Loading...
HomeMy WebLinkAboutWetland Mitigation 721162001 I I I I I I I I I I I I I I I I I I I mUMlP - '-lql.t -:f.OtJoCp- 04f?: WETLAND BUFFER ENHANCEMENT PLAN FOR THE NORTH BEACH DRIVE PROPERTY PORT LUDLOW Jefferson County, Washington TPN 721162001 JC Case # MLA06-00496 Prepared For: Robert and Linda Lingenbrink 4590 NW Newberry Hill Road Silverdale, W A 98383 Prepared By: ~L .6, _ .=';; t~(A4 Joanne Bartlett Wiltermood Associates, Inc. 1015 SW Harper Road Port Orchard, W A 98367 (360) 876-2403 March 23, 2007 I I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS PAGE INTRODUCTION 1 WETLAND AND BUFFER CONDITIONS 2 PROJECT DESCRIPTION 3 BUFFER REDUCTION 3 BUFFER ENHANCEMENT PLAN OVERVIEW Goals of the Enhancement Plan Planting Plan and Specifications 4 5 5 PERFORMANCE STANDARDS 6 MONITORING PLAN 7 MAINTENANCE PLAN 8 CONTINGENCY PLAN 9 PERFORMANCE BONDS 9 LIMITATIONS & BIOLOGIST SIGNATURE 10 I I I I I I I I I I I I I I I I I I I INTRODUCTION This wetland buffer enhancement plan has been prepared for the buffer reduction proposed at the property located on North Beach Drive in the Bridgehaven Division 7 development in Port Ludlow, Jefferson County, Washington. The identified and delineated wetland is an estuarine emergent community associated with the Bridgehaven Channel that meets the criteria for a Category II system. The Jefferson County Code Section 18.15 requires 100 foot buffers from the delineated boundary of Category II wetland systems and permits reductions when buffer averaging is not feasible and a buffer enhancement plan is submitted. Compensation in the form of enhancement is required for buffer reductions so that the reduced buffer functions as good as or better than the buffer at the required width. The required 100 foot buffer encompasses the entire upland portion of this parcel, which lies at the south end of Bridgehaven Channel and is one of the few remaining undeveloped lots in this division. of Bridgehaven. It is mostly level and appears to have been formed by historic fill. The west side of the property is steeply sloping up to North Beach Drive and South Point Road. The slope extends northerly from this property and the Bridgehaven Channel lies at the base of the slope. A home is proposed at the south end where the terrain is level and a buffer of 30 feet can be accommodated between the home and estuarine wetland. There are no alternatives to the proposed building area as the remainder of the parcel, which extends northerly along North Beach Drive and South Point Road, is steeply sloping, is also within the 100 foot buffer and the vegetation cover is a well established mixed forest. The selected building and reduced buffer areas are currently cleared and dominated by invasive plant species that extend to the delineated wetland boundary. The etisting buffer vegetation includes mostly invasive grasses, weeds and shrubs with scattered existing conifer trees and small clumps of native shrubs. The enhancement plan proposes to remove the invasive vegetation and replace with the proposed native plantings. The existing native trees and shrubs will be retained. The planting plan proposes to install the selected species within the reduced buffer area so that there is good vegetation cover between the future home and estuarine wetland. Plants to be installed in the enhanced buffer include Nootka rose, ocean spray, Indian plum, serviceberry, snowberry, mock orange, Oregon grape, shore pine, western red cedar and Sitka spruce. The variety of plants is proposed to establish a trend toward a multi layer buffer of shrubs with scattered conifer trees that typically occur at low elevations and along shoreline communities. The plants are proposed from the most salt tolerant to the least salt tolerant with the salt tolerant species, including Nootka rose, Ocean spray, and shore pine closer to the wetland and the other species furthest from the wetland. Lower plants are proposed in a portion to allow a view from the future home down Bridgehaven Channel. Plant installation will take place during the first winter after homesite construction so that they are not impacted by construction activities, although they can go in at anytime if buffer impacts are avoided. I I I I I I I I I I I I I I I I I I I Monitoring will be required for a period of five years to occur in years 1, 2, 3 and 5 following implementation of the enhancement plan to ensure that the plants survive and grow to emulate a multi layer shrub community. Maintenance will be necessary during the five year monitoring period to remove non~natives so that they do not hinder the growth and survival of the installed plants. Watering maybe required each summer of the 5 year monitoring period at least one time per week to ensure survival of the installed plants. Three performance standards