View
3
Download
0
Category
Preview:
Citation preview
Page 1
Pepin Marsh 1. Location: Aldergrove Lake Regional Park. Langley Township, B.C.
2. Construction Timeline: June 2013 - April 2014Construction Timeline
Construction Stage Timing Detail
Control of Invasive SpeciesInitial Control June 2013 Field preparation: mowing as soon as field is accessible to tractor
Initial Control July 2013 Apply glyphosate using tractor boom in late summer to resprouting grass (approx. 12” height). (requires dry watercourses)
Seed bank exhaustion Aug 2013 Tilling / harrowing at least 3 times in summer 2013. Potential for secondary glyphosate application in early August prior to construction
Habitat Complexing and Feature Construction Habitat complexing Aug – Sep 2013 Sculpt landscape: channels, pools, benches.
Feature construction Sep 2013 Install ponds, weirs, large wood; construct trails.
Hydrologic restorationHabitat complexing Sep 2013 Infill ditches, plug drain tile, water flow and water control devices.
Feature construction Sep 2013 Connect habitat complex to groundwater; monitor and adjust as necessary.
Re-vegetationInitial Seeding Oct 2013 Seed with native wetland seeds.
Shrub planting Oct - Nov 2013 Plant riparian / higher elevation berms / islands / trails.
Herb planting March - April 2014 Plant plugs in depressions. Spread additional seed.
Project SummaryFebruary 18, 2013
Page 2
3. Goals
The goals of this project are, through the recreation of a shallow-water marsh wetland habitat on historic agricultural fields, to:a) Provide recovery habitat for the endangered Oregon spotted frog; b) Enhance general wildlife biodiversity, with a particular focus on Species-at-Risk; c) Provide education, stewardship and research opportunities in wetland restoration and species recovery; andd) Increase our knowledge of marsh restoration techniques.
4. Current Site Condition:
Constructed drainage channels
0 Ave
A
C
B
A
C
B
Page 3
5. Grading Plan
Drainagetiles plugged
Backup water source
Backup watersource
Primary groundwatersource EL 42.25
stone weir control point
Primary groundwater source EL 43.65
Primary groundwater source EL 43.65
Drainagetiles plugged
44.4
44.8
45.2
45.6
44.8
44.644.4
45.0
45.2
44.2
44.0
44.2
43.843.6
43.6
43.8
43.6
43.8
44.044.2
44.043.843.643.443.2 43.042.8
42.6
43.6
42.643.043.243.4
43.4
43.0
43.6
43.8
44.0
43.043.6
43.043.643.8
43.2
43.4
43.0
43.6
43.8
42.6
43.8
43.4
43.0
44.0
44.044.043.8
43.643.042.6 43.0
43.8
43.8
43.0
44.6
45.0
45.4
44.2
44.4
44.2
44.4
44.043.8
44.2
44.4
45.2
43.4
43.443.6
43.844.044.2
43.843.6
44.0
43.643.844.044.244.4
44.2
44.4
44.6
44.644.845.045.245.4
44.6
44.8
44.444
.244.0
43.843.6
43.6
44.2
43.6
Ditch plugged
44.2
44.244.4
44.6
44.6
44.6
44.0
44.6
43.443.6
43.2
43.8
43.8
43.843.643.443.2
44.044.2
44.444.6
44.845.0
45.245.445.6
45.846.0
44.6
Backup watersource
43.8
43.8
+hp 44.3
+hp 43.9
+hp 43.9
43.6
43.8
43.844.044.244.4
+hp 44.5
43.6
43.6
43.643.443.2
43.8
+hp 44.0
+hp 44.2
44.0+hp 44.1
44.4
44.4+hp 44.5
44.244.043.8
43.6
Existing trail
+hp 43.7
43.8
43.6
43.443.243.042.8
LEGEND
Minimal water depth at 25cm
Medium water depth at 40cm
Maximum water depth North pool at 70cmSouth pool at 135cm
Fill relocated from excavation (major massing shown)
Trail system
Proposed Lookout point
Potential location for pipe leading from backup water source
0 5 2010 40 60
PEPIN MARSH GRADING PLAN
Pool bottom at EL 42.25EL 42.5 at 25cm depth (minimal depth)EL 42.65 at 40cm depth (medium depth)
EL 43.6 at 135cm depth (maximum depth)
Pathway at EL 44.5
SOUTH POOL
Pool bottom at EL 43.65EL 43.9 at 25cm depth (minimal depth)
EL 44.05 at 40cm depth (medium depth)
NORTH POOL
SAMPLE SECTION
Page 4
Drainagetiles plugged
Backup water source
Backup watersource
Primary groundwatersource EL 42.25
stone weir control point
Primary groundwater source EL 43.65
Primary groundwater source EL 43.65
Drainagetiles plugged
44.4
44.8
45.2
45.6
44.8
44.6
44.445.0
45.2
44.2
44.0
44.2
43.843.6
43.6
43.8
43.6
43.8
44.044.2
44.043.843.643.443.2 43.042.8
42.6
43.6
42.643.043.243.4
43.4
43.0
43.6
43.8
44.0
43.043.6
43.043.643.8
43.2
43.4
43.0
43.6
43.8
42.6
43.8
43.4
43.0
44.0
44.044.043.8
43.643.042.6 43.0
43.8
43.8
43.0
44.6
45.0
45.4
44.2
44.4
44.2
44.4
44.043.8
44.2
44.4
45.2
43.4
43.443.6
43.844.044.2
43.843.6
44.0
43.643.844.044.244.4
44.2
44.4
44.6
44.644.845.045.245.4
44.6
44.8
44.444
.244.0
43.843.6
43.6
44.2
43.6
Ditch plugged
