

Type of Inspection (record 1,2,3 or 4)

Tick if satisfactory Tick if satisfactory Tick if satisfactory Tick if satisfactory

Pre-inspection 1) Final as-built plans sent to Council 2) Checklists completed for all pipelines and manholes 3) Planting Plan approved by Council Site Meeting 1) Forebay accessible and has all weather access 2) Forebay clear of sludge 3) Boundary pegs sighted 4) Works align with as built plans 5) Spillway/s clear of obstruction 6) Erosion and soil stability 7) Inlet and outlet has structural integrity 8) Plants at least 2.0 m clear of inlet and outlet 9) Planting done to approved planting plan 10) Plant density (approx. 1 per m2) 11) Plants in good condition 12) No plant pests 13) Weed (%) compliant with ITS 14) No notifiable weeds 15) Plants sourced from Waikato Ecological District

16) Safety Features All works satisfactory Remedial work required ………………………………….. …………………………………. Developer Council Date ……………………………

Date…………………………….


Quality Assurance Design Certificate

F4.10 Infrastructure Technical Specifications WATER/WASTEWATER/STORMWATER – QUALITY ASSURANCE DESIGN CERTIFICATE

Site Address/Project Name

Consent Number if known

Name of Designer

Designers relevant qualifications

I hereby confirm that the design of the water reticulation / wastewater provision / Stormwater provision for the above site has been designed in accordance with the following standard _________________________________

Engineering Exception Decisions

The following aspects of the design do not meet the requirements of the above standard. (Where standards are not met, please detail the alternative standard achieved).

Accepted Y N

Signed: Date:

Version : October 2012 Page 1 of 1

Pipe Laying Checklist F4.11 Infrastructure Technical

Specifications WASTEWATER PIPE LAYING CHECKLIST

Location:

to

to

to

to

to

Pipe Laying Checks Pipe length (MH To MH)

• Trench Safety (a) Shield (b) Batter (c) Other

• Pipe size, quality, approved materials confirmed

• Set out checked • Surveyors name ________________ • Control points identified

• Foundation support • penetrometer results available • if under cutting required, note

chainage and CBR results.

• Record daily level check and confirm on grade

• Bedding type and surround material _______________________________

• Bulk Backfill material _______________________________

• Bulk backfill compaction (CBR results from pipe to ground level attached)

• Alignment – control points identified

Service connections

• All service connections in place, taped and staked

• Connections correctly located horizontally and vertically

• Connections to main correctly formed

• As-built measurements taken

• CCTV pipe inspection

________________________________________ ________________________________________

Developer Date

Version : October 2012 Page 1 of 1 For further information about this form, email [email protected]

mailto:[email protected]

Manhole Checklist F4.12 Infrastructure Technical

Specifications MANHOLE CHECKLIST

Location:

to

to

to

to

to

Manhole Construction Checklist

MH number

• Manhole size, quality, approved materials checked

• Set out /orientation

• Sealing strip between risers

• Benching • Height • alignment and cross section • half pipe lining (wastewater only) • Step recesses (if applicable)

• Flexible joints

• Cutting and plastering of connections

• Access details per drawings

• Step irons including epoxy to outside recesses

• Bedding type and surround

• Bulk backfill compaction (CBR results attached)

• No debris in pipelines

• Invert of pipes in and out

________________________________________ ________________________________________

Developer Date



Trench Backfill Compaction Test

Summary Checklist

F4.13 Infrastructure Technical Specifications TRENCH BACKFILL COMPACTION TEST SUMMARY (attach individual test reports)

Location: __________________________________________________________________________________

Plan No: __________________________________________________________________________________

From MH ______________________________ to MH ___________________________________

Acceptance Criteria: _______________________________________________________________________

Tests by: ______________________________________________________________ (attached)

Analysis of Results

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

Trench backfill completed satisfactorily

Trench backfill requires remedial work

________________________________________ ________________________________________

Developer Date

Version: October 2012 Page 1 of 1 For further information about this form, email [email protected]


Stormwater and Wastewater

Catchpit Checklist Checklist

F4.14 Infrastructure Technical Specifications CATCHPIT CHECKLIST

Location:

Catchpit Construction Checklist

Catchpit Number

• Catchpit , type, size, quality, approved material checked

• Set out /orientation

• Location checked

• Depth of sump below outlet correct

• Cutting and plastering of outlet connection

• Floating debris baffle installed correctly

• Backfill compaction around pit checked

• Seating and plastering of surround and grate to sump barrel

• All silt and debris removed from sump

________________________________________ ________________________________________

Developer Date



Final Inspection Pipe Network Checklist F4.15 Infrastructure Technical

Specifications FINAL INSPECTION FOR STORMWATER AND WASTEWATER NETWORKS

Location: _________________________________________ Plan No: _________________________

Pre-Meeting Tasks

Developer Checklist Council Pass Developer to verify prior to meeting: SW WW

1. All checklists completed

2. All lines flushed out 3. All required CCTV inspections carried out, reviewed and any re-work

completed.

4. All manholes checked (eg.infiltration, plastering)

5. Catchpits checked

6. All backfilling complete and tidied up

7. Pressure test completed and witnessed

8. Final as-built plans attached for approval

9. Inspection arranged with Council

Site Meeting

1. Inspect all lines

2. Inspect all manholes and catchpits

3. All manholes and catchpits set to level

4. Inspect SW inlet and outlet structures

5. Secondary flowpaths and detention ponds

6. Works on third party land completed to satisfaction of owner

7. Wastewater pumping station

8. Overland flow from adjoining properties not effected

9. All works satisfactorily

10. Remedial work required ________________________________________ ________________________________________

Developer Council

________________________________________ ________________________________________

Date Date



Documents

Design Templates F4.1 Infrastructure Technical Stormwater ... · Design Templates Worksheet 6 Detention Tank Design W4.6 Infrastructure Technical Specifications . 𝑄= 𝐶𝐴√2𝑔ℎ