A well-maintained fish screen will save you money by extending the screen's life. Gravity diversions should be inspected weekly for leaves and debris and to confirm that the screen is working properly. The fish bypass pipe should also be inspected to confirm there are no obstructions and fish can safely migrate to the river. Pump screens are designed to operate under specific conditions and shouldn't require major maintenance during irrigation season, as long as those conditions are met.
WDFW recommends these basic maintenance tasks:
- Check the water flow in the bypass channel. Adequate bypass flow assures that fish are safely and rapidly moved from the fish screen back to the river. Bypass water also flushes floating debris, sand, and silt to the river, which reduces cleaning and maintenance at the screen and in the canal. The NMFS manual provides minimum water elevation requirements based on bypass pipe diameter.
- Remove debris from the screen, trash rack, around the pump, or in the bypass channel.
Assess your diversion site conditions. Has dry weather, a rain event, or ice changed how your diversion functions?
- If water flow is lower than normal, the screen may need maintenance. Check your system for any blockages and refer to your HPA for any allowed actions to increase flow.
- If water flow is higher than normal, then the head gate may need adjusting to reduce flow.
- Verify that your screen is submerged to the proper depth for your screen type.
- Repair screen when damaged to ensure proper operation and fish protection.
- Check screen seals and mechanical parts and grease as needed.
Since 1984, WDFW has offered service contracts to landowners for screen maintenance. When you have a service contract, WDFW will respond immediately to evaluate and repair any problems. Many owners find this an economical and easy way to meet their maintenance obligations.
Contact our screening experts to learn more about proper maintenance and how we can help.