will be used to gauge the success of the enhancement plan and they include at least 90 % survival of the installed plants and less than 15 % cover by non-natives/invasives during each year of the five year monitoring period and at least 50 % cover by the native volunteer and installed plants by the end of the five year monitoring period. Yearly percent cover standards are proposed to ensure that there is increasing cover over the 5 year monitoring period. Contingency measures will include installation of plants if the survival rate is below the specified standard during the first two years or installation of additional plants if percent cover standards are not being met. WETLAND AND BUFFER CONDITIONS The parcel for which this delineation was completed is located at the south end of the Bridgehaven channel, which is formed by the now heavily developed sand spit on the east side and the steep slopes down from South Point Road. There is a rapidly eroding channel on the east side of the property around the culvert that conveys water from estuarine wetland to the south (off-site south of North Beach Drive) into Bridgehaven channel. The parcel is generally level at the south end but is steeply sloping along the west edge and to the north. The level area appears to have been created in historic. fill and represents the only buildable area on this property. This area is open grassland and the vegetation is dominated by a mixture of grasses, weeds and invasive shrubs with a few conifer trees on the west and east ends (see attached photos). The steep slopes extend up to North Beach Drive and South Point Road and end at the west edge of Bridgehaven Channel. The sloping portion is dominated by a forested community having a canopy of coniferous and deciduous trees and a thick shrub layer. The Bridgehaven Channel is considered an estuarine community because it is enclosed by a narrow spit and it is generally composed of open water with exposed saltmarsh along the upper edges and mudflat throughout the remainder at low tide. The vegetated saltmarsh community occupies the upper limit of tidal saltwater along the north edge of this property and along the entire west edge of the channel. This community is dominated by saltgrass with lower percentages of Douglas aster, seaside arrowgrass, pickleweed and Lyngby's sedge. The saltmarsh community extends northerly along the west edge of Bridgehaven Channel and the upland forest vegetation overhangs from the upland slope. The channel itself appears to be dredged to maintain water deep enough to facilitate boat travel to docks adjacent to many of the single family homes. 2 I I I I I I I I I I I I I I I I I I I The delineation was conducted around the upper limits of the saltmarsh community beginning at the east property line and extending to the west property to identify the limits of both the estuarine and palustrine wetland communities on this parcel (see Wetland Delineation Report that accompanies this enhancement plan). The estuarine wetland meets the criteria for a Category II system according to the revised Washington State Wetland Rating System (DOE publication #04-06-025) because it is an estuarine system that only meets 1 of the 3 criteria listed in question SC 1.2 of the rating form. The wetland also meets the criteria for a Category II estuarine wetland using the 1993 Washington State Wetlands Rating System (DOE Publication #93-74). The Jefferson County Critical Areas Ordinance (CAO) requires a 100 foot buffer for Category II wetlands to be measured horizontally from the delineated wetland boundary. The palustrine wetland area represents a very small community that extends upslope from the saltmarsh and is not separately categorized because the estuarine wetland buffer extends beyond buffers required for the forested wetland. The buffer and wetland encompass aU of the property so a buffer reduction is necessary to accommodate the proposed single family home, which will be positioned at the south edge of the property as shown on the attached site plan. PROJECT DESCRIPTION A single family home is proposed in the hatched area of the attached site plan but it appears that the home will be located toward the west end where there is more potential buildable upland. A short driveway will come off North Beach Drive in close proximity to the home and it does not appear that the existing driveway will be utilized as it lies within a portion of the reduced buffer. The remainder of the hatched building site area will be used as lawn and landscaping for the homesite. The buffer will be reduced to about 30 feet, which is the widest buffer possible that permits construction of a home and driveway. The 30 foot buffer width will be maintained along the entire shoreline area of this property as shown on the buffer enhancement plan. The northern portions of the site will be left undeveloped. BUFFER REDUCTION The Jefferson County Code 18.15.340 Protection Standards requires 100 foot standard buffers be established from the delineated boundaries of Category II wetland systems. Buffer reductions are permitted when "the project application includes a buffer enhancement plan using native plant species which substantiates that an enhanced buffer will improve the functional attributes of the buffer to provide additional protection for functions and values." This project is requesting a reduction of the buffer from 100 feet to a maximum of 30 feet to accommodate the future single family home. There are no alternatives to reducing the buffer because the entire parcel is either composed of wetland or the standard 100 foot buffer. 3 I I I I I I I I I I I I I I I I I I I The existing buffer is composed largely of invasive shrubs/vines, tall grasses and weeds with scattered groups of native shrubs and scattered native conifer trees so for the most part, it lacks dominant native vegetation and does not currently have high function as a natural buffer community. Wide buffers are typically required because they are thought to provide better protection for wetland systems particularly when they contain high quality native trees and shrubs but when buffers are dominated by low growing plants (non-native grasses or weeds), they do not function properly and do not provide significant protection for wetland functions and values. Enhancement of buffers is thought to improve vegetation conditions and in most cases, it is thought that reduced buffers that are enhanced with native trees and shrubs provide better protection for the resource than the disturbed buffer at its required width. This is substantiated in Condition 1 (8C.2.5.1-attached) of Conditions for Increasing the Width of, or Enhancing, the Buffer in the Department of Ecology's Wetlands in Washington State, Volume 2, Protecting and Managing Wetlands. This condition is titled Condition 1: Buffer is not Vegetated with Plants Appropriate for the region and states: "The recommended widths for buffers are based on the assumption that the buffer is vegetated with a native plant community appropriate for the ecoregion or with one that performs similar functions. If the existing buffer is un-vegetated, sparsely vegetated or vegetated with invasive species that do not perform needed functions, the buffer should either be planted to create the appropriate plant community or the buffer should be widened to ensure that adequate functions are provided. Generally, improving the vegetation will be more effective than widening the buffer. " As mentioned previously, the wetland buffer on this site is composed mostly of weeds and tall grasses with only sparse cover by native trees and shrubs and as'such, does not function as a high quality native buffer. It will be enhanced significantly by installing clumps of native shrubs . that occur in Western Washington lowlands including along shorelines and a few trees so that it will function to provide better protection for the wetland. The buffer in some locations is being planted with lower shrub species so that a view of Bridgehaven Channel can be maintained particularly north of the future home. The buffer enhancement will allow the buffer to function better at its reduced width than it would at its required width. BUFFER ENHANCEMENT PLAN OVERVIEW A single family home is proposed at the south end of this property and cannot be situated outside the required Category II 100 foot wetland buffer so a reduction to 30 feet is proposed. Enhancement will take place within the estuarine wetland buffer, which is composed of invasive shrubs, grasses and weeds with scattered conifer trees and small groups of native shrubs. Blackberries will be removed from the old road that extends north from the future building site across a portion of the Palustrine forested wetland and Sitka spruce and western red cedar trees will be planted. The invasive plants will be removed as part of the overall enhancement in both the Palustrine wetland and estuarine wetland buffer. Once the invasive plants are removed, clumps of shrubs including Nootka 4 I I I I I I I I I I I I I I I I I I I rose, ocean spray, serviceberry, Indian plum, snowberry, Oregon grape and mock orange will be installed throughout. Shore pines will be scattered throughout the shrub clumps and western red cedar and Sitka spruce will be installed along the old road and at the west end of the enhanced buffer area. The existing conifer trees and groups of native shrubs will be retained on the site. Goal of the Enhancement Plan The goal of this enhancement plan is to improve the existing buffer conditions by removing the invasive species and replacing with