44.2
44.244.4
44.6
44.6
44.6
44.0
44.6
43.443.6
43.2
43.8
43.8
43.843.643.443.2
44.044.2
44.444.6
44.845.0
45.245.445.6
45.846.0
44.6
Backup watersource
43.843.8
+hp 44.3
+hp 43.9
+hp 43.9
43.6
43.8
43.844.044.244.4
+hp 44.5
43.6
43.6
43.643.443.2
43.8
+hp 44.0
+hp 44.2
44.0+hp 44.1
44.4
44.4+hp 44.5
44.244.043.8
43.6
Existing trail
+hp 43.743
.8
43.6
43.443.243.042.8
LEGEND
Minimal water depth at 25cm
Medium water depth at 40cm
Maximum water depth North pool at 70cmSouth pool at 135cm
Fill relocated from excavation (major massing shown)
Trail system
Proposed Lookout point
Potential location for pipe leading from backup water source
0 5 2010 40 60
PEPIN MARSH GRADING PLAN
Pool bottom at EL 42.25EL 42.5 at 25cm depth (minimal depth)EL 42.65 at 40cm depth (medium depth)
EL 43.6 at 135cm depth (maximum depth)
Pathway at EL 44.5
SOUTH POOL
Pool bottom at EL 43.65EL 43.9 at 25cm depth (minimal depth)
EL 44.05 at 40cm depth (medium depth)
NORTH POOL
SAMPLE SECTION
Ephemeral channel
Page 5
6. Monitoring Program
7. Adaptive Management Plan
Monitoring Program
Hydrological Regime Re-vegetationHabitat
FeaturesWildlife
PresencePermanent ponds Wet Meadow Permanent
ponds Wet Meadow
Methods Water gauges in ponds
Water depth at transect points and in ground-water wells
Visual surveys & vegetation plots
Visual surveys & permanent vegetation plots along transects
Habitat plots at designed feature sites
Wildlife surveys: visual, audi-tory and trapping
Targets Max 40 cm in June - July; Min 25 cm in Aug / Sept.
Fields flooded during winter & OSF breeding season.
Native: invasive plant species ratios
Native: invasive plant species ratios
Substrate and vegetation structure; water depth etc.
Native and invasive amphib-ians; native birds; native and invasive fish.
Potential outcomes:
1. As per design2. Wetter than design3. Drier than design
A. Preferred outcomeB. Acceptable outcomeC. Undesirable outcome
i. Confidence in breeding / overwintering habitat suitability.
ii. Non-confidence in habitat suitability for OSF.
a. Low density of bullfrog adults and invasive fish.
b. High density of bullfrog adults and breeding on-site; invasive fish species.
Mgmt questions addressed
Hydrologic changes needed: in-crease / decrease input or outflow.
Invasive species management methods: chemical or manual / patch-treatment or landscape-level.
Likelihood of success for Ore-gon spotted frog introduction.
Likelihood of success for Ore-gon spotted frog introduction.
PEPIN MARSH
1A: Patch reed canary grass re-moval. Manual and chemical as needed.
Add native plants and re-seed if available.
3A: Increase outlet height.
Avoid connection to Gordon’s brook to reduce risk of reed canary grass re-establish-ment.
2A: Reduce outlet height.
If necessary divert some flow to remnant ditchs or Gor-don’s Brook.
1C:Annual mowing of ephemeral marsh in late summer.
Patch reed canary grass treat-ment in ponds. ‘Grass-break-ers” volunteer events. Invasive plant excavation if available.
3C: a. Largescale mow and reed
canary grass treatment / spray in late summer*.
b. Increase outlet height.
(*budget-dependent)
2C: Reduce outlet height.
If necessary divert some flow to remnant ditchs or Gor-don’s Brook.
1B: Annual mowing of ephemer-
al wetland in late summer.
Add native plants and re-seed if available.
3B: Increase outlet height.
If necessary, connect to Gordon’s Brook for additional water source.
2B: Reduce outlet height.
If necessary divert some flow to remnant ditchs or Gor-don’s Brook.
Post-construction vegetation establishmentA: Preferred outcome• Widespread native plant
growth. • Patchy reed canary grass
growth.
B: Acceptable outcome• Widespread reed canary grass
in ephemeral marsh. • Ponds primarily populated
with native emergent species.
C: Undesirable outcome• Widespread reed canary grass
in ephemeral marsh.• Widespread grass in / around
ponds. Few native species.
Post
-con
stru
ction
hyd
rolo
gic
regi
me
2. Wetter than design:
• Ephemeral marsh stays wetted throughout year.
• Ponds > 40 cm deep in summer.
1. As per design:
• Ephemeral marsh floods Oct - June. Dries out mid- late summer.
• Ponds retain permanent water.
3. Drier than design:
• Ephemeral marsh dries in early spring.
• Ponds dry in late sum-mer.
Potential Futures &Adaptive Management Plan
PEPIN MARSH
Introduce Oregon Spotted
Frogs if suitable habitat features +
low-density bullfrogs
Recommended