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:
T
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.
The river below Ashton Dam is providing fishing with midge and BWO activity making for top water action during PMs. Flow is a bit below normal for the time of year. For browns and post spawning rainbows, try streamers around locations out of direct sunlight and during low light periods.
At 9 degrees F above average, yesterday was the warmest day since last October 21.Based on updated data, SWE appears to have peaked for the year last Thursday at 117% of the average peak.Natural .
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL
Good Results from a Violent Winter
During the last few years winters have been near disasters with respect to providing snowfall to restore our reginal waters to normal amounts that are beneficial for resident salmonids. Consequently, those salmonid populations have dwindled a bit, and those remaining have been relatively inactive in responding to our fly fishing efforts.
Although annoying, this winter has been the most generous in decades for providing replenishing amounts of snow. Here are some examples of regional drainages benefiting from the more than generous snowfall. Estimates earlier this week concluded the amounts in the Henry’s Fork and Snake River drainages above Palisades Reservoir are around 120% of normal, and the Big Lost River’s is about 140% of normal. Other sinks drainages are at similar amounts. But not to be outdone, that of the Bear River’s is about 170%. And leading the pack, those of the Blackfoot, and Portneuf Rivers and Willow Creek are about 185% of normal. This abundance of snowfall in those four latter drainages could not be better news for the immediate future of endangered native cutthroat trout the major salmonid in each of these.
The effect of this abundance is that first ground water amounts will be restored to natural levels, then streams will be restored to the same, and still waters will move closer to natural volumes. Irrigation draw -downs will not have as negative an impact on hosted fisheries as in past years. In particular, many of our depleted smaller waters, not influenced by storage reservoirs, will “come back to life” with respect to providing better conditions for hosting salmonids and therefore being fished.
Spring time weather will determine the length and intensity of the upcoming run-off season, and can even impact the first months of fishing season. Even if a delayed fishing season occurs, the amount of water generated from the abundance of snow melt will benefit our salmonid populations in that it will begin a restoration to natural amounts. And the cooler waters will provide higher concentrations of dissolved oxygen which salmonids need to be active.
So anglers and our salmonids alike will benefit from the furious winter that is finally winding down. It may mean a delay in our best fishing conditions, but such is worth the wait when more active salmonids for a longer time are results of a winter that brought so many road closures, shoveling, and downright foul weather.
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL
Here are Dr. Rob Van Kirk’s Snow-Water Equivalent (SWE) report headlines for the Henry’s Fork drainage today, March 28th.
There is no end to cold, wet weather in sight. The latest 7-day quantitative forecast is now calling for widespread precipitation exceeding 0.75 inch over even the driest parts of the watershed, with up to 3 inches of water equivalent at the highest elevations. Below-average temperatures are expected to continue well into the month of April, with high confidence in that outlook.
At an outflow of 250 cfs, Island Park Reservoir is 86% full, compared with 82% full on average. The three reservoirs in the Henry’s Fork watershed are 88% full, compared with 86% full on average.
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL