Gomes Lake / Harding Drain Improvements

Project Lead: Gomes Lake Joint Powers Authority

Potential Project Partners:
Turlock Irrigation District, City of Turlock, Stanislaus County, Reclamation District 2063, Reclamation District 2091

Short Project Description:
This project includes multiple components to enhance the function, reliability, flexibility and capacity of the Gomes Lake facility, which stores and drains stormwater and return flows, providing flood risk reduction behind the east bank levees of the San Joaquin River.

Long Project Description:
Currently, the pump sump area is always submerged, requiring divers for any maintenance work and to remove fallen debris that could damage the pumps during operation. Construction of a gated weir or berm in the lake upstream of the pumps would isolate the pumps so they could be de-watered. A gravity bypass could be built around the pumping plant to continue the option of gravity flow into the San Joaquin River that currently passes through the below-base pump discharges. Replacement of aging flap gates at the pumping plant discharge is also needed. The aging gates do not open fully, causing additional head loss during pumping. There may be other pumping plant facilities that need to be improved as well.

The two existing slide gates at the terminus of the Harding Drain act in a single seating direction (only closed when San Joaquin River water level is higher than the drain). Gates capable of resisting both seating and unseating head are required for flexibility. With the installation of such gates, drain water could be conveyed to Gomes Lake any time of the year. For example, this would provide the ability to exercise the Gomes Lake pumps during the summer. The existing discharge pipes are corrugated metal and are aging and are in need of repair. Replacement or slip lining the pipes would extend the life of the structure. Other improvements are needed such as installation of trash racks at the culvert inlets.

Currently, there is vulnerability in the event of a pump outage during a flood. Gomes Lake has insufficient storage capacity to accommodate such an outage, and therefore there may be risk of flooding in such an event. It would be beneficial to increase the size of Gomes Lake to create sufficient storage capacity to handle one of the three pumps to be out for a 24-hour period. The original pumps are still used in the original pumping plant. Replacement of the old pumps with more efficient and higher capacity pumps would also provide reduced risk of flooding.

Project Status Pre-planning
Project Cost $1,700,000
Project Timeframe 1-5 years
Cost-sharing No opportunities identified to date.
Multi-benefit Project Yes
Types of benefits The project would improve flood risk management and operations and maintenance.
Source of Project Turlock Irrigation District


Unique Project Characteristics:

None specified.