Loading...
HomeMy WebLinkAbout023Donna Frostholm From: Donna Frostholm Sent: Thursday, August 13, 2009 1:30 PM To: David W. Johnson Subject: Brinnon MPR - Wetland Comments and Recommendations David: I have reviewed the Wetland and Wetland Buffer Mitigation Plan, Draft Report prepared by GeoEngineers, Inc (dated August 21, 2008), and on August 11, 2009, 1 conducted a site visit to verify the wetland categories using the 2004 Wetland Rating System. As part of preparing these comments, I also reviewed the Grading and Drainage Technical Engineering Report (prepared by Craig A. Peck & Associates, September 4, 2009 Draft) and the Final Environmental Impact Statement (FEIS) prepared for the proposed Brinnon Master Planned Resort (dated November 27, 2007). Based on my site visit and review of the submitted materials and FEIS, I have the following comments: Wetland Cateaorv. I agree with the wetland ratings for Wetlands B, C, and D. I also agree that Wetlands B and D require a 150 -foot buffer and Wetland C requires an 80 -foot buffer. Miticwtion Plan. The draft mitigation plan addresses compensation for the permanent loss of Wetland B and buffer reductions at Wetlands C and D. I reviewed the draft mitigation plan for compliance with Jefferson County Code (JCC) requirements, as they pertain to wetlands and wetland buffers. Wetland HVdrologu. Currently, the natural processes occurring within the project area provide a sufficient amount of water to the 3 on-site wetlands to support wetland conditions. These wetlands are typically inundated for a portion of the year, with much, if not all, of the surface water gone in the drier times of the year. The draft mitigation plan states that water levels within the wetland mitigation area and the existing wetlands will be manipulated to receive reclaimed water from the golf course. The draft mitigation plan also refers to the amount of water entering the wetlands post -construction as greater than current conditions and refers to it as "enhanced" hydrologic patterns. The Jefferson County Code (JCC) considers alteration of wetland hydrology to be a regulated activity. If wetland hydrology is manipulated post -construction (meaning that wetland hydrology is not present due to natural processes and/or the hydrologic budget is not similar to that under existing conditions), then the alteration is subject to the critical areas requirement in the JCC. It should be noted that the FEIS states Wetlands C and D will not be altered by the proposal. The draft Grading and Drainage Technical Engineering Report indicates that kettles will be used for stormwater control, but does not specify which kettles. Two of the kettles are not wetland and Wetland B is proposed to be filled. However, two kettles in the project area are wetland (Wetlands C and D), and are protected under JCC critical areas requirements. The applicants should clearly indicate which kettles are to be used for stormwater control. As noted above, alterations to Wetlands C and D are to be avoided. Figure 3 of the draft mitigation plan shows construction of an overflow stream between Wetlands C and D. Currently, both Wetlands C and D are kettle wetlands that do not have a surface water connection, and Wetland C is located at the bottom of steep slopes. The draft mitigation plan does not address construction of an overflow stream to these wetlands, although alterations to the existing environment would be substantive. Based on Figure 3, it appears that the intent is to direct excess water from Wetland C east to Wetland D via a proposed overflow stream post -construction. It is important to note that Wetland D extends off-site to the east and that steep slopes are mapped as occurring east of the Wetland D. The applicants cannot "enhance" wetland that is not on their property nor can they create conditions where more water may be directed towards slopes that are not within the project area. The applicants should clarify what is being proposed. Wetlands C and D as well as the mitigation area rely on precipitation, surface water runoff, and subsurface flow to support wetland hydrology and maintain wetland conditions. Given the extent of alterations proposed in the project area (including cut and fill), the applicants need to provide additional information about hydrologic conditions at these 3 wetlands post -construction. This should include, but is not limited to, an assessment as to how the geomorphology and drainage patterns will be altered by development in the drainage are for the wetlands. As noted above, if development activities result in altered hydrologic conditions within the wetlands and wetland buffers, then the proposed activity is subject to regulatory review to JCC requirements for critical areas. Wetland B (Impact Area). The applicants are proposing to use a non -wetland kettle on the property as a mitigation for impacts to Wetland B. Based on my review of the draft mitigation plan, I have the following comments: 1. Grading is addressed on page 11 of the draft mitigation plan and the bottom mitigation kettle elevations are highlighted in yellow (in the text of the report). The raised height of the kettle bottom in the text does not appear to match elevations shown on Figures 8 and 9. Based on information in the draft mitigation plan, the applicants are proposing to place at least 5 feet of clay and silt (or "clay -rich" soil) in the wetland mitigation area with an additional 12 inches of hydric topsoil, which would be placed over the clay and silt layer. The slopes to the mitigation area are steep and the applicants should confirm that the heavy equipment needed to compact the clay and soil layer can access the mitigation area. The percent compaction should be specified in the mitigation plan. In the final mitigation plan to be approved by the County, a detailed grading plan of the mitigation area should be included. 2. The draft mitigation plan states that the top 12 inches of hydric soil at the mitigation site will come from the top 24 inches of soil in Wetland B. Typically, only the upper 6 to 12 inches of the soil profile is topsoil; below that is subsoil, which is less likely to support vegetation. Based on the soil description from the wetland delineation report prepared for this project (and received by Jefferson County on August 4, 2006), it appears that only the upper 6 inches of soil at Wetland B would be considered usable as topsoil at the mitigation site. Since the mitigation area is twice the size of the impact area, the applicant should specify in the mitigation plan where the necessary topsoil will come from for use in the mitigation area. 3. The draft mitigation plan states on page 11 that native species from Wetlands B, C, and D will be used. The JCC considers alteration of wetland vegetation a regulated activity. Use of native plants from Wetland B are appropriate for use in the mitigation area. However, plants from Wetlands C and D and associated buffers cannot be removed for use elsewhere in the project area. The text of the mitigation plan should be revised accordingly. 