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HomeMy WebLinkAbout2025 03 04 Dosewallips River Collaborative DRAFT Meeting Summary 1 Dosewallips River Collaborative DRAFT Meeting Summary Saturday, March 4, 2025 9:00 AM – 10:38 AM Brinnon Community Center Main Room and Zoom Hybrid Meeting Welcome and Introductions Attending: Heather Dudley-Nollette (District 1 Jefferson County Commissioner), Brian Hemmingway (Dosewallips River landowner), Tressa Linquist (Jefferson County Public Health), Mike Matthews (Dosewallips River landowner), Susan Neil (Dosewallips River landowner), Tami Pokorny (Natural Resources Program Coordinator, Jefferson County Public Health), Morgan Shear (Camp Robbinswold Manager), John Soden (Natural Systems Design [NSD]), George Terry (Department of Community Development), additional Dosewallips community landowners and members of the public Tami Pokorny welcomed the meeting attendees and gave an overview of the Dosewallips River Collaborative, an informal and inclusive discussion group focused on resiliency projects that Jefferson County Public Health is putting forward to benefit salmon species and the community. More information on the Dosewallips River Project can be found at: https://www.co.jefferson.wa.us/1435/Dosewallips- River-Project. Public Comments A resident who has lived on the Dosewallips River for over 30 years shared photos of past flooding events and discussed the County’s response of building dikes and the installation of engineered log jams. He said there was approximately 7,000 feet of dike that needed to be replaced. John Soden noted that the effectiveness of the dikes was one of the topics in the presentation that was going to be made during the meeting. Tami Pokorny welcomed people to stay after the meeting to view and discuss the photos. A member of the public announced that the South County Task Force had been organized to work with the County to mitigate flooding on the lower river. They meet on the first Friday of each month; meetings are open to the public. Additions to the Agenda A request was made to add a discussion on the grant process, which was added under New Business. Approval of the Draft June Meeting Summary There were no objections to an informal approval of the Draft June Dosewallips River Collaborative meeting summary. Tami Pokorny invited people to make corrections or additions to the summary. An archive of past meeting summaries can be found on the Dosewallips River Project page. Announcements There were no additional announcements. Old Business There was no old business. New Business Grant Update 2 Tami Pokorny explained that there was a grant the County had applied for that was related to the flood and erosion risk and salmon habitat restoration work that would be discussed at this meeting. Separately, the County has applied for a grant from the Flood Control Assistance Account Program, which would allow funding for a process for the Brinnon and Lazy C communities to gather information around options to address flood and erosion risk. The funding would help facilitate research and conceptual designs for projects that the community could select and would allow the County to do integrated floodplain management. The request was made for the maximum amount available, which was supported by the Board of County Commissioners. Tami will be sharing more about the grant at Friday’s South County Task Force meeting. John Soden added that the different grants come from different buckets, allocated for fish or for flood and erosion risk, but that one type can often be used to leverage funding for another, and can benefit both humans and wildlife. Tami explained that the type of project selected for integrated floodplain management would be chosen by the community. Presentation: Lower Dosewallips River Assessment: Brinnon Flood and Channel Migration Risk: Dosewallips River, River Miles 0-1.2 John Soden invited input from the group during his presentation. The Lower Dosewallips River Assessment reported on multiple topics throughout the lower river, including fish, habitat, flooding, and erosion risk. This meeting would focus on the flood and erosion risk, while a later meeting would address the fish and habitat sections. In response to a question about salmon habitat, John explained that most of the productive salmon habitat was upstream, but that did not mean that there were no salmon redds in the lower river. More importantly, juvenile salmon use rearing habitat in the lower river during migration. John showed a map of the topography of the lower river that was developed with new LiDAR imagery and showed the various channels of the river along with community landmarks. Channel migration was evaluated using aerial photos from 1938 through 2023. They found that the channel was generally stable upstream of river mile 0.9, but upstream of the US-101 Bridge the sub-reach was quite dynamic. There is a history of channel avulsion and migration downstream of the US-101 Bridge. John went over the history of channel migration in the lower river and areas that are at high risk for future erosion, which would affect not only landowners but also the approach of the US-101 Bridge. The Washington Department of Natural Resources mapped deep-seated landslides around river mile 0.8 to 1, where the risk of future slope failure increased with channel migration and hillslope toe erosion. A landslide would likely cause immediate change to channel alignment and would increase flood and erosion risk towards Brinnon. Landowners discussed historic landslides and flood events. John focused on