Loading...
HomeMy WebLinkAbout09H- Mitigation Plan Offices: Port Angeles, Washington, Winston and Eugene, Oregon, Rocklin California Main Office: P.O. Box 1239, Winston, OR 97496 ~ Telephone: (360) 460-6451 email: brad@westechcompany.com WESTECH COMPANY Environmental Consulting ~ Site Permitting POND REMOVAL MITIGATION PLAN 1060 WHITNEY ROAD - ASSESSOR’S PARCEL # 996-40-0007 QUILCENE, JEFFERSON COUNTY WASHINGTON April 2022 G. Bradford Shea, Ph.D. Submitted to: JEFFERSON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT 621 Sheridan Street Port Townsend, Washington 98368 Submitted by: WESTECH COMPANY Port Angeles, Washington 98362 WW1687.5-WhitneyRdPondRemMP.TOC/042522/mas i TABLE OF CONTENTS CHAPTER/SECTION PAGE NO. _______________________________________________________________________ 1.0 INTRODUCTION 1 2.0 APPROACH AND METHODS 7 2.1 Approach 7 2.2 Methods 7 3.0 MITIGATION PLAN 8 3.1 Regulatory Requirements 8 3.2 Construction Mitigation 8 3.3 Planting and Monitoring Plan 9 4.0 PLANTING PLAN 11 4.1 Planting Areas 11 4.2 Native Plants and Installation 11 4.3 As-Built Documentation and Monitoring 11 4.4 Performance Standards and Contingency Planning 11 5.0 CONCLUSIONS AND RECOMMENDATIONS 15 5.1 Conclusions 15 5.2 Recommendations 15 6.0 REFERENCES 16 FIGURES Figure 1 Location Map 2 Figure 2 Vicinity Map 3 Figure 3 Project Site Map 4 Figure 4 Project Cross-Section 5 Figure 5 Plan View Pond Removal at 1060 Whitney Road 6 Figure 6 Proposed Plantin Areas 12 TABLES Table 1. Performance Standards for Monitoring Plan 10 Table 2. Native Plants for Planting Areas A and B 13 Table 3. Site Soils 10 APPENDICES Appendix A – Maps & Figures A-1 Appendix B – Site Photographs B-1 Appendix C – Wetland Data Forms C-1 Appendix D – Wetland Rating Forms & Maps D-1 Appendix E – Climate Data E-1 WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 1 1.0 INTRODUCTION This Mitigation Plan is in support of a JARPA Permit Application for removal of a small pond on the property at 1060 Whitney Road (Parcel # 996-40-0007) as requested by several state agencies and Jefferson County. The pond was created by building a berm across a small unnamed stream on the property. At the time it was created, the stream had historically been considered to be a non-fish-bearing stream by the agencies. Washington Department of Fish and Wildlife (WDFW) has recently re-classified the stream as having characteristics of potential fish habitat. In accordance with this determination by the Agency, the property owner, David Whitney, has been requested to obtain permits and carry out excavation of the berm, to restore the stream channel to its natural configuration. Mr. Whitney submitted a JARPA Permit Application to the agencies (WDFW, DNR, DOE and Jefferson County DCD) during October of 2021. Subsequent agency requests included that the owner prepare a Mitigation Plan for restoration of the stream-banks and a 25 foot zone adjacent to the stream. This zone will be replanted with native plants, following the necessary berm removal. This Plan is intended to fulfill those Agency requests (see Figures 1-5). Mr. Whitney also authorized preparation of a SEPA Report to comply with Jefferson County and State regulations. That SEPA Report (Environmental Checklist) has been submitted to the Agencies on April 21, 2022. A Wetland Delineation Report has also been prepared on the small wetland adjacent to the Project Area, which is mainly on the adjacent property owned by the local Home-Owners Association (HOA). Figure 1. Location Map Westech Company 2022 Source: Google Earth 2021 Figure 2. Vicinity Map Westech Company 2022 Source: Google Earth 2021 Figure 3. Project Site Map Westech Company 2022 Source: Google Earth 2021 Figure 4. Project Cross-Section Westech Company 2022 Source: Westech Company 2021 6’ Natural Stream Channel Remove Culverts, Rip-Rap and Soil to Natural Stream Elevation 40’ OHWM Figure 5. Plan View Pond Removal at 1060 Whitney Road (470 42’ 25.47” N.Lat. 1220 47’ 9.04” W.Long) Westech Company 2022 Source: Google Earth 2021 WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 7 2.0 APPROACH AND METHODS 2.1 APPROACH This is a small project which is intended to restore a stream channel to previous conditions. Mitigation Measures have been aimed at restoring the Site to its original condition prior to the owner creating the pond. Those original conditions are an open field, with a stream flowing down the hill south of the driveway. The entire project will be conducted within a small area, roughly 50 x 50 feet. Restoration efforts will be concentrated within that area. South of the Project is the property line to the adjacent HOA property, which is not within the owner’s control. Any other stream restoration efforts will be the responsibility of the HOA or other property owners, where the stream crosses their properties. 