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2019 WETLAND MONITORING REPORT
SR 539 Ten Mile Road to SR 546 (Wiser Lake) Compensatory Mitigation Site
USACE NWS-2007-470-SOD
Northwest Region
Wetlands Program Issued March 2020
Prepared By: Amanda Mintz
Editor:
Kristen Andrews
Other Contributors: Tatiana Dreisbach
For additional information about this report or the WSDOT Wetlands Program, please contact:
Kristen Andrews, Wetlands Program WSDOT, Environmental Services Office
P. O. Box 47332, Olympia, WA 98504 E-mail: [email protected]
Phone: 360-570-2588
Monitoring reports are published on the web at: http://www.wsdot.wa.gov/environment/technical/disciplines/wetlands/monitoring-reports
Title VI Notice to Public It is the Washington State Department of Transportation’s (WSDOT) policy to assure that no person shall, on the grounds of race, color, national origin or sex, as provided by Title VI of the Civil Rights Act of 1964, be excluded from participation in, be denied the benefits of, or be otherwise discriminated against under any of its federally funded programs and activities. Any person who believes his/her Title VI protection has been violated, may file a complaint with WSDOT’s Office of Equal Opportunity (OEO). For additional information regarding Title VI complaint procedures and/or information regarding our non-discrimination obligations, please contact OEO’s Title VI Coordinator at (360) 705-7090. Americans with Disabilities Act (ADA) Information This material can be made available in an alternate format by emailing the Office of Equal Opportunity at [email protected] or by calling toll free, 855-362-4ADA(4232). Persons who are deaf or hard of hearing may make a request by calling the Washington State Relay at 711.
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Site Summary SR 539 Ten Mile Road (Wiser Lake) Compensatory Mitigation Site USACE NWS-2007-470-SOD
General Site Information USACE IP Number NWS-2007-470-SOD
Ecology WQC 5155
Mitigation Location Three miles south of the City of Lynden on the west side of SR 539 in Whatcom Co.
LLID Number 1224861489020
Construction Date 2008-2009
Monitoring Period 2010-2019
Year of Monitoring 10 of 10
Type of Impact Wetland Open Water Buffer
Area of Project Impact1 1.57 acres 0.98 acre 3.30 acre
Type of Mitigation Wetland Enhancement Buffer Enhancement
Planned Area of Mitigation2 2.53 acres 2.09 acres
1 Impact numbers sourced from WSDOT 2007, page 14, Tables 4 and 7. 2 Additional mitigation for this project is provided at the Potter Road Mitigation Site. Mitigation numbers sourced from WSDOT 2007, page 38.
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Table of Contents Site Summary........................................................................ i
1. Introduction ................................................................ 1
1.1. Summary ........................................................... 1
1.2. Monitoring Results and Management Activities .. 1
2. Site Description ......................................................... 2
2.1. Location ............................................................. 2
2.2. Purpose and Description ................................... 2
2.3. Study Area ......................................................... 3
3. Performance Standards and Methods ....................... 4
3.1. Performance Standards ..................................... 4
3.2. Methods............................................................. 5
4. Discussion ................................................................. 6
4.1. Site Development .............................................. 6
4.2. Results .............................................................. 7
4.3. Adaptive Management ....................................... 9
5. References .............................................................. 10
Figures Figure 1. Site Sketch ........................................................... 3
Figure 2. Sample Design ..................................................... 5
Appendices Appendix A. Planting Plan ............................................ 11
Appendix B. Photo Point Locations ............................... 12
Appendix C. Photo Points ............................................. 13
Appendix D. Data Tables .............................................. 15
539 Wiser Lake 2019 Monitoring Report 1
1. Introduction 1.1. Summary This report summarizes final-year (Year-10) monitoring activities at the 539 Wiser Lake Mitigation Site. Included are a site description, the performance standards, an explanation of monitoring methods, and an evaluation of site success. Monitoring activities included vegetation surveys and photo-documentation on August 14, 2019.
