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HomeMy Public PortalAboutBCAStrategyOutlineDRAFT Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline June 15, 2016 Horsley Witten Group, Inc. on behalf of the Brewster Coastal Advisory Group Page 1 Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline 1. I NTRODUCTION Brief overview of Brewster’s coastline resources Introduction of the Brewster Coastal Advisory Group (BCAG) Board of Selectmen’s Charge to the BCAG 1.1 Scope This Strategy focuses on Brewster’s town-owned landings, beaches, parking areas, and publically-owned lands in the immediate vicinity of town landings and beaches. The critical steps involved in developing this Strategy were: 1. Conducting a vulnerability assessment to identify areas of risk from increased storms and storm surge and sea level rise (SLR), such as erosion prone areas, areas prone or likely to flood under specific storm surges, and wetlands and natural resource areas that can absorb storm/surge energy. • Develop maps and oblique visualizations showing the predicted extent of impact from these SLR scenarios and storm surge estimates. • Combine the mapping with data obtained from the Town’ GIS database on land use, natural resources, parcels, and public infrastructure to identify the degree to which infrastructure and natural resources are vulnerable relative to the estimated levels of erosion and SLR. • Review the Town’s past assessment of impacts of SLR on groundwater to identify additional coastal impacts. 2. Identifying a range of adaptation opportunities for the Town to consider based on current and predicted future conditions along the coast and public consensus. These adaptation opportunities may include, but are not limited to: retreat of natural and built resources, wetland migration, regulations on future development, land acquisition, retrofits of existing properties and structures, and alternative access. 3. Developing a matrix of adaptation strategies identifying the magnitude of costs and level of benefit, e.g. no regrets, low regrets, and climate-justified. 4. Identifying potential trigger points for action (e.g. what condition or threat triggers a specific action). DRAFT Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline June 15, 2016 Horsley Witten Group, Inc. on behalf of the Brewster Coastal Advisory Group Page 2 1.2 Purpose of the Document Many difficult management decisions are needed to adapt to future climate change impacts. The Brewster Coastal Adaptation Strategy will provide guidance to the Brewster Board of Selectmen, town departments and regulatory boards and commissions and organizations, and individuals that manage coastal areas and resources within the Town. The Strategy is intended to lay the groundwork for future discussions and the development of an implementation plan- the Brewster Coastal Resource Management Plan. Furthermore, the Strategy will set the stage for the legal and regulatory changes that are likely to be necessary to implement adaptation approaches. Prior to the completion of the Management Plan, the Strategy can guide the incorporation of climate resilience into proposed Town projects. Finally, the document may assist the Town in identifying and applying for additional funding to improve the Town’s climate resilience. 1.3 Guiding principles for adaptation Decisions made about the future of Brewster’s public coastal areas should seek to uphold the following community values, priorities, and desires (listed in no particular order): • Access: Maintain and expand the opportunities for beach-goers of diverse ages, preferences, and physical capabilities to access Brewster’s public beaches year-round. Consider the access needs for parking during peak summer demand as well as those of bikers, walkers, those with limited mobility and users of wheelchairs, families, commercial and recreational shell-fishermen, and nearby neighbors, and the safety needs of providing and balancing this access for all. • Natural Beauty: Protect and maintain the natural beauty, non-commercial, peaceful, quiet, spacious, and “small feel” of Brewster’s coast, beaches, and coastal neighborhoods, and safeguarding their long-term importance for the Town and its residents. • Science-based, innovative and realistic: Seek long-term solutions based on the best available science that are innovative, realistic, and achievable, that work along with nature and build climate resiliency today and into the future, and that are both environmentally and fiscally sustainable. • Holistic: Protect the environment of the beaches and the whole coastal system, including habitat, salt marshes, and other ecosystem services. Seek actions appropriate to coastal projections and community needs that build on and enhance the coast as well as the ecosystem as a whole. • Adaptive and Consensus-Based: Employ flexibility and adaptive planning, with continuous feedback loops - with public input and seeking community consensus throughout – to best respond to of changing technologies, opportunities, and scientific uncertainties. 2. O VERVIEW OF C OASTAL T HREATS Brief introduction to Brewster’s tidal range and historical impacts to the shoreline DRAFT Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline June 15, 2016 Horsley Witten Group, Inc. on behalf of the Brewster Coastal Advisory Group Page 3 2.1 Erosion Provide historical erosion rates (CZM coastline change report), show map of 1951 – 2009 coastline change, and provide range of erosion/accretion rates along the Brewster shoreline 2.2 Storm Surge Summarize historic data on storm surges (presented to BCAG), including source/reference 2.3 Sea Level Rise Identify data sources for information, and selected scenarios (as presented to BCAG in initial meetings) 3. V ISUALIZING THE S HORELINE AND T HREATS 3.1 Maps Description of data used for mapping purposes, method for representing SLR and storm surges. Town-wide map showing SLR (MHW, +2ft, +4 ft, +8 ft) and historic coastal erosion 3.2 Other Visuals Graphic imagery developed from drone fly-overs and GIS information Link to online video representing SLR at Paine’s Creek. 