Gomes Lake / Harding Drain Improvements

Updated on 2/4/2022: Short Project Description, Long Project Description, and Project Cost

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. These include facilities to enable dry-docking of currently submerged pumps, improvements to closure valves, and development of redundant power supply to Gomes Lake pumping plant to prevent power failure of critical infrastructure in an emergency scenario.

Long Project Description:
DWR asked for clarification on which levee was subject to erosion hazards. [Note: levee erosion protection or repair is not part of the project description.] It is the project levee adjacent to the Gomes Lake Bypass Channel, which enters Gomes Lake from the south.

Flood fight operations are necessary for two distinct structures in this district; the project levee and the Gomes Lake dike. Failure of either structure could flood portions of the district damaging property and potentially critical assets. Failure of the Gomes Lake Dike could also create additional threats to the stability of the project levee. The emergency response organizational structure for coordinating these two operations is unclear as well as the process for resolving any conflicts between each operation that may arise. At least no written protocols or procedures addressing these issues were identified.

In 1997, water elevations are reported to have reached within 1’ of the crown of the project levee at locations. The District levee experienced numerous boils north of Gomes Lake at an extreme bend in the levee and additional boils and the failure of a section of the levee back slope adjacent to the Gomes Lake Bypass Channel. While the project levee did not fail, the Gomes Lake Dike did subsequently fail.

The open ditch Gomes Lake Bypass Channel runs immediately adjacent to the landside toe of the project levee for more than one-half mile. It is obviously a serious design flaw to have a large open ditch with running water immediately adjacent to the landside toe of a flood control levee. It prevents adequate levee inspection and is a threat to levee stability. A constriction in the Channel and periods of rapid drawdown of Gomes Lake can create a 300 cfs flow creating the potential for damage to the project levee.

Project Status	Pre-planning
Project Cost	$1,847,000
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.