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TIAA Woodlands Tech Campus (Not Constructed) Fall 2011 Wetland Mitigation Monitoring Report WETLAND MITIGATION PLAN FALL 2011 PERFORMANCE MONITORING REPORT TIAA WOODLANDS TECHNOLOGY CAMPUS ARMY CORPS OF ENGINEERS PERMITS NO. 2004 -00868 and NWS- 2008 - 608 -NO BOTHELL, WASHINGTON Prepared Fora TIAA - CREF /CB Richard Ellis 1909214 1h Street SE, Suite 101 Bothell, WA 98021 Prepared By: TALASAEA CONSULTANTS, INC. 15020 Bear Creek RD NE Woodinville, Washington 98077 425 - 861 -7550 13 February 2012 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report TABLE OF CONTENTS Page A. PROJECT OVERVIEW 1 B. MONITORING REQUIREMENTS 2 C. SUMMARY DATA 6 D. MAPS. 9 Figure 1: Vicinity Map Figure 2: Site Overview Plan Figure 3: Photo point, Vegetation Transect, and Groundwater Monitoring Well Locations Figure 4: Fall 2011 Performance Monitoring Photo - points 1 and 2 Figure 5: Fall 2011 Performance Monitoring Photo - points 3 and 4 Figure 6: Fall 2011 Performance Monitoring Photo - points 5 and 6 Figure 7: Fall 2011 Performance Monitoring Photo - points 7 and 8 E. CONCLUSIONS .......................................................................................... ............................. LIST OF TABLES Table 1: Baseline Assessment Vegetation Transect Data in Wetland Areas (9- 11 -08) 3 Table 2: Baseline Assessment Vegetation Transect Data in Buffer Areas (9 -11 -08 & 1 -6 -09) 4 Table 5: Fall Monitoring Vegetation Transect Data in Wetland Areas (10- 26 -11) 4 Table 6: Fall Monitoring Vegetation Transect Data in Buffer Areas (10- 26 -11) 5 Table 7: Catalog of Native Woody Plant Species (10- 26 -11) 8 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page i TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report A. PROJECT OVERVIEW CORPS PERMITS: NO. 2004 -00868 and NWS- 2008 - 608 -NO Permittee: TIAA - CREF /CB Richard Ellis 1909214 1h Street SE, Suite 101 Bothell, WA 98021 Mr. Stephen Penn, Managing Director Consultant: Talasaea Consultants, Incorporated 15020 Bear Creek Road NE Woodinville, Washington Ann Olsen, Project Manager Field Survey: Conducted on October 26` 2011 by Martha Moritz Project Summary The purpose of the approved plan was to mitigate for wetland and buffer impacts resulting from the development of three multi -story office buildings, a multi -level parking facility, ground -level parking areas, internal roadways and sidewalks, utilities, and stormwater management facilities. The primary goal of the mitigation project was to replace the functions and values lost through wetland impacts including: • Filling 17,491 square feet (sf) of wetlands regulated by the City of Bothell (City), • Filling an additional 4,283 sf of wetlands regulated by Army Corps of Engineers (Corps), • Paper filling 44,299 sf of City regulated wetland. The secondary goal of the mitigation project was to mitigate for development within the outer 100 feet of the 200 -foot shoreline zone for North Creek. To accomplish all of these goals, the following mitigation was completed: • Creating and enhancing 161,456 sf of wetland, • Preserving 131,376 sf of wetland area, • Restoring 800 linear feet (If) or 73,087 sf of the 100 -foot buffer of North Creek, • Stabilizing 500 If of left bank of North Creek, and • Enhancing and preserving 266,471 sf of the wetland buffer. Site Location The site is located in the Canyon Park Business Park in Bothell, Washington (Figure 1). The site is located between the Bothell Everett Highway (SR -527) and 20` Ave SE. The entrance to the site is on 20` Avenue SE, as shown on Figure 1. The mitigation areas encompass approximately 10 -acres of the 28 -acre site and are distinguishable by the different hatch patterns depicted on Figure 2. Driving directions are located on Figure 1. Project Timeframe Construction of the mitigation areas was completed in spring of 2008 and the stabilization of the left bank and restoration of the North Creek buffer area was completed in winter 2008. Monitoring is required by the City and the Corps for five years (2013). The baseline assessment was conducted on September 11, 2008 for all mitigation areas completed spring 2008 and on January 16, 2009 for the North Creek buffer. This fall (2011) concluded Year 3 of the monitoring period. Only annual monitoring events are required for Years 3 -5 of the monitoring period. Biannual maintenance reviews will continue for the duration of the five year period. 