2.2 METHODS The Mitigation Plan for the Project was based on the size of the area which will be impacted by excavation adjacent to the pond during removal and field measurements of that area. It is also based on agency requests that mitigation plantings be carried out for a 25 foot area adjacent to the new stream bed. These two criteria are roughly equivalent, since the distances between the outside edges of the berm (west to east) is 45-50 feet, with a 3-5 foot stream channel. This area now occupied by the pond and its berm will constitute the proposed planting areas. Plantings cannot extend beyond the areas defined above, since there is a small non- regulatory wetland to the west and a portion of that wetland to the south of the existing pond berm. These wetlands will be protected by silt fencing as necessary during removal of the pond and re-construction of the stream channel within the present pond and berm. Plants and Planting Areas have been specified to conform with on-site conditions, once the material in the pond berm is removed and graded (and the culverts and pond liner are removed). Chapter 3.0 contains a description of the proposed construction and mitigation process. The details for the Planting Plan are shown in Chapter 4.0 (Planting Plan). WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 8 3.0 MITIGATION PLAN 3.1 REGULATORY REQUIRMENTS The planned Pond Removal Project at 1060 Whitney Road has been requested by Jefferson County, Washington Department of Fish and Wildlife (WDFW), Washington Department of Natural Resources (DNR), and Washington Department of Ecology (DOE). A JARPA Permit has been submitted for the Project to these agencies (Westech 2022a). In addition, a SEPA Extended Checklist has been prepared (Westech 2022b). A Wetland Report is also being prepared on an adjacent wetland, which is very small and mostly lies on the neighboring property owned by the local Home-Owners Association (HOA). This wetland is an unregulated, Category IV Wetland. The unnamed stream on the Property constitutes a Fish and Wildlife Habitat Protection Area (FWHPA) as per a recent WDFW determination. The Site is not in the shoreline zone. It lies roughly 500 feet from the Ordinary High Water Mark (OHWM) of the shoreline, well outside of the 200 foot shoreline zone. The Agencies have specified requirements for a shoreline exemption and a stormwater permit with Jefferson County. 3.2 CONSTRUCTION MITIGATION The Project will include the following features and procedures during construction in order to reduce impacts and create mitigation: 1) Construction will be limited to the dry season, and in a window of time which avoids spawning season for anadromous fish (July 15 – October 30). 2) Water in the stream will be diverted immediately above the driveway to an alternate drainage channel which intersects the stream immediately below the pond. Water will be pumped to this alternate channel in order to achieve dry conditions in the pond during construction. 3) The first step in construction will be removal of the berm adjacent to the culverts and then removal of the two culverts. This will be followed by excavation of materials overlying the rubber pond liner. The pond liner and culverts will be disposed of off-site or recycled as necessary. Earth and rock from the berm will be disposed of at an on-site location, which lies more than 150 feet from the stream and more than 50 feet from nearby drainage channels. WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 9 4) The berm will be sloped to a maximum grade of 3:1 wherever feasible, approximating site conditions before the construction of the berm and pond. Erosion will be controlled by a silt fence on the west and south sides of the construction area, between the construction zone and the small wetlands. 5) The streambed will be allowed to resume its natural channel (roughly flowing down the center of the current pond), following removal of the culverts, berm and pond liner. The streambed will be dug to a depth of 12-18 inches and roughly 2-3 feet in width to conform with the stream channel both above and below the present pond. The streambed will then be allowed to re-configure itself during the fall and winter of 2022 under natural conditions. 6) A Planting Plan has been developed and will be implemented for the areas near the pond removal, which will be impacted by the construction. This will use native plants within about 25 feet on both sides the new stream channel in that area. All plantings will be outside of the adjacent small wetlands, which will be protected from construction by a silt fence to control erosion and prevent siltation of the wetlands. 3.3 PLANTING AND MONITORING PLAN A Planting Plan has been developed for restoring the construction area and enhancing the stream with native vegetation. These plantings will include native grasses, which will be supplemented with low shrubs to help begin re-establishment of a natural buffer zone. This will fit in well with the current adjacent field areas (which has been the site’s condition since the 1800s, according to the owner). The new plantings will need to be monitored for survival as per requirements of Jefferson County. This normally is a documentation of As-Built conditions following planting, followed by five years of annual monitoring reports submitted to Jefferson County. The plants are required to meet Performance Standards (see Table 1) during this period including survival percentage, low percentage of invasive plant species, and control of erosion during the monitoring period. WW1687.5-WhitneyRdPondRemMP.Tab1/042522/mas 10 TABLE 1. PERFORMANCE STANDARDS FOR MONITORING PLAN Standard Indicator # 1 Indicator # 2 Indicator # 3 Indicator Invasive species Remaining and planted native species Signs of erosion Attributes Percent cover Percent cover Any sign of erosions Actions Will not exceed 10 percent • 90 percent cover first year • 85 percent cover in subsequent years Will not be visible in buffer zone. Quantities/Status Less than 5 percent cover of buffer 85 percent cover of buffer No visible erosion in the buffer zone. Time Frame Achieved by first summer following construction project Achieved by first summer following construction project Achieved during construction and maintained thereafter. WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 11 4.0 PLANTING PLAN 4.1 PLANTING AREAS The Site will have two planting areas (Areas A and B) as shown in Figure 6. The areas will be similar in species composition, but the upper area has had species selected for more shade and to blend with the shrubs and trees which occur above (north of) the driveway. 