Instream Spawning and Rearing Habitat

Details:

Habitat modeling is not available for several tributaries of the Upper Sacramento River. These tributaries share similar hydrologic and geomorphic conditions. In consultation with Mark Gard at the California Department of Fish and Wildlife, regional approximations of instream spawning and rearing habitat were developed for tributaries without habitat modeling. The regional approximation for instream rearing habitat uses the mean weighted usable area (WUA) at a subset of flow values from Battle Creek, Butte Creek, Clear Creek, and Cow Creek. For instream spawning, the regional approximation uses the mean WUA at flows from Battle Creek, Butte Creek, and Clear Creek.

The following table shows watershed areas and channel widths for all of the watersheds used to create regional approximations.

Watershed Area (sqkm) Width (m)
Battle Creek 957 22.50
Butte Creek 2123 15.20
Clear Creek 645 18.00
Cottonwood Creek 2444 28.25
Cow Creek* 1107 8.50

*Cow Creek is not included in regional approximation for spawning.

The following table shows watershed areas and channel widths for watersheds without spawning and/or rearing habitat modeling.

Watershed Area (sqkm) Width (m)
Antelope Creek 508 15.8
Bear Creek 649 4.3
Big Chico Creek 930 14.8
Cow Creek* 1107 8.5
Elder Creek 358 8.6
Mill Creek 334 14.3
Paynes Creek 243 6.3
Stony Creek 2021 19.6
Thomes Creek 758 12.9

Spawning and Rearing Data

The instream spawning and rearing habitat data described above for Fall Run Chinook Salmon (FR) are combined for use in the Decision Support Model (DSM) in the following format. Units are in square feet per 1000 feet.

Header Descriptions: flow_cfs = flow in cubic feet per second, FR_spawn_wua = Fall Run Chinook Spawning WUA, FR_fry_wua = Fall Run Chinook Fry WUA, FR_juv_wua = Fall Run Chinook Juvenile WUA, watershed = section of stream modeled for CVPIA SDM
flow_cfs FR_spawn_wua FR_fry_wua FR_juv_wua watershed
50 5157.882 13123.57 11114.86 Upper-mid Sacramento River Region
75 5279.603 12408.41 12034.16 Upper-mid Sacramento River Region
100 5306.260 11471.74 12448.54 Upper-mid Sacramento River Region
125 5281.266 10641.96 12463.12 Upper-mid Sacramento River Region
150 5244.334 10026.15 12230.09 Upper-mid Sacramento River Region

… with 18 more rows

Spawning WUA

The following plot shows the WUA in square feet per thousand feet for Chinook Salmon used for Upper Sacramento River tributaries without adequate habitat modeling. These area per length rates are multiplied by the total spawning reach length mapped by the Science Integration Team (SIT) to estimate habitat area.

Rearing WUA

The following plot shows the rearing WUA in square feet per thousand feet for Chinook Salmon used for Upper Sacramento River tributaries without adequate habitat modeling. These rates are multiplied by the total rearing reach length mapped by the SIT to estimate habitat area.