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 1 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report Performance Standards The mitigation areas are healthy and functioning as designed. The mitigation areas are currently meeting all of the required performance standards as established by the agencies (see Section B). Maintenance Assessment and Recommendations During the site evaluations conducted on May 3 rd (a maintenance only review) and October 26` 2011, several maintenance items were observed. The following maintenance items were completed in 2011. • Invasive weeds including: Himalayan blackberry (Rubus armeniacus), Scot's broom (Cytisus scoparius), field bindweed (Convolvulus arvensis), birdsfoot trefoil (Lotus corniculatus), bittersweet nightshade (Solanum dulcamara), reed canarygrass (Phalaris arundinacea), and tansy ragwort (Senecio jacobaea) were removed, including the root systems, and disposed of off -site at an appropriate dump location. • Patches of reed canarygrass larger than 3x3 feet were sprayed with glyphosate, which is an herbicide approved for aquatic areas. • Mulch rings were hand - weeded to remove herbaceous material and mulch was reapplied where needed. • The remaining irrigation system was checked for damage and activated by June 15, 2011. The irrigation system was deactivated and winterized by October 15, 2011. The majority of the irrigation system was removed from the site. Irrigation remains in the North Creek Buffer areas installed winter 2008. • Garbage and debris were removed from the site as observed and disposed of off -site at an appropriate dump location. It is expected that regular maintenance will be required to ensure plant survival, satisfy the requirements for success and subsequent release of the performance bond. B. MITIGATION REQUIREMENTS The mitigation areas are being measured for success according to the requirements outlined in the approved Critical Areas report and Mitigation Plan dated 30 March 2005 and the addendum dated 7 January 2005. The following performance standards were established by the City and the Corps. Performance Standard A- In the created wetlands, grading 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 shall 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 at least 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 and grading enhanced existing wetlands and buffers, there will be at least 17 habitat features per acre (1 piece 12,500 so including down woody material (logs, rootwads, etc.) and snags. There will also be a bird nest box installed on each snag. In the planting enhanced wetlands and buffers, there will be at least 3 bat roosting boxes per acre installed on existing large trees. Where feasible, large woody debris (down logs, stumps) will be placed along the outer edges of the enhanced wetlands and buffers at a frequency of one piece per 2,500 sf. Performance Standard D- Herbaceous coverage of vegetation in wetland 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- 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 2 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report 5, excluding those areas of the site that may have sparse herbaceous vegetation due to dense shade from woody species. Performance Standard E- 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 loosestrife, hedge bindweed, Japanese knotweed, English ivy, Canada thistle, and creeping nightshade. Performance Standard F- Following construction, nine (9) shallow groundwater monitoring wells shall be installed in the created and grading enhanced wetlands as well as in preserved Wetland D to ensure maintenance /presence of wetland hydrology. The shallow groundwater monitoring wells must demonstrate, under normal climatic conditions, wetland hydrology for at least 10 percent of the growing season (approximately 24 consecutive days). This performance standard will be satisfied if the wetland areas are flooded, ponded, or saturated to the surface for 24 consecutive days. Saturation to the surface will be defined in non -sandy soils as water present to within 12 inches of the ground surface; or in sandy soils as water present to within 6 inches of the ground surface. Vegetation Sampling Data Ten vegetation sampling transect (VST) locations were established during the baseline assessment within the mitigation areas (Figure 3) and measured 50 to100 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 ten 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. Percent survival was determined by recording the species and quantity of all shrubs and trees. Native, desirable species colonizing the sampling area will be included in the percent survival total. Transect 1, 3 and 6 are located in or adjacent to wetlands and will be measured for herbaceous and woody cover. Transects 2, 4, 5, 7, 8, 9 and 10 are located in buffers and will only be evaluated for woody cover. The established vegetation sampling locations will continue to be monitored and compared to the baseline during each performance monitoring event to aid in determining the success of plant establishment. The following tables show the percent cover and survival of plants at each sampling