4.2 NATIVE PLANTS AND INSTALLATION Proposed native plant species, numbers and sizes are shown in Table 2 for each of the planting areas. We recommend that the shrubs be clustered, with about 50 percent of each area being planted in native grasses. Shrubs should be placed about 5-6 feet on center and in groups of three or more of the same species. Soils should be evaluated prior to planting and loamy soil imported if necessary. Following planting, a layer of 2-4 inches of mulch should be placed around each plant to help protect against drought and temperature extremes. 4.3 AS-BUILT DOCUMENTATION AND MONITORING Following planting, an As-Built Report should be prepared to document the planting areas. Each year, an annual Monitoring Report should be prepared for the five years required by Jefferson County. The Monitoring Reports should be carried out in the early fall of each year, following the growing season. Reports should be submitted by October 30 each year. Monitoring reports should meet Performance Standards listed below. In the event that Performance Standards are not met, a Contingency Plan should be prepared, and non- surviving plants replaced or substituted as necessary to fulfill Contingency Standards. 4.4 PERFORMANCE STANDARDS AND CONTINGENCY PLANNING Performance standards for plant survival should be 90 percent for the first year and 85 percent for successive years. Invasive plants should be maintained at less than 10 percent at all times (preferably below five percent). Any on-site erosion should be monitored, and contingency measures implemented if erosion is found to be significant or is affecting the adjacent wetland area. Figure 6. Proposed Planting Areas Westech Company 2022 Source: Google Earth 2022 WW1687.5-WhitneyRdPondRemMP.Tab1/050522/mas 13 TABLE 2. NATIVE PLANTS FOR PLANTING AREAS A AND B (Whitney Road Pond Removal) Planting Area Species Scientific Name Number Size A Common snowberry Symphoricarpos albus 8 1 gallon A Tall Oregon grape Mahonia aquifolium 6 1 gallon A Oceanspray Holodiscus discolor 6 1 gallon A Evergreen huckleberry Vaccinium ovatum 6 1 gallon A Salal Gaultheria shallon 8 1 gallon A Sword fern Polistichum munitium 8 1 gallon A Native Grass Mixture Graminae 1 1 pound A Kinnikinnick Arctostaphylos uva-ursi 10 1 gallon B Tall Oregon grape Mahonia aquifolium 6 1 gallon B Evergreen huckleberry Vaccinium ovatum 4 1 gallon B Red flowering currant Ribes sanguineum 6 1 gallon B Common snowberry Symphoricarpos albus 6 1 gallon B Sword fern Polistichum munitium 8 1 gallon B Kinnikinnick Arctostaphylos uva-ursi 20 1 gallon B Native Grass Mixture Graminae 1 1 pound WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 14 4.5 CONTINGENCY PLAN In the event that Performance Standards are not met, a Contingency Plan should be prepared. That Plan should contain measures to restore the buffer and increase planting and improve survival rates. Such a Plan will also include additional erosion control and invasive plant control as necessary. WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 15 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 CONCLUSIONS This Mitigation Plan will effectively restore the pond area following removal. The stream channel and adjoining area will be sculpted to a more natural configuration (less than 3:1 slope). The current berm, culverts and pond liner will be removed. The stream channel will be restored to a configuration similar to the channel above and below the pond. Critical areas (wetlands) adjacent to the pond will be protected using a silt fence. Excess materials will be moved to a site more than 50 feet from stormwater drainages and more than 150 feet from the unnamed stream. Those materials will be spread to match local landscape characteristics. During construction, stream water will be diverted and pumped to an existing drainage which intersects the unnamed stream below the pond. Work will be conducted within dry summer months, outside of fish spawning windows, in accordance with all permits. 5.2 RECOMMENDATIONS Westech Company recommends that the Project, including measures in this Mitigation Report be approved and implemented as specified. Plantings should then be confirmed and monitored in accordance with the Planting Plan and Performance Standards outlined in Chapter 4.0. WW1687.5-WhitneyRdPondRemMP.RPT/042522/mas 16 6.0 REFERENCES Google Earth Pro. 2021-2022. Aerial Photograph images for 1060 Whitney Road. www.googleearth.com. Jefferson County. 2022a. Online Map Database. http://www.co.jefferson.wa.us. Jefferson County, Washington. Jefferson County. 2022b. Jefferson County Critical Areas Code. Title 18.22 JCC. Department of Community Development. Port Townsend, Washington. Westech Company. 2022a. Joint Aquatic Resources Permit Application (JARPA) for 1060 Whitney Road Pond Removal Project, Quilcene, Washington. Westech Company, Port Angeles, Washington. Westech Company 2022b. State Environmental Policy Act (SEPA) Report, Pond Removal Project, 1060 Whitney Road, Quilcene, Washington. Westech Company, Port Angeles, Washington. Westech Company 2022c. Wetland Delineation, Pond Removal Project 1060 Whitney Road, Quilcene, Washington. Westech Company, Port Angeles, Washington.