clumps of native shrubs of varying heights and scattered conifer trees. By replacing the non-native plants from the reduced buffer and installing native trees and shrubs, the buffer vegetation conditions will be improved and there will be an overall increase in buffer function. Seven species of shrub and three species of trees are proposed to create a diverse community of tall and short stature shrubs. To achieve the stated goals, the plan includes a monitoring and maintenance plan that will involve frequent visits to the site to document the condition of the plants and remove invasive plant species. To determine whether the goals of this plan are being met, performance standards have been developed and will be used to monitor the enhanced buffer over a period of 5 years following implementation. The performance standards will include 90% survival rate among the installed plants, at least 50% cover by native vegetation in the enhanced buffer and less than 15 % cover by non-native plants including but not limited to Himalayan blackberry, Scot's broom and English ivy. The survival rate and non-native plant cover standards are expected to be met every year of the S year monitoring period and yearly percent cover increases are proposed to monitor whether the SO% cover standard will be met by the end of the five year monitoring period. Planting Plan and Specifications The plants chosen for this enhancement plan are native and common to Jefferson County. The plants as listed below and shown on the enhancement drawing (attached) shall be obtained from regional native plant nurseries and the shrubs will be planted about 6 feet apart and the trees will be 10 feet apart or scattered as shown on the enhancement drawing. Clumps of native shrubs each containing 12 plants will be planted throughout the enhanced 30 foot buffer. Shore pines are proposed in the shoreline buffer and the cedar and spruce trees are proposed where the old road crosses the Palustrine, Forested portion of the on- site wetland. The planting plan only indicates the location of the plantings but it is diagrammatic and on the ground installation may vary based on actual site conditions. Since the plants will be installed as potted individuals, they can be installed during the summer months although they must be watered on a regular basis. Plant installation is higWy recommended during the winter months (October ISth to March ISth) when the plants are dormant so that they are in the ground at the start of spring growing season. 5 I I I I I I I I I I I I I I I I I I I BUFFER ENHANCEMENT PLANT LIST Symbol Quantity Common Name Botanical Name Size and Spacing A 48 N ootka rose Rosa nutkana 1 gal B 24 Serviceberry Amelanchier alnifoUa 1 gal C 36 Ocean spray Holodiscus discolor 1 gal D 12 Indian plum Oemleria cerasiformis 1 gal E 24 Snowberry Symphoricarpos albus 1 gal F 12 Tall Oregon grape Mahonia aquifolium 1 gal G 24 Mock orange Philadelphus lewisii 1 gal * 13 Western red cedar Thuja pUcata Min. 24" * 8 Shore pine Pinus contorta contorta Min. 24" * 10 Sitka spruce Picea sitchensis Min. 24" Removal of invasives will be conducted by mowing, weed eating and/or hand pulling. Heavy equipment will only be used if it can be staged outside the 30 foot buffer because soil damage may occur. After removal of the invasives, the plants will be laid out by hand at the specified spacing or as shown on the enhancement plan and not measured out by string line. The plants will be installed by digging a one to two foot diameter hole and placing the plug from the pot into the ground once the soil around the plug is loosened. The hole will then be backfilled with the dug out soil and loosely packed down around the plug. Substitutions might be necessary for species or individuals that cannot be found at local nurseries and all plant substitutions shall be approved by the project biologist prior to installation. The project biologist will be on-site prior to installation of the plants to verify that the species, quantity, and sizes of the plants are correct and each plant is healthy and free of disease. The biologist shall also assist the landscapers with placement of plants in the areas specified on the enhancement plan. An as-built design shall be prepared upon completion of the plant installation and submitted to Jefferson County Department of Community Development (DCD) showing the location of the plants and any alterations to the approved enhancement plan. Follow-up monitoring shall commence after submittal/approval of the as-built and will occur once at the end of four of the five growing seasons following plant installation. PERFORMANCE STANDARDS The performance standards have been developed to monitor the success of the installed plants with respect to the survival of individuals and percent cover provided by native plants (installed and naturally occurring) by the end of the five year monitoring period. The following performance standards have been developed for this enhancement plan: 6 I I I I I I I I I I I I I I I I I I I 1. Survival Rate-Every Monitoring Year · 90 % survival of planted species within the enhanced buffer. 