Elephant Habitat Overview

The Elephant Scenario is used to understand how "near future" habitat and flows, alongside hatchery and harvest actions, will benefit salmon.

• Modeled flows represent planned Habitat + Spring flow actions, which are expected in the near future, and proposed as part of the Healthy Rivers and Landscapes Program. However a scenario that reflects the Healthy Rivers and Landscapes proposal in full could not be accomplished in time for the October workshop, and is proposed for a future funding opportunity. Documentation can be accessed at: https://ceqanet.opr.ca.gov/2023060467/2.

• Habitat projects proposed under the Healthy Rivers and Landscapes Program and are outlined below. More information on modeling can be found in the Elephant Habitat Modeling Details section.

Habitat modifications for the Elephant Scenario

The following habitat modifications were made as part of the Elephant scenario. Commitments are outlined in Appendix 2 of the Memorandum of Understanding.

Commitment	Modeling details
20,000 acres of additional floodplain habitat in the Sutter Bypass, Butte Sink, and Colusa Basin	After producing habitat estimates for the Sutter Bypass using the CalSim3 flows, Sutter Bypass habitat was raised to 20,000 acres for the months of December, January, and February.
20,000 acres of fish food production in the Sutter Bypass, Butte Sink, and Colusa Basin	Prey density was raised to "max" for the Sutter Bypass and Colusa Basin (Lower-mid Sacramento and Lower Sacramento watersheds in the model). Additionally, the available acreage for dry side floodplain for Sutter and Colusa basins was calculated using these data. The proportion of the committed 20,000 acres those acreages provide was calculated and then used to scale instream habitat for those watersheds for the months of January and February.
Predation reduction	Remove 1 contact point on Feather River, 9 contact points on the Upper Sacramento River, 1 contact point on Butte Creek, and 1 contact point on Antelope Creek.
American River	The flow-to-habitat curve used for instream and floodplain habitat is the same used in the Scientific Basis Report (see Chapter 5).
Feather River	The flow-to-habitat curve used for spawning and instream rearing habitat for the low flow channel (LFC) is the same used in the Scientific Basis Report (see Chapter 5).
Mokelumne River	The flow-to-habitat curve was provided by the Mokelumne River for spawning, rearing, and floodplain habitat is the same used in the Scientific Basis Report (see Chapter 5).
Tuolumne River	An updated VA flow-to-habitat curve was provided by the Tuolumne River for spawning and rearing habitat.
Yuba River	An updated VA flow-to-habitat curve was provided by the Yuba River for instream and floodplain habitat.