four areas of heightened flood risk at 1: the overflow channel north of the fire station, 2: the low area near the Community Center, 3: the berm area from river mile 0.4 to 0.7, and 4: the low area between the Dosewallips State Park Campground and US-101. The two primary flows used for the discussion were a 2-year flood flow (5,293 cubic feet per second) with a mean higher high water tide, where most of the water stays in the side channels but there is no real flood damage, and a 100-year flood flow (16,337 cubic feet per second) with a mean higher high water tide, which could see water flowing through the Dosewallips State Park Campground and causing major flood damage. Hydrologic modeling showed the flood risk for the two events at the four locations: 1: At the overflow channel north of the fire station, it showed minor inundation from high tide during the 2-year flood, and impoundment of water near Schoolhouse Road and at US-101 during the 100-year flood. John noted that no flooding has been documented at Schoolhouse Road, and that it would 3 probably take a large debris jam coinciding with the 100-year flood event and high tides; however, it was not a zero risk. 2: At the low area near the Community Center, the model showed minor inundation influenced by sea level and high tide during the 2-year flood, and impoundment of water along US-101 from a combination of flows from the west and tidal inundation during the 100-year flood. Concerns were expressed by the group regarding determinations being made about flood zones that then become regulatory for landowners. Tami Pokorny asked people to send her their questions and ideas about planning and projects so that she can incorporate those priorities into her grant requests. 3: At the berm area from river mile 0.4 to 0.7, the model showed a breach on the eastern end of the berm during the 2-year flood and flooding behind the length of the berm, with the berm being overtopped and inundated from upstream during the 100-year flood. It was noted that the berm has done a good job of erosion protection but was starting to fall apart. While the berm has been effective for erosion, John did not think that it was high enough to provide true protection for extreme flooding events. The berm was serving the purpose of mitigating channel migration towards town and the US-101 Bridge, but there was potential channel migration risk upstream of the berm extent into the old channel scar. 4: At the low area between the Dosewallips State Park Campground and US-101, the model showed some flooding during the 2-year flood event, and significant flooding and impoundment of water during the 100-year flood. One of the local residents recalled canoeing across the campground when the entire area flooded in the year 2000, but that has not happened again since. Climate change projections included impacts from sea level rise and an increased magnitude and frequency of peak flow events. The resulting influence on flood risk involves higher flood depths and slightly larger extents, which have a higher magnitude closer to where sea level rise has an influence. The majority of existing buildings and the main transportation route in and out of town are likely to be impacted by sea level rise over the next century. John gave an overview of the assessment findings, which included areas of flood risk at the overflow channel north of the fire station, impoundment behind US-101 at the north end of town and around the Community Center, the river left berm upstream of the US-101 Bridge, and impoundment between the campground and the US-101 road prism. Areas of channel migration risk included a low risk of channel avulsion at the upstream end of the flood channels, a moderate risk of erosion and flanking at the upstream end of the berm, and landslide potential raising the risk of significant channel change. Sea level rise will increase flood depths impacting Brinnon infrastructure and US-101. Subsequent meetings may include conversations about upcoming work on the Rocky Brook reach, fish and fish habitats, and more discussion on flooding and erosion. Tami Pokorny noted that the assessment would be available to the public after the fish sections have gone through final review, and that John’s presentation would be posted on the Dosewallips River Collaborative website. George Terry agreed to discuss Federal Emergency Management Agency and related flooding regulations at the next meeting. John mentioned that NSD had done similar studies and project designs for multiple rivers on the Peninsula and the north Pacific coast. The group asked if NSD would be willing to present other work they had, what had worked and what had not been effective, and introduce them to landowners who had had projects done on their properties. John agreed that the NSD would be happy to do so. 4 Next Meeting and Agenda There was no follow-up meeting scheduled, but the group discussed meeting again within the next couple of months. Public Comments A landowner expressed concern that the County would be installing log jams and other salmon restoration projects that would make flooding and erosion worse. He said the salmon seemed to be accessing the river fine, and that he would like to see fishing regulations enforced. Other landowners expressed similar concerns. John Soden noted that projects were not allowed to cause flooding or increase erosion risk. While a full spectrum of projects would be researched, any project designs will be presented to and approved by the community. Adjourn at 10:38 AM Summary by Rebekah Brooks (Rebekah Brooks Contracting)