2. Percent Cover by Native Plants · Year One-at least 15 % cover by installed native plants · Year Two-at least 25 % cover by installed native plants · Year Three-at least 35 % cover by installed native plants . Year Five-at least 50 % cover by installed native plants. 3. Plant Height-End of the Five Year Monitoring . The conifers shall be at least 7 feet tall, tall shrubs shall be at least 5 feet tall and the lower shrubs should be at least 3.5 feet by the end of the five year monitoring period. 4. Non-Native Invasive Coverage-Every Monitoring Year . Less than 15% cover by non-native exotics, including English ivy, Himalayan blackberry, and Scot's broom MONITORING PLAN Monitoring will occur for a period of five years following installation of the plants to track the success of the project and to ensure that the performance standards and objectives are met. Monitoring will take place at the end of the summers in Years 1, 2, 3 and 5 (August or September, which is considered the end of the growing season) so that the plants have had a chance to grow through the entire growing season. The performance standards will be monitored by dividing the enhancement area into smaller monitoring units to document the cover and survival rate within those units (unit sizes to be determined during plant installation/as built preparation). Survival rate and percent cover of installed plants will be monitored in the respective monitoring units. Performance Standard #1-Survjval Rate-Survival rate will be determined by counting the number of live plants within each monitoring unit and dividing by the number of plants originally installed (per design and as built), which will give a percent survival rate for each unit. Performance Standard #2-Percent Cover-The percent cover standard will be monitored as if looking over each monitoring unit from above and estimating the area covered by the individual species. The percent cover within an area can total greater than 100 % because of the overlap in plant cover provided by the tree, high/low shrub and herbaceous layers. Performance Standard #3-Height of Trees and Shrubs-The height of the plants shall be monitored each year using any type of measuring device but may be most easily monitored by using a wooden carpenter's measure or yardstick to determine the yearly heights of the installed plants. 7 I I I I I I I I I I I I I I I I I I I Performance Standard #4-Cover by Non-Natives-The cover by non-native plants, which on this site will include English ivy, Scot's broom, and blackberry, should be kept below 15 %, which is why regular maintenance is required. The cover by these species will be determined through the same process as determining the cover of installed plants. If the percent cover by non-natives rises above 15 %, more intensive maintenance must be conducted. The monitoring phase of the project will begin upon submittal and acceptance of the as built report, which will show the location of the plants installed using photos and hand drawn maps, upon completion of plant installation. The as built drawing will be used in the five year follow up monitoring to track the changes in vegetative cover and document the survival rate of the plants installed as part of the enhancement plan. Photos will be taken of each monitoring unit to visually document the changes that occur over the five year monitoring period. Photo stations will be established at several points around the enhanced buffer so that the entire area is visually documented over the 5 year monitoring period. Pre and Post planting photos will be included in the as built to show early conditions and these photos will be used during each of the monitoring reports to document the change in buffer conditions from dominated by invasives to dominated by natives. The as built report will be submitted to the regulatory agencies within a month of implementation. Monitoring at the end of the growing season will allow the maximum growth and survival of the individual plants to be documented. Photos will be taken of the enhanced buffer from the points established during completion of the as built so that the same areas are visually documented over the entire five year monitoring period and the changes can be easily compared. The photos and data collected during each monitoring visit will be compiled into a report and submitted to Jefferson County DCD to verify that the enhancement plan is developing as designed and is meeting the performance