Environmental Projects: What the Districts Are Doing

SSJID and OID have done plenty to date to help with fish flows in the Stanislaus River. Both have participated and funded studies on the river. Both water Districts participate by providing water in the Vernalis Adaptive Management Program, a large scale and long term program designed to protect juvenile chinook salmon migrating from the San Joaquin River through the Sacramento- San Joaquin Delta. Other projects include:

Adult Salmon and Steelhead passage – Since 2003, abundance and timing of adult salmon and steelhead returning to the river have been documented using an innovative counting weir that includes underwater video and infrared cameras. The number of salmon returning each year has ranged from a low of 408 to a high of almost 8,000 chinook salmon. Low numbers in recent years have been attributed to poor ocean conditions. During the last seven years, only 16 naturally produced steelhead have been observed.

Juvenile Salmon and Steelhead Downstream Migration Monitoring – Since 1993, abundance and timing of juvenile salmon and steelhead migrating downstream have been documented using rotary screw traps. Estimates indicate that about one million juvenile salmon migrate from the rearing reach each year with exception of 2008 and 2009 when only 100,000 juvenile salmon migrated, which is directly related to the low number of spawning adults observed for those years. Juvenile steelhead numbers are generally low (13-76 per year), but the actual number of steelhead migrating is difficult to estimate and may be much higher.

Non-native Predator and Competitor Monitoring – Snorkel and seining surveys, and weir counts are conducted to determine the abundance and distribution of non-native fish species. This information is used to determine the potential impacts of non-native predators and competitors on native salmon and steelhead.

Honolulu Bar Floodplain Enhancement Project – Oakdale Irrigation District and the U.S. Fish and Wildlife Service’s Anadromous Fish Restoration Program are jointly funding a habitat restoration project within and adjacent to the U.S. Army Corps of Engineers’ Stanislaus River Parks – Honolulu Bar Recreation Area. The project is scheduled to occur in Summer 2010 and is designed to increase spawning and rearing habitat for salmon and steelhead.

Temperature Model – Since 1998, the Oakdale Irrigation District and the South San Joaquin Irrigation District have participated in a joint effort to develop the lower Stanislaus River Water Temperature model, and ongoing temperature monitoring and modeling efforts. The peer-reviewed model has been widely accepted by stakeholders in the basin as a tool for comparing the effects of proposed reservoir operations on downstream temperature conditions.

See some of these projects in action.