The Sea Also Rises,*

- Any SLR adaptation and mitigation regional planning group will incur ongoing costs in salaries, benefits, and overhead that will require the political entities surrounding Humboldt Bay to agree to cost sharing. Response to Finding 3 – The Arcata City Council (Council) disagrees with this finding. Council cannot commit to cost sharing and/or allocation of staff time for a regional planning group without any information on the proposed group. Council agrees immediate and ongoing commitment to adaptation and mitigation is essential to addressing the threats posed by sea level rise. Council also agrees regional collaboration is essential to effective planning and implementation of adaptation and mitigation measures. For example, the City of Arcata (City) is actively participating in the development of the Humboldt Regional Climate Action Plan to leverage staff time and resources and ensure a collective, wholistic, robust response to greenhouse gas emission reduction. However, decisions on the region's approach(es) to collaboration on the issue of sea level rise should be made collectively by regional stakeholders. Given the existing regulatory complexity around Humboldt Bay and the diverse array of local, state, federal and tribal stakeholders involved, it should not be assumed creating a new regional governmental entity will be the most effective, efficient or just approach to regional collaboration.

- The costs associated with SLR mitigation efforts will be significant and will require the diligent pursuit of Federal, State, and Public funding sources. Response to Finding 4 – Council agrees with this finding. The City has been, and will continue to diligently pursue funding sources for sea level rise adaptation work. For example, the City worked tirelessly to secure funding from a variety of local, state, and federal sources for the Elk River Estuary and Tidal Wetlands Enhancement Project, a 114- acre tidal marsh habitat restoration project currently under construction in southern Arcata. This, and previous wetland restoration projects within City watersheds, such as the Martin Slough Enhancement Project, will significantly increase the City's flood capacity and aid in future habitat migration and resilience as sea levels rise. The City advocates for state and federal granting agencies to ensure grants are earmarked and available for rural locales and targeted at all project stages so the City can successfully navigate from project development to construction. The City also calls on state and federal permitting agencies to simplify environmental regulatory processes for restoration and climate resilience projects.

– The decade of studies that defined the areas and physical assets vulnerable to SLR around Humboldt Bay by mid-century clearly indicate there is an urgency to start developing and implementing solutions. Response to Finding 5 - Council agrees with this finding. The City is already implementing adaptation solutions, while working towards a comprehensive, phased approach to sea level rise adaptation along Arcata's shoreline, with short-, mid-, and long-term adaptation triggers for vulnerable areas and assets based on observed sea level rise thresholds. The City has been actively planning for sea level rise since 2013. In that time, the City has held more than 40 public meetings on the topic, secured multiple grants to study the sea level rise rates, vulnerability, effects, and best policy. This work resulted in background reports shared with the Community in 2014-2016, two risk assessments in 2018, including Sea Level Rise in the Humboldt Bay Region" (Northern Hydrology & Engineering 2018), the "City of Arcata Sea Level Rise Vulnerability Assessment (Laird 2018)", and an ongoing effort with a Thriving Earth Exchange Fellow that is working on more detailed habitat mapping to inform restoration and mitigation decisions in the future. In addition, the City has secured two Coastal Commission grants to develop a comprehensive update to the Local Coastal Program, which includes significant progress moving the background developed previously into policy.

– Former industrial and other contaminated sites around the Bay are susceptible to SLR. As such, SLR could push the contamination into wetlands, creeks, and even Humboldt Bay itself, making it harder to mitigate and clean up. Response to Finding 8 - Council agrees with this finding. The City understands the threat of mobilization of soil and groundwater contamination as a result of sea level rise. The City has secured an approximately $360,000 Brownfields Cleanup Grant from the U.S. Environmental Protection Agency (EPA) to clean up the former Little Lakes Industries site. The City has also secured a Technical Assistance grant from the EPA to evaluate former mill sites to ensure dioxins and other contaminants are identified and cleaned up as necessary. In addition, the City's LCP zoning provides strategic land use incentives for industrial sites to convert to other cleaner uses, thereby eliminating the risk through land use.

- Research studies of SLR impacts around Humboldt Bay indicate that if no action is taken by 2050, monthly maximum high tides will overtop bay barriers and flood existing infrastructure, wetlands and low-lying communities. Response to Finding 9 – Council agrees with this finding. However, it is important to note areas around Humboldt Bay are already vulnerable to significant flood damage at current water levels, segments of bay barrier have already overtopped, and additional segments will be vulnerable with different amounts of sea level rise, with uncertainty around when sea levels will be reached and overtopping will occur. As a result, the City is already taking actions to adapt to sea level rise, and timing implementation of future actions based on observed sea level rise thresholds. It is also important to note low-lying areas around Humboldt Bay are not only going to be affected by overtopping of bay barriers by tidewaters, but also by rising and potentially emergent groundwater, and by reduced stormwater drainage capacity, especially when rainfall events coincide with high ocean water levels. As a result, sea level rise adaptation will be more complex and varied than solely relying on elevation and fortification of tidal barriers. Council supports adaptation responses with multiple benefits, such as the use of living shorelines and dredged spoils deposition to allow habitats to migrate/adjust to rising sea levels, and the use of public access trails as shoreline protection. Council also believes the City's work to increase affordable and infill housing development outside of the hazard zone is a critical component of the region's sea level rise adaptation response. Given the amount of work necessary between now and 2050, prioritization of adaptation measures will be critical. The City will strive for thoughtful consideration of the distribution of environmental risks and adaptation benefits in setting priorities, and the meaningful participation of all groups in the decision-making process.