location during the baseline assessment and the 2011 fall monitoring event. Table 1: Baseline Assessment Vegetation Transect Data for Wetland Areas (9- 11 -08) Transect # & Percent Woody Percent Herbaceous Percent Percent Invasive Cover Length Cover* Cover* Survival VST -1 50' 0 100 100 0 VST -3 70' 7 15 100 0 VST -6 80' 2.5 65 100 0 Average 3.2% 60% 100% 0 Required ** 10% Year 1 30% Year 1 100% Year 1 <20% Years 1 -5 30% Year 3 50% Year 2 85% Years 3 -5 50% Year 5 85% Years 3 -5 *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as established by the City of Bothell and Army Corps of Engineers 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 3 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report Table 2: Baseline Assessment Vegetation Transect Data for Buffer Areas (9 -11 -08 & 1 -6 -09) Transect # & Len th Percent Woody Cover* Percent Survival Percent Invasive Cover VST -2 100' 16 100 0 VST -4 50' 8.4 100 0 VST -5 75' 15 100 0 VST -7 75' 12.1 100 0 VST -8 50' 9.2 100 2 VST -9 50' 5.4 100 0 VST -10 50' 4.4 100 1 0 Average 10.0% 100% 0% Required ** 10% Year 1 100% Year 1 <20% Years 1 -5 30% Year 3 85% Years 3 -5 50% Year 5 *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as established by the City of Bothell and Army Corps of Engineers. Table 3: Fall 2011 Vegetation Transect Data for Wetland Areas 10 -26 -11 Transect # & Percent Woody Percent Herbaceous Percent Percent Invasive Cover Length Cover* Cover* Survival VST -1 50' 22.0 90.0 100.0 10.0 VST -3 70' 53.9 100.0 93.0 0.0 VST -6 80' 60.0 85.0 150.0 15.0 Average 45.3% 91.7% 114.3% 8.3% Required ** 10% Year 1 30% Year 1 100% Year 1 <20% Years 1 -5 30% Year 3 50% Year 2 85% Years 3 -5 50% Year 5 85% Years 3 -5 *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as established by the City of Bothell and Army Corps of Engineers. Table 4: Fall 2011 Vegetation Transect Data for Buffer Areas 10 -26 -11 Transect # & Percent Woody Percent Herbaceous Percent Percent Invasive Cover Length Cover* Cover* Survival VST -2 100' 44.7 85.0 92.3 10.0 VST -4 50' 36.0 100.0 110.0 0.0 VST -5 75' 84.3 80.0 89.8 20.0 VST -7 75' 45.3 90.0 104.6 10.0 VST -8 50' 25.4 0.0 111.8 0.0 VST -9 50' 16.0 90.0 161.0 10.0 VST -10 50' 16.4 1 70.0 1 84.6 1 10.0 Avera a 1 38.3% 73.5% 107.7% 8.6% Required ** 10% Year N/A 100% Year <20% 30% Year 3 85% Years 3 -5 50% Year *Includes desirable species only, invasive plants as defined by the WA State Noxious Weed List are not included. * *Success criteria as established by the City of Bothell and Army Corps of Engineers . Hydrology Monitoring Hydrology monitoring is required by the agencies to ensure that the created and enhanced wetland areas on the site maintain the necessary hydrology post- construction. As outlined in Performance Standard F, "Following construction, nine (9) shallow groundwater monitoring wells shall be installed in the created and grading enhanced wetlands as well as in preserved Wetland D to ensure maintenance /presence of wetland hydrology. The shallow groundwater monitoring wells must demonstrate, under normal climatic conditions, wetland hydrology for at least 10 percent of the growing season (approximately 24 consecutive days) ". In order to satisfy this requirement, Talasaea installed ten groundwater monitoring wells in February 2009 at the 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 4 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report site to measure the hydrology in the wetlands (Figure 3). These wells are scheduled to be monitored twice weekly for hydrology until three out of five years have been met during normal years of rainfall. This spring 2011 concluded Year 3 of the hydrology monitoring. Hydrology monitoring occurred on site beginning 8 March and ending 15 April 2011. Methodology Precipitation during the early 2011 growing season (February through April) was analyzed to determine if "normal" precipitation patterns were evident during the well monitoring period. We used the general methodology outlined by Sprecher and Warne (2000) for NRCS, 30 -day Rolling Total, and Combined Methodology determinations. Determinations of normal patterns of precipitation during a well monitoring period is important to show the presence or absence of wetland hydrology as defined by the Army Corps of Engineers Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual. Western Mountains, Valleys, and Coast Region (April 2008). Wetland hydrology under the Interim manual is defined as inundation or saturation to within 12 inches of the soil surface for 14 consecutive days during the growing season. However, the originally approved monitoring plan requires 24 consecutive days of inundation or saturation within 12 inches of the soil surface. Monthly total precipitation during the monitoring period is compared to values contained on a WETS table (for a