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NSD Transportation Facility Fall 2011 Wetland Mitigation Monitoring Report WETLAND MITIGATION PLAN FALL 2011 MONITORING REPORT NORTHSHORE SCHOOL DISTRICT TRANSPORTATION CENTER (TIAA PONDS) BOTHELL, WASHINGTON CITY OF BOTHELL PERMIT NO. CAP 2005 -00005 CORPS OF ENGINEERS PERMIT NO. 200500908 DOE ORDER NO. 5214 Prepared Fora Northshore School District 2210523 rd Drive SE Bothell, WA 98021 Prepared By: TALASAEA CONSULTANTS, INC 15020 Bear Creek Road NE. Woodinville, Washington 98077 425 - 861 -7550 6 February 2012 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report TABLE OF CONTENTS Page A. PROJECT OVERVIEW 1 B. REQUIREMENTS. 2 C. SUMMARY DATA 4 D. FIGURES ...................................................................................................... .............................. Figure 1: Vicinity Map & Driving Directions Figure 2: Vegetation Transect and Photo -point Locations Figure 3: Hydrology Monitoring Photo -point Locations Figure 4: Spring and Fall 2011 Performance Monitoring Photo -point 1 Figure 5: Spring and Fall 2011 Performance Monitoring Photo -point 2 Figure 6: Spring and Fall 2011 Performance Monitoring Photo -point 3 Figure 7: Spring and Fall 2011 Performance Monitoring Photo -point 4 Figure 8: Hydrology Monitoring Photo -point 1 Figure 9: Hydrology Monitoring Photo -point 2 Figure 10: Hydrology Monitoring Photo -point 3 Figure 11: Hydrology Monitoring Photo -point 4 Figure 12: Hydrology Monitoring Photo -point 5 E. CONCLUSIONS 7 LIST OF TABLES Table 1: Baseline Assessment Vegetation Transect Data (23 April 2010) ... ............................... 3 Table 2: Spring 2011 Vegetation Transect Data (3 May 2011) .............................................. ..... 3 Table 3: Fall 2011 Vegetation Transect Data (26 October 2011) ................. ............................... 3 Table 4: Catalog of Woody Vegetation at TIAA Ponds (26 October 2011) .... ..............................5 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page i Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report A. PROJECT OVERVIEW CITY OF BOTHELL PERMIT NO. CAP 2005 -00005 CORPS PERMIT NO: 200500908 DOE ORDER NO. 5214 Permittee: Northshore School District 2210523 rd Drive SE Bothell, WA 98021 Ms. Laura Brent Consultant: Talasaea Consultants, Incorporated 15020 Bear Creek Road NE Woodinville, Washington 98077 Ann Olsen, Project Manager (425) 861 -7550 Field Survey: Conducted on 3 May and 26 October 2011 by Martha Moritz Project Summary Originally, the mitigation areas at the Northshore School District Transportation Center, hereinafter referred to as the "TIAA Ponds" were part of a larger permitting effort that has since been separated into three different projects. The TIAA Ponds were constructed separately from the other projects. The TIAA ponds were created as off site mitigation for impacts to wetlands at the Northshore School District Transportation Center. Critical area impacts included: 1) 0.35 acres of Category II Wetland 2) 0.3 acres of Category IV Wetland and 3) 0.1 acres of Category III Wetland. This report provides data for only the constructed mitigation areas that occurred on the TIAA property. Site Location The site is located in Bothell, WA on the east side of Bothell Everett Highway (SR 527), on the corner of 214` Street SE and 20` Avenue SE (Figure 1). The mitigation areas are located next to Pacific Medical Center at Canyon Park. Driving directions are located on Figure 1. Project Timeframe Construction of the mitigation areas began in the summer of 2007 and was completed in the winter of 2010. No problems were encountered during construction. Monitoring is required by the City of Bothell for five years (2014) and the Army Corps of Engineers (Corps) and the Department of Ecology (DOE) for ten years (2019). The fall 2011 monitoring event concludes Year 2 of the monitoring period. Monitoring events are conducted biannually for the first two years of monitoring and maintenance reviews are conducted twice yearly for the entire monitoring period. Performance Standards Future monitoring will be compared to the baseline conditions to evaluate the performance standards of the project (see Section B). Maintenance Recommendations During the biannual maintenance reviews, several maintenance tasks were observed. The following items were completed during the 2011 growing season. • Trash and debris was removed from the site and disposed of off -site at an appropriate dump location. 