1.2. Monitoring Results and Management Activities
Performance Standards 2019 Results Management Activities
60% cover native facultative or wetter woody species in the forested and scrub-shrub wetland communities
95% cover (qualitative)
90% cover emergent species 70% cover (qualitative)
50% cover native facultative or wetter woody species in the buffer communities
95% (qualitative)
No more than 20% cover non-native invasive species across the site
5% cover (qualitative) Weed control occurred in March, April, June, August, and October of 2019.
No Japanese knotweed (Reynoutria japonica) or purple loosestrife (Lythrum salicaria) across the site
None observed
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2. Site Description 2.1. Location The Wiser Lake mitigation site is located three miles south of the city of Lynden on the west side of State Route (SR) 539 (Guide Meridian) in Whatcom County.
Driving Directions: Head north on Interstate 5 towards Bellingham. Take Exit 256A for SR 539/Meridian Street. Turn right (North) onto SR 539 North/Meridian Street. Follow SR 539 north for approximately eight miles. The site is located on the west side of SR 539 just after crossing East Bartlett Road. It is on the southwest shore of Wiser lake. Park in front of the stormwater pond.
2.2. Purpose and Description This 4.62-acre mitigation site (Figure 1) is a wetland enhancement area west of SR 539 adjacent to the south shoreline of Wiser Lake. This site was created to partially compensate for permanent impacts to 1.57 acres of wetlands and 0.98 acre of open water impacts due to improvements along SR 539. The aquatic bed, emergent, and scrub-shrub wetland and buffer areas are designed to provide mitigation for lost wetland functions including wildlife habitat, toxicant/nutrient removal, export of organic matter, and flood flow alteration.
539 Wiser Lake 2019 Monitoring Report 3
2.3. Study Area The SR 539 Wiser Lake Mitigation Site (Figure 1) includes narrow strips of aquatic bed and emergent wetlands along the shoreline of the lake. The surrounding enhanced wetland and upland buffer provide flood flow alteration, sediment removal, nutrient and toxicant removal, erosion control and stabilization, production and export of organic matter, and wildlife habitat functions for the lake.
Figure 1. Site Sketch
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3. Performance Standards and Methods 3.1. Performance Standards
Year 10 Performance Standard 1 Native facultative or wetter woody species will achieve a minimum of 60 percent coverage in the forested and scrub-shrub wetland communities. Native colonizing vegetation will be included in these coverage calculations.
Performance Standard 2 Emergent species on the Wiser Lake Mitigation Site will achieve a minimum of 90 percent cover including naturally recruited native species.
Performance Standard 3 Native facultative or wetter woody species will achieve a minimum of 50 percent coverage in the buffer. Native colonizing vegetation will be included in these coverage calculations.
Performance Standard 4 No more than 20 percent cover by non-native invasive species as listed in [Appendix D, Table 1] across the entire mitigation sites.
Performance Standard 5 Japanese knotweed and purple loosestrife shall not be tolerated on the mitigation site. The presence of Japanese knotweed, English ivy, purple loosestrife, and Eurasian water milfoil will initiate the invasive species contingency measures.
Appendix A shows the planting plan (Grant 2007).
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3.2. Methods The tables below document sample methods used for all of the performance standards (PS) required by the mitigation plan or permits. Additional details on our methods are located here: WSDOT Wetland Mitigation Site Monitoring Methods Paper (WSDOT 2008). All performance standards were qualitatively evaluated; therefore, no sample design was needed (Figure 2).
Figure 2. Sample Design
PS 1 PS 2 PS 3 PS 4 PS 5
Attribute Cover Cover Cover Cover Presence/Absence
Target population
Native Woody Herbs Native
Woody Invasive species
Noxious Weeds
Zone PSS/PFO Emergent Buffer Entire site Entire site
Sample method Qualitative Qualitative Qualitative Qualitative Qualitative
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4. Discussion 4.1. Site Development This site has developed rapidly and is doing well. The final-year performance standard for native woody cover in the forested/scrub-shrub wetland areas and upland buffer were met early (see Appendix 3, Table 3 for the past two years of monitoring results). Vegetation in this zone is very dense and near 100 percent cover apart from the access trails cut by the restoration crew.