local weather monitoring station) to determine whether the month's precipitation is normal, wetter than normal, or drier than normal (NRCS methodology). For the purposes of determining more accurate representation of local weather patterns, a custom WETS table was generated using over 20- years of daily precipitation data from a weather station maintained by Everett Community College. This analysis is also performed using a 30 -day rolling total for precipitation instead of a monthly total for each day of well monitoring. The results of these two analyses are compared and combined to determine if precipitation patterns during the well monitoring period conformed to the range of normal values. C. SUMMARY DATA On October 26` 2011, Talasaea Consultants conducted the fall performance monitoring event for the mitigation areas. The following is a summary of our findings. Wildlife Bird species observed during this and previous site visits included: varied thrush, great blue heron, numerous pairs of mallards, golden- crowned kinglets, belted king fisher, Bewick's wren, red wing blackbirds, black- capped chickadees, song sparrows, Oregon juncos, Canada geese, red - tailed hawk, a pair of nesting eagles, violet green swallows, barn swallows, and killdeer. The resident bald eagle was observed in the cottonwoods trees located in the existing forested Wetland D. The site is well used by amphibians and aquatic macro inve rte brates as evidenced by the Pacific tree frogs and dragonflies observed on site. At the time of the site visit, Sockeye salmon were seen spawning in North Creek. Both Coho and Sockeye have been identified in this stretch of the creek during past site visits. A large number of down logs, stumps and boulders are present in the mitigation areas. There are well over the required amount specified in Performance Standard C. Bat and bird nesting boxes are also present on site and were inspected for damage during the fall monitoring event. 2011 Hydrology Monitoring Summary We analyzed the general patterns of precipitation for the monitoring period between 8 March and 15 April 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. 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 5 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report Based on this analysis of precipitation patterns for the early growing season of 2011, the groundwater levels measured on the TIAA site can be considered valid for determining wetland hydrology. Nine of the ten wells consistently recorded groundwater levels above 12 inches for a minimum of 24 consecutive days during the early part of the growing. Several of these wetland areas were saturated to the surface or surface ponding was observed. The monitoring results from these nine wells satisfy the requirements as stated in Performance Standard F. As noted in the 2009 and 2010 reports, Well #9, which is located in Wetland C (Figure 3) did not exhibited adequate hydrology for the 2009 -2010 growing seasons as required by the performance standard. The groundwater levels within the well during 2011 were measured between 3 -12 inches below the surface of the soil for approximately 60% of the monitoring period. This is a great improvement from the previous years when the well was either dry or measured between 16.25 -17.25 inches below the surface for a majority of the monitoring period. We believe that groundwater interflow is returning to this wetland after being affected by several factors both before, during, and after construction as discussed in last year's report. Over the next two years we will continue to monitor the hydrology in Wetland C and provide a summary in the annual report. Even though the wetland only met the performance standard for 60% of the 2011 season, the wetland is completely dominated by several facultative (FAC & FACW) species that are thriving. The 2011 hydrology monitoring completes the requirements for all of the remaining wetland areas as required per Performance Standard F. No hydrology monitoring will be conducted for these areas during the 2012 growing season. Water Quality and Site Stability Water quality in the wetland areas appeared good. No oil sheen, surface films, foul odor or signs of turbidity were noted during the monitoring events. North Creek flows along the southwestern boundary of the TIAA Campus in a southeasterly direction for approximately 1,240 linear feet (If) before exiting the site under a bridge at 220th Street SE. The bank stabilization that was completed in October 2008 along North Creek has prevented further erosion from occurring on the left bank. Willow spp. and red -osier dogwood have grown on the floodplain creating a dense band of riparian vegetation along the creek. No signs of erosion were observed along the banks of North Creek within the TIAA property. The wetland