TM5_-_Feasibility_Assessment_for_PMF_Hennessey_Res_04Mar2019_FINAL_(2).pdf

This file is a feasibility assessment report for the Hennessey Reservoir prepared for the City of Napa, California. The document evaluates engineering and hydrological aspects relevant to long-term reservoir expansion and water supply reliability. The assessment addresses the technical foundation necessary for advancing the Conn Dam Stability Assessment, Spillway Improvements, and Long-Term Reservoir Expansion Feasibility Study. The project is structured in three phases: Phase One requires submission of a geotechnical data report to the California Division of Safety of Dams (DSOD) by December 31, 2028; Phase Two involves assessment of dam stability including deformation estimates under static and seismic conditions; and Phase Three develops a feasibility alternatives analysis report addressing identified deficiencies including known spillway deficiencies. The services sought include professional engineering, geotechnical, environmental, hydraulic, structural, dam safety, and economic evaluation services from multidisciplinary consulting firms specialized in dam engineering.

The City of Napa anticipates utilizing federal funding for design and construction phases, with the project included in the 2022 Water Resources Development Act (WRDA) under the project name Conn Creek Dam, California. The procurement will follow a Qualifications-Based Selection (QBS) process consistent with applicable federal procurement requirements under 2 CFR Part 200 and the Brooks Act principles. The selected consultant must support regulatory compliance with DSOD and assist in advancing federally authorized flood risk reduction studies through the U.S. Army Corps of Engineers (USACE). The assessment document provides technical analysis to support future environmental review, design, permitting, and construction activities.