The South Fork of the Boise River Models and Data Details
South Fork Boise Watershed Collaborative
The South Fork Boise Watershed Collaborative is a group aimed at identification, prioritization and implementation of improvements to the South Fork Boise Watershed between Anderson Ranch Dam and Arrowrock Reservoir. A general spatial overview or the group can be found in the collaborative's overview StoryMap https://arcg.is/1SCva82. More information can also be found at www.southforkboise.org. This StoryMap will host the more complex spatial GIS information, models and imagery for the collaborative. If you would like to provide input or be involved in the process please reach out to Anthony Prisciandaro at Anthony.Prisciandaro@tu.org.
South Fork Boise Beaver Dam Analog (BDA) Conservation Potential. This is a model that predicts the best locations for BDAs. Willow Creek BDAs and Beaver Dams. Click on a camera icon to see details and a photo of BDAs or actual beaver dams in the Willow Creek Drainage. Click on the photo in the details to enlarge. BDAs were installed on Idaho Department of Lands property in multiple years. Additional structures are located just upstream of the area documented here. The first year of installations is documented at https://bda-explorer.herokuapp.com/projects/178 .
Potential Side Channels to reconnect at 300cfs. Rankings (numbers 1-7) are to prioritize which side channels to investigate and survey during the detailed site survey by IDFG and the TU Science Team.
South Fork Boise Floodplain and Valley Extent. Navigate around the map to see areas where the accessible floodplain is narrow vs wide. Note that most of the potential side channels are associated with areas of wide floodplain.
Potential fence line relocation to protect bull trout critical habitat in Little Rattlesnake Creek. There is currently a gate that allows access to an official trail (purple), but also allows access to a closed road that parallels the creek. Fence would be removed (red), installed (green) and remain the same (black).
Campsites along the roadside reach of the SF Boise River. Click on individual points for more information and a photo. There are approximately 60 sites with some large enough for multiple tents/campers. Occupancy surveys of these sites will provide information on campsite preference and availability.
High Flows wet floodplain and camping areas
High flows inundate some existing dispersed camping along 121R. Move the slider back and forth to see differences between 9/15/2021 (704cfs) on the right and 5/21/2023 (5,760cfs) on the left. For reference, maximum flows in 2017 (9,057cfs) are the highest on record since 1956. Some dispersed campsite locations noted by the red dots were fully inundated in 2023. Periodically inundated campsites make easy access to toilet facilities important.
Location of a potential new boat ramp to supplement current Tailwaters and Reclamation Village ramps. Blowouts after the 2013 fires created a new rapid just below the Tailwaters ramp. Recreationists are creating user made ramps to avoid this rapid. Reclamation Village is often busy and can be difficult to back a boat in when the parking lot is full.
Changes after Anderson Ranch Dam construction
Move around to find your area of interest where data is available for comparison between 1957 black and white imagery and 2021 imagery. Anderson Ranch Dam was completed in 1950.
One area showing changes in river channel between 8-2-1957 (1500cfs) and 9-15-2021 (659cfs). Most areas of the river did not see this much difference but there was overall channel narrowing even if the main path did not migrate. Anderson Ranch Dam was completed in 1950. It reduced peak flows as well as sediment inputs. Similar to other tailwater rivers this has caused a reduction in habitat complexity, narrowing and downcutting of the channel as well as changes to the riparian plant community.
Move around to find your area of interest where data is available for comparison between 1939 black and white imagery and 2021 imagery. Anderson Ranch Dam was completed in 1950.
Changes in the river channel between 6-29-1939 (516 cfs pre-Anderson Ranch Dam) and 9-15-2021 (659cfs).
Photo Point Locations are from a 2015 Eagle Scout Project to monitor post fire recovery using citizen science. The collaborative is currently working with the Forest Service to get approval for deploying remote equipment to monitor temperature, flow and recreation use.