and buffer areas on the site are well vegetated and stable and no signs of erosion or rilling were observed. Photo - points A series of photographs representing panoramic views of the mitigation areas were taken at eight 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 3. Vegetation Summary Overall, the site is healthy and thriving. A number of native species are volunteering in the wetland and buffer areas, increasing the species diversity and habitat complexity through the site. These species include: thimbleberry, salmonberry, Scouler's willow, big -leaf maple, red alder and black cottonwood. Willows species are well established along the shorelines of the wetland ponds and in and around the various wetlands through the site. The established willows provide protection and nesting areas for the number of dabbling duck species regularly observed on site. Numerous species of obligate wetland grasses, sedges and rushes are establishing in the enhanced and created wetland areas of the site. Dense hedges of red -osier dogwood and native rose spp. are establishing in several areas of the site. The different species of conifers are well established, producing cones and showing visible signs of growth from year to year. Native, deciduous trees are growing tall, creating a varied strata within the 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 6 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report developing forest canopy. The larger wetland complexes and those adjacent to existing wetland areas have grown the most robust. Some of the smaller, isolated wetlands have not established as quickly, but are still meeting all of the required performance standards. By the end of the 2011 growing season, the percent woody cover for the three transects (Transect 1, 3 & 6) in the wetland areas averaged 45.3 %. This exceeds the required 30.0% woody cover for the end of Year 3 of the monitoring period. In the buffer areas, the percent woody cover for the seven transects (Transect 2, 4, 5, 7 -10) averaged 38.3 %. The average percent woody cover measured during the fall monitoring event also exceeds the required 30% cover by the end of Year 3. This satisfies the requirement for Performance Standard A. The average percent of herbaceous cover within the wetland areas measured 90.0 %, which exceeds the required 85.0% cover for Years 3 -5 of the monitoring period. This satisfies the requirement for Performance Standard C. Herbaceous cover is rapidly establishing through the buffer areas and was visually estimated to be an average of 73.5% through the site. Desirable native herbaceous plants, including wild ginger, fringe cup, cleavers, Pacific bleeding heart, and bracken fern were observed establishing in the buffer areas. There is no performance standard for herbaceous cover in the buffer areas, but we are including this data to demonstrate the overall health of the mitigation site. Percent survival for the transects located in the buffer areas is exceeding the required 85% due to successful recruitment and colonization of native woody species. The average percent survival for the transects located in the buffer area was 107.7% by the time of the fall monitoring event. This exceeds the requirements defined in Performance Standard B. There are several transects that reflect a percent survival that is over 100.0% due to natural plant recruitment that is occurring on site. A decrease in percent woody cover was recorded in VST -9 and VST -10, from the 2010 monitoring report. However, these transects do show an increase in percent survival due to natural recruitment occurring within the transect locations. Although native woody vegetation is present in these areas, the woody cover is not well established along the transect line. As the new plants become more established, an increase in woody cover is expected. In the stream, wetland and buffer areas, 33 species of desirable native plant species were recorded during the monitoring event. This exceeds the species diversity requirement outlined in Performance Standard A (at least 15 species). The following table is a summary of the native tree and shrub species found within the TIAA Woodlands Technology Campus mitigation area. 