Studies and Research
The Water Transfers program helps to perform studies and research to provide a reliable and safe water supply for Californians. Information developed through these efforts will help the State to better manage water supplies and support greater reliability for agricultural, municipal, environmental, and industrial needs by providing more complete and reliable data for analysis and policy direction associated with voluntary exchange or transfer of water.
- Streamflow Depletion by Wells - Understanding and Managing the Effects of Groundwater Pumping on Streamflow
Giant Garter Snake
The giant garter snake is endemic to the California Central Valley and is a federal and state listed species. The giant garter snake is known to inhabit rice land and the network of canals and drainage ways that support rice production in the Sacramento Valley. The giant garter snake also resides in restored wetlands that mimic their historic habitat. The idling of rice land has the potential to impact the giant garter snake. DWR is sponsoring research to identify the potential impacts of rice land idling on the giant garter snake and to assess the adequacy of existing mitigation measures.
To date, studies have focused on the distribution of the giant garter snake in the Sacramento Valley. These studies show that the probability of occurrence of the giant garter snake is primarily related to the coincidence of two factors: 1) the proximity to historic habitat and 2) the suitability of present habitat to support the giant garter snake. These early occupancy studies have poor precision due to the small sample size and studies are continuing to improve the precision of the occurrence probability estimates. The limitation of this study should be considered in the interpretation of this information. Also of note is that probability of occurrence is the probability that one or more giant garter snakes occur at a location; one cannot infer abundance from the probability of occurrence.
- Efficacy of Trap Modifications for Increasing Capture Rates of Aquatic Snakes in Floating Aquatic Funnel Traps
- Ghost of Habitat Past: Historic Habitat Affects the Contemporary Distribution of Giant Garter Snakes in a Modified Landscape
- Literature Review of Giant Gartersnake (Thamnophis gigas) Biology and Conservation: USGS Open-File Report 2015-1150
- A Conceptual Model for Site-Level Ecology of the Giant Gartersnake (Thamnophis gigas) in the Sacramento Valley, California: USGS Open-File Report 2015–1152
- A Preliminary Investigation of the Variables Affecting the Distribution of Giant Gartersnakes (Thamnophis gigas) in the Sacramento Valley, California
- Realized Detection and Capture Probabilities for Giant Gartersnakes (Thamnophis gigas) Using Modified Floating Aquatic Funnel Traps