4. O VERVIEW OF C LIMATE C HANGE I MPACTS ON B REWSTER'S C OAST 4.1 Impacts to Town Landings Landing by landing information – matrix (visual landing profiles may be provided as an appendix to this strategy) 4.2 Town wide issues An analysis of climate impacts on other resources, with a focus on impacts to Town-owned properties. Some of this is based on previously developed information, such as for septic systems and mapped stormwater facilities. • Wetlands – identify coastal wetlands potentially impacted by SLR • Septic systems and groundwater level increases – brief discussion based on evaluation and mapping conducted for Brewster’s Integrated Water Management Plan • Water lines – identify water lines that may be impacted by SLR (e.g., street/road name, length) • Stormwater – identify catch basins that may be impacted by SLR (based on available stormwater infrastructure data) • The Flats – determine low tide impacts from SLR DRAFT Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline June 15, 2016 Horsley Witten Group, Inc. on behalf of the Brewster Coastal Advisory Group Page 4 5. S TRATEGIES FOR A DAPTATION 5.1 Adaptation at town landings In general a range of options are being considered based on previous workgroup discussions. More information is likely to be generated in future meetings. Basic strategies include: • No action • Short term maintenance issues (overwash/debris management) • Adapt and maintain access as possible Landing-by-landing adaption strategies discussed to date are presented below. These options represent solutions identified by the BCAG based on today’s knowledge, and may be updated in the future as new information becomes available. Wing Island • Consider providing offsite parking • Install bike racks at Drummer Boy • Enhance access to Wing Island (e.g., raised boardwalk) • Actively manage the salt marsh and promote a transitioning environment (allow marsh retreat) Paine’s Creek • Replace footbridge • Continue beach nourishment • Evaluate opportunity to introduce marsh grass to protect the beach • Consider shuttle, given beach popularity, potential pilot/trial at this landing from various parking areas (e.g., Lemon Tree plaza) • Explore opportunity for a bike share from the same locations • Create a mixed use lane on Paine’s Creek Lane • Mant's Landing • Continue maintaining dune • Replace pavement with articulated concrete pads • Consider a shared shuttle with Paine’s Creek given proximity and beach popularity • Landing provides good access for heavy vehicles which should be maintained • Elevate back of lot to improve drainage Saint's (limited threat for some time) • Beach nourishment after storm events • Re-grade parking lot to redirect drainage away from beach Little Breakwater • Limited expansion opportunity available • Ongoing beach nourishment • Maintain/support the stairs, particularly after storm events DRAFT Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline June 15, 2016 Horsley Witten Group, Inc. on behalf of the Brewster Coastal Advisory Group Page 5 Breakwater • Ongoing beach nourishment • Maintain sand fencing and plantings to protect dune • Evaluate shuttle carefully (e.g., can the beach handle more people? Would a turn-around work for the shuttle? Point of Rocks • Install bike racks • Maintain access for fishermen • Nourish and plant primary frontal dune following coastal storms Ellis (Note: The Town has plans for this fall to increase resiliency and improve stormwater management) • Construct at-grade handicap walkway • Maintain access for fishermen • Nourish and plant primary frontal dune following coastal storms Spruce Hill • Add parking (It is a long walk to the beach, but there is good frontage). Note: additional parking may become available if building use changes • Improve pathway Linnell • Beach nourishment to maintain platform • Relocate northern portion of parking lot away from dunes Crosby • Improve tidal restriction/ flow • Develop alternate access through state property (as long as it remains open to the public). Note: an existing proposal exists • Consider shuttle (may not work) • Educational efforts with NSP campers 5.2 Town-wide strategies Sample strategies for evaluation and prioritization are listed below: (Note: while the BCAG has had preliminary discussions about alternative transportation, further discussion is needed about the inclusion of the other town-wide strategies offered here). • Evaluate alternative transportation to town landings: o Access by shuttle: beach and key locations along 6A o Bike access (bike strategy) • Work with bikeways committee to improve bike access and ensure sufficient bike racks are available at each landing • Continue to provide kayak racks at appropriate locations and expand as demand requires, while considering their impact to parking and infrastructure • Identify potential future town access points to the coast (such as through State land between Linnell and Crosby Landings DRAFT Brewster Coastal Adaptation Strategy – DRAFT Annotated Outline June 15, 2016 Horsley Witten Group, Inc. on behalf of the Brewster Coastal Advisory Group Page 6 • Work with the Open Space Committee to evaluate the acquisition of vacant parcels within 100-year flood and localized velocity zones, or to allow wetland protection/migration • Identify areas that can allow for wetland retreat/expansion (wetlands provide a storm buffer and help contain surges) o Identify and protect undeveloped areas upgradiant from coastal wetlands to allow for wetland migration and buffer intact ecosystems o Develop high resolution elevation models to identify and prioritize areas that may become wetlands in the future • Consider updates to Brewster wetlands bylaw to add performance standards for wetland migration • Develop coastal overlay district, regulating size, setback of buildings; erosion control measures. For example, consider a recovery/reconstruction ordinance. This may include regulations on length of time existing coastal structures may be maintained (e.g., limits on extent of maintenance- if more than X% damage allow one more repair and then retreat or elevate structure) • Consider long-term management of hardened structures along the coastline • Evaluate incentives for relocating existing structures out of areas that are subject to future sea level rise and/or high rates of erosion (link to hazard mitigation plan) 6. R ECOMMENDATIONS Sample recommendations for evaluation are listed below: • Maintain ongoing community engagement on projects and decisions within the Brewster coastal zone • Further evaluate the impact of SLR on the offshore flats based on the data developed as parto f this study. How will ongoing sediment migration change the location and elevation of the flats • Evaluation of options and feasibility for shuttle access to town landings • Research/Identify funding opportunities through: o FEMA grant process for Hazard Mitigation grant Program, Severe Repetitive Loss, etc… which requires FEMA-approved Hazard Mitigation Plan (see second recommendation below), o CZM Coastal Resiliency Program • Finalize Hazard Mitigation Plan • Others to be determined