Description: PWA and Griggs (2004) defined three risk categories to Monterey Regional Water Pollution Control Agency (MRWPCA) facilities between Marina and Wharf II. These risk categories were determined by assuming that current long-term historic erosion rates would continue over the next 50 years. For this Coastal RSM Plan assessment of critical areas of erosion, the historic erosion rate results of Thornton et al. (2006) are used with an increment of approximately 20% added to the erosion rate for potential increases due to future sea-level rise. The risk categories are: Low risk - facilities with a low probability of being impacted by erosion over the next 50 years. Moderate risk - facilities not likely to be affected by chronic erosion over the next 50 years, but potentially susceptible to short-term storm event erosion within the planning horizon. High risk - facilities that are located seaward of the shoreline position anticipated in 50 years or presently vulnerable to short-term event-based erosion. A high risk designation also applies to facilities with shore protection (presently or approved), where erosion isimpacting public safety and access, and reducing the shoreline recreational value.Future erosion rates could be lower if beach-sand mining ceases. In this case, moderate and high risk facilities would have a larger buffer zone of protection, and management action could be delayed beyond the time lines recommended in this Coastal RSM Plan. Conversely, erosion rates may increase if future sea-level rise accelerates over the predicted estimates (Section 2.4), and management may need to be more immediate.All the facilities identified as at high or moderate risk of erosion were then assessed as to their future value. This assessment is based on the SMBCEW (2006c) evaluation of the economic (potential loss of facility), environmental (potential loss of habitat), and safety and human health (potential loss of life) consequences of loss of the facility. The facilities are designated as high consequence, moderate consequence, or low consequence. The shapefile was compiled by PWA and submitted to CSMW as part of the Southern Monterey Bay Coastal Regional Sediment amanagement Plan (AMBAG, 2008).
Copyright Text: Philip Williams & Associates, Ltd (PWA), Association of Monterey Bay Area Governments (AMBAG), Coastal Sediment Management Workgroup