Wetland Rehabilitation in a Reservoir Setting Wetland Habitat Enhancement: U.S. 95 Sand Creek Byway Josh Butler & Gretchen Herron CH2M HILL Inc.

Transcription

1 Wetland Rehabilitation in a Reservoir Setting Wetland Habitat Enhancement: U.S. 95 Sand Creek Byway & Gretchen Herron CH2M HILL Inc., Boise, Idaho

2 CONTENTS 1. Background & Design Basis 2. Construction 3. Wetland Performance Monitoring 4. Summary & Conclusions

3 1.0 Project Background & Design Basis U.S. 95 Sand Creek Byway Idaho Transportation Department (ITD, District 1) Constructed Roughly 3.5 km (2.2 miles) of new U.S. 95 and Bike/Pedestrian Path Roughly 2 km (1.2 miles) of New Shoreline Habitat Along Sand Creek Alignment is on a natural terrace between Lake Pend Oreille and Sand Creek; annual fluctuation in lake level of 2-4 m Roadway geometrically constrained between Sand Creek and BNSF/UPRR Railways 4 Bridges (up to 316 m span) 16 Retaining Walls (up to 9 m in height)

4 1.0 Project Background & Design Basis 2 km of Enhanced Shoreline Habitat Along Sand Creek Existing U.S. 95 (blue & red) Sand Creek Proposed U.S. 95 (yellow) Lake Pend Oreille

5 1.0 Project Background & Design Basis

6 1.0 Project Background & Design Basis Pathway Habitat Enhancement Plan Problems & Challenges Perception/Aesthetic Access Function Ecosystem Constructed acres of Habitat Enhancement Adjacent to Bike/Pedestrian Path Aesthetic Appeal for the Citizens of Sandpoint Introduce Variability That Works with Albeni Falls Dam/Lake Pend Oreille Hydraulic Regime Wetland Sod, Trees/Shrubs, Uplands & Wetlands Significant Public involvement

7 1.0 Project Background & Design Basis Albeni Falls Dam: Typical Operating Conditions, Lake Pend Oreille m m

8 1.0 Project Background & Design Basis

9 1.0 Project Background & Design Basis

10 1.0 Project Background & Design Basis

11 1.0 Project Background & Design Basis Design Challenges: Cost vs. Results >3 acres of surface area How protect from erosion? Scour? Design Solution: Rock toe Wetland Sod Biotechnical Elements (brushlayer, brush mattress, live fascine, etc.) Upland Sod, Seeding, Trees, Shrubs Mix It Up!

12 1.0 Project Background & Design Basis Design Challenges: Cost vs. Results TABLE 1 Vegetative Alternatives Costs Costs Presented in Units of Dollars per Square Meter Alternatives: Pretreatment with seeding Bareroot Plants Containerized Plants SMS Wild Transplants Wetland Sod Plant Materials and $4.31 $37.78 $ $9.36 $26.26 $38.00 Direct Costs 1 Indirect Costs 2 $4.77 $11.30 $11.30 $11.42 $11.45 $0 5 Topsoil 3 $10.55 $10.55 $10.55 $2.58 $2.58 $2.58 Total $19.63 $59.63 $56.51 $23.36 $40.29 $40.58 Anticipated Success in PHEP Wetland Areas Failure Poor Good Poor Good Very Good 1 Includes plants, handling & delivery, and installation costs. 2 Includes erosion control blanket, seed bed prep, mulching, tackifier (mulch anchoring), fertilizing, bonded fiber matrix, herbivore protection, weed control, and replanting costs. 3 Assumes 300-millimeter topsoil thickness for wetland areas; 76 mm is used for SMS, wild transplants, & wetland sod. 4 Assumes 3,800 cubic centimeter plants (1 gallon), on 0.45-meter centers. 5 Handling and delivery is waived for large orders.

13 2.0 Construction PHEP Construction: Elevation Ranges Species From To Species Types Within Elevation Range: Deschampsia caespitosa (Tufted Hairgrass), Juncus balticus (Baltic Rush). DeJb CnCuJb ClCnCu Overseeded with mix of equal parts of Beckmannia syzigachne (Sloughgrass) and Calamagrostis canadensis (Bluejoint). Carex nebraskensis (Nebraska sedge), Carex utriculata (rostrata) (Beaked sedge), and Juncus balticus (Baltic rush). Carex lanuginosa (Wooly sedge), Carex nebrascensis (Nebraska sedge), and Carex utriculata (rostrata) (Beaked sedge). Sa, Sm Schoenoplectus (Scirpus) acutus (Hardstem bulrush), Scirpus microcarpus (Panicled bulrush).

