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HomeMy WebLinkAboutSEPA Comment Response MatrixUpper Hoh River Road Bank Stabilization Project - SEPA Reponses to Comments No. 1 2 3 4 5 6 7 8 9 10 11 Commentor Rick Mraz Rick Mraz Rick Mraz Donna Frostholm Donna Frostholm Donna Frostholm Donna Frostholm Donna Frostholm Donna Frostholm Donna Frostholm Donna Frostholm Agency Ecology Ecology Ecology Jefferson County staff biologist Jefferson County staff biologist Jefferson County staff biologist Jefferson County staff biologist Jefferson County staff biologist Jefferson County staff biologist Jefferson County staff biologist Jefferson County staff biologist Comment On the wetland conceptual mitigation plan: • On p. 8 (Monitoring and Maintenance) would you mind adding Ecology to the list of those receiving the monitoring reports? On the wetland conceptual mitigation plan: Would you please describe the existing conditions of the area proposed for wetland creation and the work that would be done to construct the bench (e.g. number and size of trees removed, other vegetation removed)? On the wetland conceptual mitigation plan: • Given its proximity to the OHWM of the Hoh River, can you provide information/discussion on the expected longevity of the wetland mitigation at this site? need to see the Biological Survey and Biological Assessment 1. The Final Environmental Assessment states that a new road will be constructed just west of the C-3 Tower Bridge replacement, and that the road will be replanted once the engineered log jams are constructed. The applicant needs to identify the impacts of constructing the temporary road and include a restoration plan that shows no net loss of shoreline functions. 2. The Memorandum - Conceptual Wetland Mitigation Plan does not provide information about the proposed mitigation site M1. Based on Figure 1 of that memo (aerial photograph), it appears that the area within the proposed mitigation area is very similar to that outside of the mitigation area. The applicant needs to provide more information about the M1 site and address why this area is appropriate for mitigation. If the M1 site consist of large trees with native understory, it should not be used as mitigation. 3. The mitigation area should be designed to be a self-supporting system over time. The Memorandum - Conceptual Wetland Mitigation Plan indicates that a flow spreader will be installed. The applicant needs to provide a mitigation proposal for creating wetland hydrology that does not depend on an engineered system. 4. The Memorandum - Conceptual Wetland Mitigation Plan provides performance standards for monitoring years 1, 3, and 5. Given that it generally takes about two to three years for the roots of installed plants to become established in mitigation areas, the applicant should add monitoring in year 2 and should provide performance standards. 5. The Memorandum - Conceptual Wetland Mitigation Plan states that the existing upland buffer will remain intact so no vegetation performance standards were proposed. Based on the aerial photograph (Figure 1) in the memo, it appears that some upland vegetation would need to be removed for heavy equipment to access the mitigation area and create the bench wetland. 6. The wetland addendum states that there is a potential that a second mitigation site may be needed. If there is a potential that mitigation site M2 will be needed as part of the current application, the applicants must address that mitigation area as well. 7. Mitigation plans should clearly indicate which portions of the proposed development would be mitigated at site M1 and which project components would be mitigated at M2. Response Ecology has been added to the list of those who will receive the monitoring reports. See Chapter 8.0 Monitoring and Maintenance of the Wetland and Stream Mitigation Report. A description of existing conditions in the mitigation area is provided in Section 6.2 Site Selection of the Wetland and Stream Mitigation Report. Section 6.3 Site Design describes the construction technique. Up to one acre of clearing will be required for the temporary 20-foot-wide access road, located approximately 200 feet from the active river channel edge. Vegetation clearing for the newly extended access road will be limited to young alders and willows averaging less than 10 inches diameter of breast height (dbh). An estimated 20 trees will be removed for construction of the stream mitigation area. Future conditions at the mitigation site are discussed in Chapter 7.0 Mitigation Performance Standards in the Wetland and Stream Mitigation Report. Adaptive management techniques will allow the mitigation site to continue functioning for several years. The mitigation project is expected to be in place for many years beyond the 5 years of monitoring. The Biological Survey and Biological Assessment were provided to Jefferson County (Emma Bolin, County Planner) via email on October 11, 2017. A temporary access road will be constructed to install the ELJs for project mitigation near MP 7.3. As discussed in Section 6.3 of the Wetland and Stream Mitigation Report, installation of the ELJs will require limited clearing and temporary improvements to an existing un-graded side road off the UHRR. This unimproved road, which is currently used for drift boat access to the river, will be improved and temporarily extended beyond its existing terminus for construction access. Up to one acre of clearing will be required for the temporary 20-foot-wide access road, located approximately 200 feet from the active river channel edge. The extended portion will be decompacted and replanted with dense native shrubs and trees when ELJ installation is complete. The road will be restored as discussed in the Wetland and Stream Mitigation Report. See the complete Wetland and Stream Mitigation Report. See Sections 6.2 Site Selection and 6.3 Site Design for a description of the mitigation area and of the construction of the mitigation project. The site provides an opportunity to expand the extent and permanency of high-value side channel aquatic habitat in the Upper Hoh River basin. Mitigation will improve the side channel aquatic habitat survivability by reducing the channel migration and avulsion risk and encouraging the development of natural floodplain roughness. The site became side-channel habitat roughly 15 years ago, and this project will encourage the side-channel to continue developing, instead of converting back into the main channel with high winter flows. See the Wetland and Stream Mitigation Report. A flow spreader will not be used as part of mitigation. See the Wetland and Stream Mitigation Report. Visual inspection of ELJs and of the side channel plugs will be conducted each monitoring year, Years 1 through 5, to monitor for movement. Other performance measuring will occur during years 1, 3, and 5, as discussed in detail in Section 7.1 and Table 9 of the Wetland and Stream Mitigation Report. See the Wetland and Stream Mitigation Report. As shown in Figure 2 of the Wetland and Stream Mitigation Report, the upland portion of the mitigation area already has existing road access. Therefore, existing upland vegetation around the proposed mitigation area will be left intact with existing vegetation. No buffer vegetation performance criteria are proposed. See the Wetland and Stream Mitigation Report. A second mitigation project for wetland impacts is not proposed. There is a second site for aquatic mitigation. See the Wetland and Stream Mitigation Report, which discusses the one mitigation site for wetlands near Site C1, and the one mitigation site for streams west of Site C3. All river and stream impacts would be mitigated at the Linder Creek Side Channel Complex mitigation site west of Site C3, between MP 6.7 and MP 7.3.