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 1 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report • Invasive weeds were removed and disposed of off -site in an appropriate dump location. Weed species removed during the maintenance event included, reed canarygrass (Phalaris arundinacea), Himalayan blackberry (Rubus armeniacus), common vetch (Vicia sativa), and Scot's broom (Cytisus scoparius). • The irrigation system was activated by 15 June 2011 and deactivated and winterized by 15 October 2011. B. MITIGATION REQUIREMENTS The mitigation area is being measured for success according to the requirements outlined in the approved Canyon Park Phase VII Critical Areas Mitigation Report dated September 5, 2006. The following performance standards were approved by the Corps, DOE, and City of Bothell. • Performance Standard A : In the created wetlands and the enhanced existing wetlands and buffers, at least 15 species of desirable native plant species will be present in the mitigation areas at the end of Year 5. Woody plant coverage must be at least 10% by Year 1, 30% by Year 3, and 50% by Year 5. Woody coverage may be comprised of both planted and recolonized native species; however, to maintain species diversity, at no time shall a recolonized species (e.g., red alder) comprise more than 35% of the total woody coverage. • Performance Standard B: Percent survival of planted woody species must be 100% at the end of Year 1, and at least 85% for each subsequent year of the monitoring period. • Performance Standard C: In the created wetlands, wetland and buffer enhancement areas, and stormwater ponds, there will be at least 17 habitat features per acre (1/ 2,500 square feet) including down woody material (logs, rootwads, etc.) loafing logs (within ponded areas) and snags. Large woody debris will only be placed where large equipment is able to access the mitigation areas without causing any further environmental damage to the wetlands and buffers. There will also be a bird nest box installed on each snag. • Performance Standard D: Herbaceous coverage of vegetation in mitigation areas shall be at least 30% by the end of Year 1, 50% by the end of Year 2, and 85% by the end of Years 3 and 5, excluding those areas of the site that may have sparse herbaceous vegetation due to dense shade from woody species coverage. • Performance Standard E : Throughout the five -year monitoring period, a combination of native or naturalized woody and herbaceous vegetation that is predominantly FAC or wetter will cover the wetland areas. Wetland areas will also exhibit evidence of saturated soil conditions (i.e., signs of ponding, water marks, water - stained leaves, or redoximorphic features in the soil) and will remain inundated or saturated to the surface for at least 10% (14 consecutive days) of the growing season, defined as April through mid - November. • Performance Standard F : After construction and following every monitoring event for a period of five years, exotic and invasive plant species will be maintained at levels below 20% total cover in the mitigation areas. These species include: Scot's broom, Himalayan and evergreen blackberry, reed canarygrass, purple Ioosestrife, hedge bindweed, Japanese knotweed, English ivy, Canada thistle, and bittersweet nightshade. 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 2 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report Vegetation Sampling Data Three vegetation sampling transects were established during the baseline assessment within the mitigation areas (Figure 2). Transect 1 (T -1) and Transect 2 (T -2) measured 50 -feet in length, and Transect 3 (T -3) measured 100 -feet in length. Percent areal cover of shrubs and trees was evaluated in each transect through the use of line- intercept sampling methodology. Using the line- intercept methodology for the three transects, a tape was extended between two permanent markers. Shrubs and trees intercepted by the tape were identified, and the intercept distance was recorded. Percent cover by species was then calculated by adding the intercept distances and expressed as a total proportion of the tape length. A portion of Transect 2 intercepts the edge of the wetland creation area and emergent vegetation along this transect was measured using a quadrat. Emergent vegetation estimated to cover 26.0% of Transect 2. Percent survival was determined