Despite replanting efforts, cover in the emergent area remains lower than intended. This zone is narrow (~1-3m wide) with a steep drop into the lake. The lake may be too deep here to support much of a deep emergent plant community. The willows (Salix species) along the bank are doing well at stabilizing the bank that was previously experiencing erosion. However, they are hanging over the herbaceous plants and possibly shading them out.
Cover of invasive species across the site is low. Most of the invasive species are located in open areas: the emergent zone, the maintenance pathways cut out of the dense wetland and buffer vegetation, and along the outer edges of the buffer. Efforts to control hairy willowherb (Epilobium hirsutum) appear to have been successful; none were detected onsite in 2019. However, there was one small patch of common reed (Phragmites australis) remaining in the emergent zone.
The site is functioning as intended. Rapid vegetative growth provides organic matter export and supports nutrient and toxicant removal, while the dense stem and root systems provide flood flow attenuation, sediment removal, and erosion control. The site is functioning as wildlife habitat; garter snakes, rabbits, and beaver chewed logs were observed at the time of monitoring.
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4.2. ResultsPerformance Standard 1 (60% cover native facultative or wetter woody species in the forested and scrub-shrub wetland communities)
The site has developed more rapidly than anticipated and has been meeting the final year standard for wetland woody cover for eight years. On April 25, 2014 a request to discontinue quantitative sampling for the forested and scrub-shrub communities was sent to USACE and the Department of Ecology; this request was accepted on April 30, 2014. The final year standards are still currently being met.
Cover is qualitatively estimated at 95% (Photo 1) and is primarily composed of roses (Rosa spp.), twinberry honeysuckle (Lonicera involucrata), red osier dogwood (Cornus alba), Pacific ninebark (Physocarpus capitatus), and hardhack (Spirea douglasii).
Performance Standard 2 (90% cover emergent species) Cover of native herbaceous species is qualitatively estimated at 70% in the emergent zone (Photo 2). Dominant species include slough sedge (Carex obnupta), hardstem and softstem bulrush (Schoenoplectus acutus, S. tabernaemontani), broadleaf cattail (Typha latifolia), and swamp smartweed (Persicaria hydropiperoides). Significant cover in this zone is provided by woody species such as willows (Salix spp.) and hardhack (Spirea douglasii). If woody species are included in the result, the cover estimate would increase to 80 percent.
Photo 1. Woody cover in the wetland (August 2019)
Photo 2. Emergent cover on the lacustrine fringe (August 2019)
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Performance Standard 3 (50% cover native facultative or wetter woody species in the buffer communities)
Cover in the buffer communities was qualitatively evaluated due to heavy cover preventing a full quantitative analysis. Cover in this zone has been meeting the final year performance standard for the last six years and is difficult to distinguish from the scrub-shrub wetland zone.
Cover is estimated at 95 percent (Photo 3) and is primarily composed of roses (Rosa spp.), twinberry honeysuckle (Lonicera involucrata), Pacific ninebark (Physocarpus capitatus), and Saskatoon serviceberry (Amalanchier alnifolia).
Performance Standard 4 (No more than 20% cover non-native invasive species across the site)
Invasive cover is qualitatively estimated at five percent across the site. The east end of the emergent area contains a substantial amount of climbing nightshade (Solanum dulcamara).
Performance Standard 5 (No Japanese knotweed or purple loosestrife across the site)
None observed at the time of monitoring.