standards. The report will address whether the mitigation performance standards are being met during each monitoring year and if the final end of monitoring period standards are going to be met. Monitoring results will determine whether or not contingency measures will be needed. MAINTENANCE PLAN The enhanced buffer shall be maintained at least twice during the growing season of each monitoring year to increase the survival of the plants, particularly with respect to providing water during the summer months and clearing of invasive species. Hand clearing should be done around the individual plants because it will reduce the impact to the installed plants. Hand clearing will be necessary at least two times during each growing season to ensure the weeds and grasses do not hinder the growth and development of forested communities in the enhanced buffer. The presence of any other native shrub or tree species (red alder, salmonberry, willows, trailing blackberry, sword fern, etc.) not specifically planted in the 8 I I I I I I I I I I I I I I I I I I I buffer shall be considered part of the planting plan and will not be removed, unless they begin to compete and cause widespread die-off of the installed plants. Removal of invasives may not be necessary after three years if the plants are growing well and there has been no problem with invasive plant species. Watering of the installed plants may be necessary during the drier portions of the year to ensure plant success and can be done by hand or sprinklers. The installed plants may not require regular watering after the third year if they have proven successful in terms of survival and percent cover increases. Fertilization of the installed plants, using a granular fertilizer appropriate for native species, may be necessary to initiate growth and provide nutrients that are not necessary present in the soil. Broadcast fertilizers will not be used because they could impact quality of downstream waters. CONTINGENCY PLAN Although the success of the enhancement plan is not ensured, it is likely to succeed because of the size and scope of the project. If for some reason the survival rate is less than 90% plants that did not survive will be replaced with the same or a similar native species with the approval of the project biologist. Replacement will occur in the dormant season immediately following the g{owing season in which less than 90% survival was recorded. If at any time during the monitoring period, the percent cover standard is not being met, additional plants may be installed to ensure that the ends of S year monitoring period standards are met. If at the end of the fifth monitoring year, the vegetation does not cover at least SO% of the enhanced buffer, additional plants may need to be installed. Maintenance activities will be continued for those replaced plants to ensure their survival. The performance bond will ensure that the project will be carried out to its conclusion if the current owners fail to implement the enhancement plan or monitoring. Monitoring may be extended by another year if the contingency plan is required. PERFORMANCE BONDS Performance bonds are required by the Jefferson County Department of Community Development to ensure fulfillment of the buffer enhancement project, monitoring program and any contingency measures. The bond amounts are determined by estimating the cost of the plants and labor to install them, the cost to complete the as built letter to let the county know that the enhancement plan has been implemented, and the monitoring/maintenance costs. There are two performance bonds. The first covers implementation of the enhancement plan and will be released following submittal and acceptance of the as built by the county. The second covers maintenance and monitoring and will be released upon acceptance of the final monitoring report by the county. The amount by which the estimated costs must be multiplied will be determined by Jefferson County. 9 I I I I I I I I I I I I I I I I I I I Implementation of Enhancement plan 211-gallon bareroot and/or containerized plants, labor & tax included (Based on native plant nursery price list as per planting specs) Removal of invasives-mowing, hand pulling, and/or weed eating Cost for supervision by project biologist (estimated: 3 hours @$90/hr) Supervision of plant installation As-Built design and letter $1,688.00 1,000.00 270.00 720.00 $3,678.00 TOTAL FOR INSTALLATION PHASE Monitoring (After Plant Installation) Year One Monitoring Year Two Monitoring Year Three Monitoring Year Five Monitoring Monitoring Total Maintenance (Twice Yearly Weed Removal and weekly watering) Year One Maintenance Year Two Maintenance Year Three Maintenance Year Five Maintenance Maintenance Total $720.00 720.00 720.00 720.00 $2,880.00 $500.00 500.00 SOO.OO