Engineering Services for a Storm Drain Master Plan North Willows County Service Area

The Glenn County Public Works Agency is soliciting proposals from qualified engineering and planning firms to develop a Storm Drain Master Plan for the Northeast Willows County Service Area. The plan will assess existing storm water infrastructure, identify deficiencies and future needs, and propose system improvements to ensure optimal drainage performance and flood protection throughout the service area. The scope of services includes project management and coordination, data collection and review, flow monitoring, hydrologic and hydraulic model development, capacity improvement project development, and long-term capital improvement plan development. The consultant will be required to submit a technical proposal and a sealed fee proposal. The contract will be based on actual cost-plus-fixed fee, and the fixed fee is not adjustable during the life of the contract. • The storm drain system in the NWCSA generally flows from the retention basin west of I-5 toward the GCID Canal and eastward. • The system has three major discharge points: a primary outlet that flows through the siphon under the GCID Canal into a ditch east of Willows Cemetery, and two outlets that discharge directly into the GCID Canal. • The consultant will be required to develop a hydrologic and hydraulic model reflective of actual conditions to quantify flows in the storm drain system and identify capacity deficiencies and improvement needs. • The consultant will be required to evaluate the existing storm water collection system hydraulic capacity performance and estimate flood control level of service. • The consultant will be required to develop alternative options to consider for addressing flooding occurrences in the hydraulic model.