by recording the species and quantity of all shrubs and trees within each of the vegetation sampling locations. The following tables depict the data collected during the baseline assessment and the 2011 monitoring events. Table 1: Baseline Assessment Vegetation Transect Data (23 April 2010) Tran sect # Percent Percent Herbaceous Percent Percent Woody Cover* Cover* Survival Invasive Cover 1 20.0 12.0 100 5.0 2 11.4 10.0 100 0.0 3 35.1 5.0 100 0.0 Average 28.8% 9.0% 100 % 1.7% Required ** 10% Year 1 30% Year 1 100% Year 1 <20% 30% Year 3 50% Year 3 85% Years 2 -5 50% Year 5 85% Year 5 *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as required by all of the agencies. Table 2: S rin g 2011 Ve etation Transect Data 3 Ma y 2011 Tran sect # Percent Percent Herbaceous Percent Percent Woody Cover* Cover* Survival Invasive Cover 1 30.2 75.0 100.0 3.0 2 12.8 85.0 93.8 0.0 3 39.1 80.0 113.9 0.0 Average 27.4% 80.0% 102.6% 1.0% Required ** 10% Year 1 30% Year 1 100% Year 1 <20% 30% Year 3 50% Year 3 85% Years 2 -5 50% Year 5 85% Year 5 *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as required by all of the agencies. Table 3: Fall 2011 Vegetation Transect Data 26 October 2011 Tran sect # Percent Percent Herbaceous Percent Percent Woody Cover* Cover* Survival Invasive Cover 1 39.4 80.0 100.0 10.0 2 28.8 85.0 125.0 0.0 3 42.1 90.0 113.9 0.0 Average 36.8% 85.0% 113.0% 3.3% Required ** 10% Year 1 30% Year 1 100% Year 1 <20% 30% Year 3 50% Year 3 85% Years 2 -5 50% Year 5 85% Year 5 *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as required by all of the agencies. 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 3 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report Hydrology Monitoring Hydrology monitoring is required to ensure that the created and enhanced wetland areas on the site maintain the necessary hydrology post- construction for a period of five years. As outlined in Performance Standard E, "Soils must be inundated and/or saturated to the surface for at least 10% (14 consecutive days) of the growing season defined as April through mid - November. A combination of native or naturalized woody and herbaceous vegetation that is predominantly FA C or wetter needs to cover the wetland areas. Wetland areas should also exhibit evidence of saturated soil conditions (i.e., signs of ponding, watermarks, water - stained leaves, or redoximorphic features in the soil)." A series of four photo points were established in March 2011 to establish baseline hydrological conditions. The hydrology photo -point locations are shown on Figure 3. From 28 March — 14 April 2011, Talasaea conducted weekly site reviews to verify that the wetland mitigation areas had sufficient hydrology for at least 14 consecutive days of the growing season. The photos for each photo -point are provided in Figures 8 -12. At the time of the fall monitoring visit ponding was still present in all of the wetland areas. A number of different species of native, emergent vegetation are present throughout the wetland areas. The species observed on site include: hardstem bulrush, slough sedge, common spikerush, broad - fruited burweed, common rush, cattail, and small- fruited bulrush. We analyzed the general patterns of precipitation for the monitoring period between March 28` and April 14` 2011 using both the NRCS methodology and the combined methodology described by Sprecher and Warne (2000). The WETS table used to compare precipitation patterns against the normal range of precipitation was Everett Jr. College. In general, the precipitation for the monitoring period was determined to be normal for the water year. It appears that the mitigation wetland areas on the site have adequate hydrology during a "normal" water year to sustain the installed vegetation including facultative or wetter species throughout the growing season, thereby satisfying Performance Standard E. C. SUMMARY DATA On 3 May and 26 October 2011, Talasaea Consultants conducted the spring and fall performance monitoring events for the wetland and buffer mitigation areas. The following is a summary of our findings. Wildlife Bird species observed during this and previous site visits include the common mergansers, American wigeons, Northern pintails, canvasbacks, black capped chickadee, red wing blackbird, red - tailed hawk, common crow, killdeer, buffleheads, a bald eagle, seagulls, mallards, Canada geese and goslings. Additional wildlife species included