SOO.OO $2,000.00 $4,880.00 TOTAL FOR MONITORING/MAINTENANCE PHASE LIMITATIONS This report has been prepared for Robert and Linda Lingenbrink. Given the constraints of schedules and scope of work, Wiltermood Associates, Inc. warrants that the work performed is in accordance with the technical guidelines and criteria in effect at the time this report was prepared. The enhancement plan and report were prepared by the signer. The results and recommendations of this report represent professional opinion based upon the information provided by the client, the client's consultants, and that gathered through the preparation of this buffer enhancement plan. It is important to note that the Jefferson County Department of Community Development will have the final determination of whether the enhancement plan meets the intent of the Jefferson County Code. No other warranty, expressed or implied, is made. Signed ~CUL1'LL ---:;?,~ Joanne Bartlett, Professional Wetland Scientist 10 I I I I I I I I I I I I I I I I I I I 8C.2.S Conditions for Increasing the Width of, or Enhancing, the Buffer Condition 1: Buffer is Not Vegetated with Plants Appropriate for the Region The recommended widths for buffers are based on the assumption that the buffer is vegetated with a native plant community appropriate for the ecoregion or with one that performs similar functions. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer should either be planted to create the appropriate plant community or the buffer should be widened to ensure that adequate functions of the buffer are provided. Generally, improving the vegetation will be more effective than widening the buffer. 8C.2.S.1 8C.2.S.2 Condition 2: Buffer Has a Steep Slope The review of the literature (Volume 1) indicates that the effectiveness of buffers at removing pollutants before they enter a wetland decreases as the slope increases. If a buffer is to be based on the score for its ability to improve water quality (see Tables 8C-4 through 8C- 7) rather than habitat or other criteria, then the buffer should be increased by 50% if the slope is greater than 30% (a 3-foot rise for every 10 feet of horizontal distance ). 8C.2.S.3 Condition 3: Buffer Is Used by Species Sensitive to Disturbance If the wetland provides habitat for a species that is particularly sensitive to disturbance (such as a threatened or endangered species), the width ofthe buffer should be increased to provide adequate protection for the species based on its particular, life-history needs. Some buffer requirements for priority species are available on the Washington State Department ofFish and Wildlife web page (http://wdfw.wa.govlhab/phsrecs.htm). The list of priority species for vertebrates is at http://wdt\v.wa.llov/hab/phsveli.htm; for invertebrates it is at http://wdfw.wa.llov/hab/phsinvrt.htm. Information on the buffer widths needed by some threatened, endangered, and sensitive species of wildlife is provided in Appendix 8-H. 8C.2.6 Buffer A veraging The widths of buffers may be averaged if this will improve the protection of wetland functions, or if it is the only way to allow for reasonable use of a parcel. There is no scientific information available to determine if averaging the widths of buffers actually protects functions of wetlands. The authors have concluded that averaging could be allowed in the following situations: Averaging may not be used in conjunction with any of the other provisions for reductions in buffers (listed above). Wetlands in Washington State Volume 2 - Protecting and Managing Wetlands 12 Appendix 8-C Guidance on Buffers and Ratios - Western Washington April 2005 I I I I I I I I I I I I I I I I I I I REFERENCES Guard, B. Jennifer. Wetland Plants of Oregon and Washington. Lone Pine Publishing. 1995. 239 pp. Hitchcock, Leo C. and Cronquist, Arthur. Flora of the Pacific Northwest. University of Washington Press. 1973. 730 pp. Granger, T., T. Hruby, A. McMillan, D.Peters, J Rubey, D. Sheldon, S. Stanley, E. Stockdale. Apri12005. Wetlands in Washington State-Volume 2: Guidance for .Protecting and Manageing wetlands. Washington State Department of Ecology. Publication # 05-06-008. Olympia, W A. Jefferson County Unified Development Code, Title 18, Land Use Districts, Chapter 18.15, Article VI-I. Wetlands. Lyons, C.P and Merilees, Bill. Trees, Shrubs, and Flowers To Know in Washington and British Columbia. Lone Pine Publishing. 1995. 375 pp. Pojar, Jim and MacKinnon, Andy. Plants of the Pacific Northwest Coast; Washington, Oregon. British Columbia. & Alaska. Lone Pine Publishing. 1994. 527 pp. Speare-Cooke, Sarah. A Field Guide to the Common Wetland Plants of Western Washington and Northwestern Oregon. Seattle Audubon Society. 1997. 417 pp. US Army Corps of Engineers. Wetland Plants of the Pacific Northwest. September, 1984. 85 pp.