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City of Pleasanton | Stormwater System Management Plan | PWD 25.601 | PAGE 14 Wood Rodgers will employ this customized tool to automate catchment delineation for 70 miles of storm drain pipes. The tool will encompass topographic resolutions ranging from steep valleys and incised channels to detailed curb, gutter, and street crown geometries, including the connectivity of storm drains and channels. It will be utilized to embed storm drain and channel networks into a newly‐created LiDAR Digital Elevation Model (DEM), subsequently creating sub‐catchments at the confluences of lateral storm drains and trunks, major trunk confluences, and upstream ends of storm drain systems. The catchment delineation tool will leverage the latest land use and soil maps in conjunction with sub‐catchment delineations to develop hydrologic parameters, including hydrologic soil groups, slope, impervious coverage, flow path roughness, and overland flow length. Catchments will be developed and analyzed for existing and future general plan land use (See Exhibit 11). Deliverable(s): Catchment boundaries and hydrologic parameters for 70 miles of pipes in existing and future land use conditions | Updated geodatabase Task 3.2 – Hydraulic 1D and 2D Models Wood Rodgers proposes to develop the following: 1) a detailed and fully integrated one‐dimensional (1D) model for 70 miles of storm drainpipes with a diameter that is equal to or greater than 24 inches; 2) 30 miles of open channel; 3) detention basins/lakes; 4) pump stations; and 5) a two‐dimensional (2D) floodplain model. The models will reflect the hydraulic interactions between storm drains and open channels, storm drains and a 2D floodplain, open channels and a 2D floodplain, and storm drains/open channels. The model will have enough resolution to reflect all flood water performance within the drainage facilities in the City and to understand or pinpoint the true capacity deficiency without model simplification. A detailed and accurate open channel model is crucial to understanding the true capacity and deficiencies of the entire storm drain system, and even to understanding the maintenance requirements. The Zone 7 HEC‐RAS model geometry will be imported into the ICM model to provide accurate and dynamic tailwater conditions for the storm drain systems, and also to account for any overbank spills. Detailed channel overbank elevation profiles will be constructed to reflect accurate channel and 2D floodplain interaction during overbank flooding. The detailed open channel model can also be used to assess the necessary frequency and extent of vegetation maintenance and the corresponding hydraulic impacts. Wood Rodgers will develop 2D meshes to model floodplains up to a 100‐year storm. A detailed flexible mesh will be developed and adjusted to capture the terrain resolution for street areas where conveyance and storage is important. The City’s drainage facilities include both storm drains and street networks. The interaction between the two systems should be hydrodynamically modeled to properly assess the true combined drainage capacity. This complex (accurate), and flexible model will serve as a basis for the City for years to come. Deliverable(s): Storm drains (up to 70 miles) and open channels (up to 30 miles) in 1D and 2D hydraulic models Task 3.3 – Regional Green Infrastructure and Trash Capture Device Modeling Green infrastructure (GI) and large trash capture devices are effective solutions for improving water quality and meeting Municipal Regional Permit requirements. However, storm drain master plans often overlook the hydraulic impacts and benefits of green infrastructure. At Wood Rodgers, we have access to gage data on green infrastructure and large trash capture devices and we are thoroughly familiar with the performance of these facilities. With this knowledge, we are well‐equipped to accurately assess the performance of these facilities and to clearly present this information in the capital improvement plan. Large trash capture devices typically reduce existing storm drain capacity and will be modeled to determine the impacts to the hydraulic performance with the consideration of debris clogging. The facilities will be modeled and adjusted with a debris clogging factor and reduced performance efficiency. In contrast, LIDs, hydromodification facilities, and regional stormwater capture facilities reduce runoff and increase storm drain capacity. Including these facilities will reduce the extent of capital improvements for capacity. Under Task 7.2, Wood Rodgers Team member Geosyntec will conduct a GIS analysis to identify possible locations of future citywide GI. GI facility footprints and types will be developed for GSI opportunity locations based on preliminary sizing factors. Geosyntec will also work with Wood Rodgers H&H modelers to accurately represent facilities in their model. Wood Rodgers will model and optimize the design parameters for up to two identified large trash capture devices, hydromodification facilities, or regional stormwater capture facilities. A 10% level of detail conceptual designs and construction cost estimates will be developed subsequent to the modeling efforts for project implementation or grant applications. Deliverable(s): Modeling, conceptual designs, and construction cost estimates for up to two (2) Large trash capture, hydromodification, or regional stormwater capture facilities Exhibit 11 EXHIBIT A Docusign Envelope ID: DF86282A-2A84-404C-9F8A-A035AEFBCFF8