WOOD RODGERS, INC. (#2026291) - Laserfiche WebLink

City of Pleasanton | Stormwater System Management Plan | PWD 25.601 | PAGE 19 Flood Risk = Likelihood x Consequence Task 5 | Development of a Capital Improvement Plan A capital improvement plan (CIP) will be developed to determine locations, schedules, and resources (land, labor, capital) for agency‐ wide improvement projects identified to reduce flood risks and restore drainage facility useful life. Task 5.1 – Risk for Condition and Capacity Deficiencies Wood Rodgers will develop improvement project prioritization criteria based on flood risk, cost‐effectiveness, social equity benefits, health and safety, and traffic interruption considerations. The ranking developed from the prioritization criteria will then be used to develop an implementation schedule for a 10‐year CIP. The practice is to maximize the involvement of City staff in all critical decisions in selecting appropriate criteria and prioritizing projects. A Workshop with City staff shall be conducted to discuss and gain buyoff on the criteria and methodology. FLOOD RISK Where numerous projects are required to address deficiencies, we have implemented more formal risk models that quantify the likelihood of capacity exceedance/failure and the associated consequences. Projects intended to address the highest risks in the storm drain system with the lowest cost will be given the highest priority in the CIP. ▪The likelihood of flooding based on the simulated facility capacity ▪The associated consequences measured in flood damages or floodplain areas The drainage facility flood risk for each of the deficient systems is calculated using the following formula: The calculated flood risks provide standard and quantifiable values to assist the City to prioritize improvement projects for capacity deficient drainage systems. Wood Rodgers will use the calculated flood risks and the respective improvement project capital costs to determine the cost effectiveness for the major deficient drainage systems for improvement project prioritization. This flood risk model provides floodplain extents, flood frequencies, flood damages, and benefit‐cost ratios (BCR) that can be used to support future flood mitigation grant applications. SOCIAL EQUITY In addition to flood risk and cost‐effectiveness considerations, Wood Rodgers proposes incorporating equity benefits into improvement project prioritization. Prioritizing projects with equity considerations promotes fair resource allocation, enhances social cohesion, garners public support, ensures legal compliance, and fosters long‐term economic benefits. The equity framework consists of six themes that cover broad areas of people’s lives, including: 1) economy; 2) education; 3) public health; 4) housing; 5) public safety; and 6) neighborhood and civic life. TRAFFIC INTERRUPTION Traffic interruption is another risk and a source of economic loss that local communities endure during flooding events. The risks of emergency access isolation, vehicular accidents, and pedestrian access restrictions are critical concerns for the community. Lost wages and business interruptions represent additional economic impacts. A metric that has been used and accepted by FEMA in grant applications is Average Daily Traffic (ADT) counts. Flooding in areas with higher ADT values has a greater impact on transportation than does flooding in areas with lower ADT values. A higher ranking will be assigned to deficient storm drain systems with a high ADT, while a lower ranking will be assigned to those with a low ADT. In addition to the prioritization criteria above, Wood Rodgers will work with the City’s staff to assess the environmental permitting requirements, rights‐of‐way, encroachment permits, and utility conflicts for the improvement projects. Deliverable(s): Project flood risk | Criteria and Methodology Workshop EXHIBIT A Docusign Envelope ID: DF86282A-2A84-404C-9F8A-A035AEFBCFF8