14 2.0 Construction Wetland Sod: Planted in 2010, 2011

15 2.0 Construction Wetland Sod: Planted in 2010, 2011

16 2.0 Construction Timing is KEY! (Advanced Order, Hydrologic Timing) m?!?

17 2.0 Construction Timing is KEY! (Advanced Order, Hydrologic Timing)

18 3.0 Wetlands Performance Monitoring Wetlands Monitoring Performed by: Gretchen Herron (2012, 2013, 2014) Judy Ferguson/CH2M HILL (2011, 2012) USACE Performance Criteria: PSS-PFO PEM Upland Buffers Vegetative Cover [Native] Species Diversity Limit Invasive Species Common Tansy (Tanacetum vulgare), Canada Thistle (Cirsium arvense), Reed Canarygrass (Phalaris arundinacea), and Dalmation Toadflax (Linaria genistifolia)

19 3.0 Wetlands Performance Monitoring April 2010

20 3.0 Wetlands Performance Monitoring August 2010

21 3.0 Wetlands Performance Monitoring Performance Standards 1. All wetland types will have at least 45 percent cover at all sample sites at the end of Year 3 (2013), 80 percent cover at the end of Year 5 (2015). 2. All sites will have an observable increase in percent cover, species diversity and plant age/size class throughout the monitoring period. 3. Non-native/weeds vegetation percent cover will not exceed 10 percent of the enhancement site at the end of Year 3 (2013). 4. Scrub-shrub/forested wetland will establish at least 15 percent vegetative cover of woody species at the end of Year 3 (2013) and 30 percent vegetative cover at the end of Year 5 (2015). 5. Plant survival is required to be 75 percent at Year 5 (2015) of the total of installed plant number.

22 3.0 Wetlands Performance Monitoring 4 Years of Monitoring Completed Year 5 (2015) is Final Year to Achieve USACE Permit Compliance USACE Performance Criteria Year 1 (2011) Year 2 (2012) Year 3 (2013) Year 4 (2014) Percent vegetative cover 86% 60% (PEM) 68% 80% Non-native Species 10% 5% 3.5% <5% Woody species percent cover 7% 5.5% 13% 30% Woody Species Density/Survival (0.33 plants/ square foot) >100% (0.49 plants/square foot)

23 3.0 Wetlands Performance Monitoring PP1_E: May, 2010

24 3.0 Wetlands Performance Monitoring PP1_E: August 10, 2010

25 3.0 Wetlands Performance Monitoring PP1_E: August 27, 2010

26 3.0 Wetlands Performance Monitoring PP1_E: May, 2011

27 3.0 Wetlands Performance Monitoring PP1_E: August, 2011

28 3.0 Wetlands Performance Monitoring PP1_B: May, 2010

29 3.0 Wetlands Performance Monitoring PP1_B: May, 2011

30 3.0 Wetlands Performance Monitoring PP1_B: August, 2011

31 3.0 Wetlands Performance Monitoring PP1_B: August, 2011

32 3.0 Wetlands Performance Monitoring PPBP_1720S: April, 2010

33 3.0 Wetlands Performance Monitoring PPBP_1720S: August, 2011

34 3.0 Wetlands Performance Monitoring PPBP_1720S: August, 2012

35 3.0 Wetlands Performance Monitoring PPBP_1720S: August, 2012

36 4.0 Summary & Conclusions Worth the Effort Public has been overwhelming satisfied with the project. Instant aesthetic appeal of the wetland areas played a big part in this. High recreational/transportation usage by public, year round. High usage by wildlife (including waterfowl), without degradation during establishment. Successful agency collaboration (USACE, ITD, Idaho Department of Lands, EPA).

37 4.0 Summary & Conclusions Good Year 4 Wetland Monitoring Results Wetland sod established well adjacent to Sand Creek and in emergent wetland areas. Sod species composition has changed based on which species were most responsive to existing hydrology at the site. Species competition at a specific hydrologic regime or elevation resulted in migration of species composition at a given elevation over 4 years. Sod excluded invasive species well in PEM area: invasive species occupied less than 10 percent of cover for Y3 and Y4. Overall very little invasive vegetative cover has been identified in areas that had sod application. PSS areas slow establishment of shrub material due to drought conditions.

38 THIS IS THE END J. Morrison Presentation given by CH2M HILL, Inc