Pacific tree frogs and dragonflies. We expect that once the vegetation becomes more established, a moderate number of additional wildlife species will be attracted to the site. Due to the surrounding retail and commercial complexes, it expected that mainly birds, amphibians, fish, reptiles and small mammals will be attracted to the site. Performance Standard B states: In the created wetlands, wetland and buffer enhancement areas, and stormwater ponds, there will be at least 17 habitat features per acre (1/ 2,500 square feet) including down woody material (logs, rootwads, etc.) loafing logs (within ponded areas) and snags. There will also be a bird nest box installed on each snag. During the monitoring site visits, four snags, tethered logs, rootwads and down logs were observed throughout the mitigation areas. In addition, piles of rocks, loafing logs and solitary boulders were also observed. These habitat features provide nesting, feeding opportunities and cover for various 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 4 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report small mammals and reptiles. Four bird nesting boxes were observed on the snags. This site contains well over the required number of habitat features per acre. Water Quality and Site Stability The water observed within the wetlands appears good; no signs of oil sheen or other surface films, abnormal color or odor, or turbidity were noted. Photo - points A series of photographs representing panoramic views of the mitigation areas were taken at four locations (Figures 4 -7). These photographs document general appearance throughout the site, as well as providing a qualitative representation of the success of the mitigation areas. The locations of these photo - points are shown on Figure 2. Vegetation Summary Overall, the native shrubs and trees are healthy and have established well. The general appearance of the installed vegetation is visibly denser and fuller than the 2010 growing season. The performance standard required for percent woody cover by the end of Year 3 is 30.0 %. By the end of Year 2 (fall 2011) the average percent woody cover was measured to be 38.6 %. This exceeds the required performance standard for percent woody cover for Year 3. Transect 1 ends along the edge of an emergent wetland area. Emergent vegetation has become well established and was visually estimated to now cover approximately 15.0% of the transect area. A portion of Transect 2 begins in a willow grove in the ponded area associated with Wetland B. Emergent vegetation has become well established here as well and was measured to cover approximately 26.0% of the transect. There are several types of emergent wetland species present on site. These species include: hardstem bulrush, slough sedge, common spikerush, broad - fruited burweed, common rush, cattail, and small- fruited bulrush. The entire fringe of the mitigation wetland ponds are well vegetated. Herbaceous cover has established well throughout the site. Desirable herbaceous species were visually estimated to cover an average of 85.0% of the site by the fall monitoring event. This meets the requirement for Performance Standard D. Percent survival for the three vegetation transects produced an average of 113.0 %. There are some areas of the site where natural plant reproduction has already begun to occur. The installation of the warranty replacement plants and an increase in the number of snowberry, twinberry, rose sp. and ninebark has boosted the percent survival to above 100.0% for all three vegetation transects. The one -year replacement plants were installed in the mitigation areas in March 2011. In the wetland and buffer areas, 20 species of desirable native plant species were installed. Twenty five species were verified within the mitigation areas. This includes native woody species that have volunteered at the site that has increased the plant diversity within the site. This meets the required performance standard outlined in Performance Standard A. The following table provides a list of species verified within the TIAA ponds mitigation area. 