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 7 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report Table 5: Catalog of Native Woody Plant Species 26 October 2011 Scientific name Common name Acercircinatum Vine maple Acermacro h llum Big-leaf maple Alnus rubra Red alder Amelanchier alnifolia Serviceberry Betula papyrifera Paper birch Corpus nuttallii Pacific dogwood Corpus sericea Red -osier dogwood Cor lus cornuta Beaked hazelnut Crataegus dou lasii Black hawthorn Gaultheria shallon Salal Holodiscus discolor Oceans pra Lonicera involcurata Black twinber Mahonia a uifolium Tall Oregon grape Malus fusca Western crabapple Oemleria cerasiformis Indian plum Physocarpus capitatus Pacific ninebark Picea sitchensis Sitka spruce Po ulus balsamifera var. trichocar a Black cottonwood Pseudotsu a menziesii Douglas fir Rhamnus purshiana Cascara Ribes sap uinuem Red-flowering currant Rosa nutkana Nootka rose Rosa p1socarpa Clustered rose Rubus s ectabilis Salmonberr Rubus parviflorus Thimbleber Salix lasiandra Pacific willow Salix scouleriana Scouler's willow Sambucus racemosa Red elderberry Spirea douglasii Douglas spirea S m horicar os abus Common snowber Tsu a hetero h lla Western hemlock Thu a plicata Western red cedar Viburnum edule High-bush cranber There are a number of invasive species that are being routinely removed as part of a long -term management plan for the site. The management of invasive weeds will be an ongoing process since there will be a continual supply of seed from the adjacent wetland system. The weedy species found on site include: Himalayan blackberry, field bindweed, birdsfoot trefoil, bittersweet nightshade, reed canarygrass, tansy ragwort, and Scot's broom. There continues to be an overall reduction of reed canarygrass on site. It is still present in many areas. A very small amount of Scot's broom, reed canarygrass and Himalayan blackberry has been observed scattered through the remainder of the mitigation areas. The amount of invasive weeds located in the parking lot islands is very small and should be easily eradicated with routine maintenance. Field bindweed was noted in several locations and tansy ragwort was found in one location of the site. No tansy ragwort was found near the pedestrian bridge structure adjacent to 214` ST SE. We will still closely monitor this area for tansy rosettes in the future. Field bindweed has become established in Wetland F and will be closely monitored to prevent further establishment of this weed. The average percent invasive weed cover on site is 8.6% and 8.3% (respectively) for both the wetland and buffer areas. We will continue our management practices to reduce the overall cover of invasive weeds. The site is currently 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 8 TIAA Woodlands Technology Campus Fall 2011 Performance Monitoring Report below the maximum threshold of 20.0% for invasive weeds and is meeting the requirements for Performance Standard E. D. MAPS The following maps are attached to assist the City and the Corps in locating the commercial property, the location of the mitigation areas on the property, and to show the locations of the permanent vegetation transects and photo points. Figure 1: Vicinity Map Figure 2: Site Overview Plan Figure 3: Photo point, Vegetation Transect, and Groundwater Monitoring Well Locations Figure 4: Fall 2011 Performance Monitoring Photo - points 1 and 2 Figure 5: Fall 2011 Performance Monitoring Photo - points 3 and 4 Figure 6: Fall 2011 Performance Monitoring Photo - points 5 and 6 Figure 7: Fall 2011 Performance Monitoring Photo - points 7 and 8 E. CONCLUSIONS The fall performance monitoring event for the wetland mitigation areas and the North Creek buffer areas at the TIAA Woodland Technology Campus was conducted to record the health and growth of the native vegetation, ensure that proper hydrological conditions exist in the wetland areas, and to evaluate wildlife usage of the site. The wetland and buffer mitigation areas are healthy and rapidly exhibiting signs of growth and naturalization. An ecologically diverse collection of woody vegetation was observed throughout the site. Ten transects were monitored on the 10 -acre mitigation site to measure plant growth and health. The site is currently meeting or exceeding all of the required performance standards for minimum number of habitat features, percent woody survival, percent woody and herbaceous cover, percent invasive cover and for species diversity numbers. Adequate hydrology was exhibited in nine of the ten groundwater monitoring wells for three out of five growing seasons. Several of these wetland areas were saturated to the surface or surface ponding was observed. Well #9, located in Wetland C, exhibited wetland hydrology for 60% of the growing season. We will continue to monitor this wetland area for the next two years. Overall, the site looks really great and is functioning as designed. A large number of wildlife species have been observed throughout the site and as construction of the buildings occurs over the next several years we hope the wildlife will continue to utilize the wetlands, buffers and riparian areas of North Creek. We expect as the mitigation areas grow, they will provide increased ecological value to North Creek and its adjacent wetland ecosystems. 13 February 2012 Copyright @ Talasaea Consultants, Inc. 2012 843M Fall 2011 Monitoring Report Page 9