Photo 3. Woody cover in the buffer (August 2019)
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4.3. Adaptive Management From 2010 through 2019, the emergent species at the lake shore achieved 70% coverage. To meet the performance standard, coverage should be 90%. The WSDOT plant establishment crew replanted this site in 2011, 2013, 2015 and 2016. Despite this ongoing effort, the emergent planting coverage remains below 90%, due to a steep shoreline and willows shading out the emergent plants. This site has run out of funding for the crew to continue replanting. Considering that the site more than meets the other performance standards for coverage, that it nearly meets the emergent coverage standard, and that no funding remains, no further replanting is scheduled for this site in 2020.
Multiple weed control visits are scheduled for 2020.
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5. References 1. [Ecology] Washington State Department of Ecology. 2007. Water Quality Certification Order Number 5155 for Corps
Public Notice Number 200700470 for the SR 539 Tenmile to Badger Transportaion Project in Whatcom County, Washington.
2. Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Vicksburg (MS): US Army Engineer Waterways Experiment Station. Technical Report Y-87-1. Available at: http://www.swl.usace.army.mil/Portals/50/docs/regulatory/wlman87.pdf
3. Grant, L. 2007. Final Wetland Mitigation Report SR 539: Tenmile Road to Badger Road (SR 546 Widening (MP 5.90 to MP 12.62) Planting Plan. Seattle (WA) WSDOT. Northwest Region.
4. [USACE] US Army Corps of Engineers. 2007. Department of the Army Individual Permit Number NWS-2007-470.
5. [USACE] US Army Corps of Engineers. 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0), Wakeley JS, Lichvar RW, Noble CV, editors. Vicksburg (MS): US Army Engineer Research and Development Center. ERDC/EL TR-10-3. Available at:https://www.usace.army.mil/Missions/Civil-Works/Regulatory-Program-and-Permits/reg_supp/
6. [WSDOT] Washington State Department of Transportation. 2007. Final Wetland Mitigation Report SR 539: Tenmile Road to Badger Road (SR 546 Widening (MP 5.90 to MP 12.62). Seattle (WA) Northwest Region Environmental Services.
7. [WSDOT] Washington State Department of Transportation. 2008. WSDOT Wetland Mitigation Site Monitoring Methods. https://www.wsdot.wa.gov/sites/default/files/2018/02/22/Env-Wet-MonitoringMethods.pdf
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Appendix A. Planting Plan (from Grant 2007)
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Appendix B. Photo Point Locations
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Appendix C. Photo Points The photographs below were taken from permanent photo-points on August 14, 2019 and document current site development.
Photo Point 1
Photo Point 2
Photo Point 3
Photo Point 4
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Photo Point 5 Due to site conditions, we were unable to access locations for photo points 6, 7, 8, and 9.
539 Wiser Lake 2019 Monitoring Report 15
Appendix D. Data Tables Table 1. Non-native invasive species (WSDOT 2007) Scientific Name Common Name
Buddleia alternifolia fountain butterfly bush Cirsium arvense Canada thistle Cirsium vulgare Bull thistle Cytisus scoparius Scot's broom Geranium robertianum herb Robert Hedera helix English ivy Ilex aquifolium English holly Iris pseudoacorus yellow flag iris Lythrum salicaria purple loosestrife Phalaris arundinacea reed canarygrass Polygonum cuspidatum (and related species and hybrids) Japanese knotweed Prunus laurocerasus English laurel Rubus laciniatus evergreen blackberry Rubus armeniacus (discolor) Himalaya or Armenian blackberry
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Table 2. Year 10 performance standards met in Years 9 and 10 at Wiser Lake
Performance Standards (Year-10) Year 9 (2018) Qualitative Results Year 10 (2019) Results
Native facultative or wetter woody species will achieve a minimum of 60 percent coverage in the forested and scrub-shrub wetland communities. Native colonizing vegetation will be included in these coverage calculations.
95% cover 95% cover
Native facultative or wetter woody species will achieve a minimum of 50 percent coverage in the buffer. Native colonizing vegetation will be included in these coverage calculations.
90-95% cover 95% cover
