Flow out of Palisades Dam, now about 3400 cfs, is going up two reasons. First are Magic Valley irrigation demands, and second flood control because run-off from snow melt in upstream drainages is just beginning. Look for the flow of cold storage water to increase and thus have a negative impact on fishing for a while.
Outflow will be increased to 2,000 cfs in four hourly increments this morning and held at 2,000 cfs until at least Thursday and most likely until Friday morning. Post-freshet outflow is tentatively planned to be set at 650 cfs, but the exact figure will be determined by inflow rate. Current inflow is around 500 cfs, but I expect that to jump quickly over the next few days to 800 cfs and likely to exceed 1,000 cfs by the weekend. This will impact flow downstream to Ashton Reservoir and has purpose of helping to flush silt from the river bed.
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL
Although the shop will be under new ownership and management by June, we are planning a summer fly casting class schedule. The current weather makes it tough to give a starting date, but we will announce dates, location, fee and equipment suggestion information on this website.
It is the time of year for IDF&G to resume their South Fork Rainbow Trout suppression activity while low flow (1130cfs out of Palisades Dam) prevails. This will take place in steps throughout the river from Palisades Dam on downstream to Lufkin Bottom. Rainbows captured through electro-shocking will be transported to other waters around the region. See the schedule below and see more information on this action on: F&G begins rainbow trout suppression on South Fork Snake River to benefit native Yellowstone cutthroat trout | Idaho Fish and Game.
If you are looking to try for trout in still waters your choice right now is in the “Slim Pickings Range.” The only open waters nearby are Hawkins and Springfield Reservoirs. Hawkins is scheduled to receive a plant of about 1600 IDF&G rainbows. Give them a chance to equilibrate, and they will provide some action to supplement that from hold-overs. Springfield has been spotty in providing action with AM and evening hours being the best times.
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL
Although snow currently dominates the banks of the river and limits access, here is a soon-to-be-performed action that will impact flow and therefore fishing from Island Park Dam downstream at least to Ashton Reservoir. Normal flow out of Island Park Dam is around 200 cfs this time of the year.
The Drought Management Planning Committee (DMPC) approved a spring freshet for April 25-27. Freshets are most effective at sediment scour and thereby aquatic insect habitat improvement when flows increase rapidly, to high outflows, and last for 48-72 hours. Flows are expected to be bumped to 2,000 cfs on the 25th and remain there until morning of the 27th. This was not easy to accomplish and has been most of a year in the making. For more information on this action, visit the Henry’s Fork Foundation web site.
Updated: 2 hours ago
A high rate of streamflow for a short amount of time. Typically a natural process in rivers caused by heavy rain or rapid snowmelt.
On the Henry’s Fork, a freshet can be:
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Springfield Reservoir provides the best access these days. Early AMs and evenings seem to offer best fishing. Present midge pupa patterns at the taking depth. Some success is possible through nymphing or by presenting black or olive leach patterns and fly rod jigs.
Flow out of American Falls dam is being increased. Now about 1700 cfs. Above the reservoir access is plentiful and flows less than normal. Fishing should improve until run-off kicks in.
The USBUREC kept its word about releasing about 900 cfs out of Palisades dam throughout the winter. Yesterday they increased flow from the dam a bit to 1150 cfs. Priority is to fill Palisades Reservoir for the upcoming agricultural season, but with at least 120% of normal snow pack in the drainage above, this should be readily done. Flood control will enter into the water management picture for a while as the amount of water released will be at a rate not to add to the potential for such in the valley below.
Fishing season has begun along the river below as receding snow pack means increasing access. Exception is that all USFS roads will remain closed until May 1st because of the effects of the past winter. To date whitefish seem to be more active than trout, especially to nymphing, but that will change as the season warms. Midges (snowflies) currently provide the major insect emergences with a few skwalas showing here and there.