4. The draft mitigation plan indicates that salvaged plants from the project area will be used to replant the mitigation area. While it is acceptable to use salvaged plants, it should be noted that it is generally stressful for large, well-established vegetation to be transplanted and that there is a greater potential for plant mortality (as compared with installation of young vegetation). Much of the project area consists of large trees with a well- developed understory. Many of the trees on the property are much too large to transplant, and it is unlikely that the most of the shrubs on the site would survive being transplanted. The mitigation plan should address survival of transplanted vegetation, identify those portions of the buffer mitigation area to be planted on a figure, present the on -center spacing within these planting areas, and evaluate whether plants obtained from a nursery will be needed to establish native vegetation in the 150 -foot buffer. 5. The mitigation plan should address who is responsible for removing non-native and/or invasive species from the mitigation area and address disposal of undesirable vegetation. 6. A goal of the mitigation plan is to provide on-site, in-kind compensatory mitigation. Wetland B is well vegetated and has no open water areas during the drier months of the year. The mitigation proposal, however, includes an open water component that is not proposed for planting. The draft mitigation plan needs to be revised to address this discrepancy. 7. The first bulleted performance standard listed on page 18 should be revised to state that no more than 10 percent coverage of exotic and undesirable species shall be present throughout the monitoring period, not just at the end of the monitoring period. 8. A performance standard should be added to address wetland hydrology (that matches the goals of the of the mitigation proposal). 2 9. The mitigation plan needs to be submitted to Jefferson County no later than December 31 of each monitoring year. The draft mitigation plan should be revised to clarify that monitoring plans must be submitted by the end of the calendar year. 10. The mitigation plan should state that the outer edge of the wetland buffers will be staked prior to beginning any ground -disturbing activities. 11. The mitigation plan should state that silt fencing and orange barrier fencing will be installed along the outer edge of the wetland buffers prior to beginning any ground -disturbing activities. 12. The mitigation plan should state that the project biologist will be on-site during plant installation to ensure that healthy plants are being installed as per an approved plan. Wetlands C and D (Buffer Reduction). The applicants are proposing to reduce a portion of the wetland buffers at Wetlands C and D. 1. The text of the mitigation plan states that the buffer reductions would not be greater than 25 percent of the standard buffer widths, yet the figures in the report show buffer reductions well beyond 25 percent. The mitigation plan must be revised to address this discrepancy and bring the proposed buffer reduction into compliance with JCC requirements. 2. Some of the total square footage calculations in the legend of several figures do not match the area calculations shown in the drawing on Figure 10. The figures need to be corrected. 3. There is a net decrease in the Wetland C buffer area (543 square feet), as proposed in the draft mitigation plan. Also, there is a buffer reduction shown on the figures at Wetland C to construct Fairway 1 that has not been accounted for in the draft mitigation plan. The applicants need to state why the fairways cannot be located outside of the wetland buffers and provide more information as to how a net decrease in wetland buffer area could comply with JCC buffer reduction requirements as they pertain to functions and values. 4. A mix of native and non-native species are currently present in the buffers for Wetlands C and D. The draft mitigation plan only shows the locations of paved or gravel roads for re -planting as part of the buffer reduction. The draft mitigation plan should indicate the plant composition of the additional buffer areas. If areas consisting of non-native species are present in the buffer addition areas, then the draft mitigation plan should address these areas. Wetland Functions and Values. Following are my comments pertaining to wetland functions and values. 1. Figure 3 shows wildlife corridors on the golf course. No information is provided in the draft mitigation plan as to what habitat features, if any, will be placed within a wildlife corridor or what constitutes a wildlife corridor. The draft mitigation plan does not identify what type of wildlife would be expected to use the wildlife corridors to move from wetland -to -wetland. 2. Fencing is proposed to prevent the people from entering into the mitigation site, but no mention of fencing is proposed to protect Wetlands C and D and associated buffers. The mitigation plan should also address protection of these wetlands. 3. To fully understand the potential impacts to wetland area, wetland functions and values, and wetland processes, the applicants need to provide information on the extent of cut and fill proposed within the project area. The draft report should be revised to address all potential impacts of the proposed development and re -submitted for County review. The extent of impacts should be based on what was presented in the FEIS. Note that a final mitigation plan will be needed for project permitting that would include, but is not limited to, detailed planting plans and specifications, detailed plans specifying type and location for habitat features noted in the text of the mitigation plan, fencing specifications, revised construction schedule, and updated monitoring schedule. Let me know if you have any questions, IO&rwtal Frojth4o LiMi .Associate Aanner/1WetlandSpeciaCtst Jefferson County Devecopment Review Division 621 Sheridan Street 3 Port Townsend, Washington 98368 Jrosth6m@co jeff"erson.wa.zas 360.379.4466 All e-mail sent to this address will be received by the Jefferson County e-mail system and may be subject to Public Disclosure under Chapter 42.56 RCW.