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 5 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report Table 4: Catalog of woody vegetation at TIAA Ponds (26 October 2011) Common name Scientific name Baldhip rose Rosa gymnocarpa Big-leaf maple Acermacro h llum Black cottonwood Po ulus balsamifera (var. trichocar a) Black twinberry Lonicerainvolucrata Clustered wild rose Rosa p1socarpa Common snowberry S m horicar os albus Douglas fir Pseudotsu a menziesii High-bush cranberry Viburnum edule Kinnikinnick Arctosta h los uva -ursi Nootka rose Rosa nutkana Oregon ash Fraxinus latifolia Pacific ninebark Ph socar us ca itatus Pacific willow Salix lasiandra Paper birch Betula papyrifera Red alder Alnus rubra Red elderberry Sambucus racemosa Red -osier dogwood Corpus sen Salal Gaultheria shallon Salmonberry Rubus s ectabilis Scouler's willow Salix scouleriana Serviceberry Amelanchier alnifolia Tall Oregon grape Mahonia a uifolium Thimbleberry Rubus parviflorus Vine maple Acercircinatum Western red cedar Thu a pllcata A maintenance event was conducted in May 2011 to remove the invasive weeds found on the property. Poison hemlock, reed canarygrass, Himalayan blackberry, common vetch and Scot's broom were removed from throughout the site. These invasive weed species were removed, including root systems. All material was disposed of off -site at an appropriate dump location. The driplines of installed vegetation were carefully hand - weeded where necessary in order to free some of the smaller, native groundcovers and shrubs. The average percent invasive cover measured during the fall monitoring event was 3.3 %. With continuing, regular maintenance of the mitigation site, we expect the weeds to be removed and disposed of off -site. The percent cover of invasive weeds is below the maximum threshold and meets the established requirements outlined in Performance Standard F. 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 6 Northshore School District Transportation Center (TIAA Ponds) Fall 2011 Monitoring Report D. MAPS The following maps are attached to assist the agencies in locating the mitigation property and to show the locations of the permanent vegetation transects and photo points. Figure 1: Vicinity Map & Driving Directions Figure 2: Vegetation Transect and Photo -point Locations Figure 3: Hydrology Monitoring Photo -point Locations Figure 4: Spring and Fall 2011 Performance Monitoring Photo -point 1 Figure 5: Spring and Fall 2011 Performance Monitoring Photo -point 2 Figure 6: Spring and Fall 2011 Performance Monitoring Photo -point 3 Figure 7: Spring and Fall 2011 Performance Monitoring Photo -point 4 Figure 8: Hydrology Monitoring Photo -point 1 Figure 9: Hydrology Monitoring Photo -point 2 Figure 10: Hydrology Monitoring Photo -point 3 Figure 11: Hydrology Monitoring Photo -point 4 Figure 12: Hydrology Monitoring Photo -point 5 E. CONCLUSIONS The spring and fall monitoring events for the mitigation areas at Northshore School District Transportation Center (TIAA Ponds) were conducted to record the health and growth of the vegetation, to ensure that proper hydrological conditions exist in the mitigation areas, and to evaluate wildlife usage of the site. A diverse collection of woody and herbaceous vegetation is present in the mitigation areas. The woody vegetation is healthy and areal coverage is expected to steadily increase over the 10 year monitoring period. The site is meeting or exceeding all of the required performance standards for the end of Year 2 established by the agencies. Emergent vegetation has become densely established along the pond edges and is expected to continue to spread and increase in species diversity. The wetland ponds are full of water a majority of the year and the weir structures are functioning as designed. Hydrology monitoring began in March of 2011 to establish a baseline of hydrological levels. Several obligate, emergent wetland species have been observed along the pond edges. Levels of invasive weeds are below the maximum threshold and are regularly removed during routine maintenance events. We conclude that the mitigation areas at the TIAA Ponds are currently meeting or exceeding the established success criteria. The mitigation areas are performing as designed. The installed plant material is healthy and is expected to continue to flourish in the mitigation areas. Productive colonization by desirable native species has begun to occur and will greatly improve habitat quality and species diversity. A number of wildlife species are regularly observed during monitoring visits. We expect that the mitigation areas will provide increased ecological value to the North Creek watershed. 6 February 2012 Copyright © 2012 Talasaea Consultants, Inc. 864TM Fall 2011 Monitoring Report Page 7