Three Rivers Ranch’s Newsfeed

Thank you for visiting our newsfeed.  You’ll find the latest news on the Henry’s Fork of the Snake River, fishing news from around Idaho, and other news from Three Rivers Ranch.

 

Record Cold Slows Runoff, Buys Another Week of Good Flow Later in Summer

A three-day winter storm in the middle of the week set record cold temperatures for the date and greatly slowed snowmelt, saving that snow to melt later in the spring and summer. Elevations above 6,500 feet gained up to inch of new snow-water-equivalent this week, including the White Elephant site on the side of Mt. Sawtelle. As a result, current snowpack at the subwatershed scale is currently between 122% and 147% of median for the date. Although streamflow at most locations is below average this morning, warm temperatures forecast for the next 10 days will resume melt, leading to season-peak streamflows into Henry's Lake and in Fall River and Teton River around June 1. Henry's Lake and Island Park Reservoir will both fill around that time. Current Snowpack Conditions Cold temperatures and wet weather over the past week have greatly reduced snowmelt rates and even added new snow at most sites. As a result, snow-water-equivalent (SWE) as a percent of median for the date has increased rapidly, as can be seen in the graph below. At the subwatershed scale, SWE on the ground this morning ranges from 122% of median in the upper Henry's Fork to 147% in Fall River,

Above-average Runoff Benefiting Stream Habitat Across the Watershed

A well-above-average May snowpack has begun melting over the past week, resulting in above-average streamflow throught the watershed. Minimal amounts of water are being stored in the watershed's reservoirs, and irrigation diversion is only around 20% of total water supply. As a result, streamflows are very near their natural values--essentially the same flow the rivers would have in absence of reservoirs and diversions. These high, natural flows--occurring within the range of long-term average timing--are currently benefitting physical and ecological processes in stream channels and riparian areas throughout the watershed, mobilizing and removing fine sediment from the stream bottom, creating new habitat, and ensuring reproduction of cottonwood trees. After four years of drought, the sight of snowmelt filling rivers and floodplains is a welcome change. Snowpack Update Graph above shows percent-of-median snow-water-equivalent (SWE) since November 1 in the three subwatersheds of the Henry's Fork watershed. Also shown is the percent-of-median SWE for the Henry's Fork and Teton Basins, as reported in the Natural Resources Conservation Service (NRCS) daily snow/precipitation report. Table below shows data for individual sites, as well as the subwatersheds and the NRCS Henry's Fork and Teton Basins index. Rapid melt over the past week has decreased SWE as

Henry’s Fork Caddis Hatch

Spring is here and so are the first hatches of 2017. About a week ago there were rumors of caddis hatching on the lower Henry’s Fork, and after two float trips last weekend, I am happy to confirm this was true. To prove that we aren’t just robotic scientists that make figures and crunch numbers all day and that every so often we are able to get out and enjoy time on the river that we advocate for, here are some photos and videos from the weekend.     Ben nymphing up this beauty of a sucker before the hatch got underway. Great job, Ben!   Hatch was heating up.   Mats of caddis in the eddies and along the banks.   Plump Brown caught slurping caddis.   Clouds of caddis when the wind died down.   I need longer arms to turn the 17 incher into a 20+ incher.   Also, found a couple of these guys at the Buffalo River fish ladder today (May 5th) ... If you want to learn more about our macroinvertebrate on the Henry's Fork, check out Rob Van Kirk's blog explaining and summarizing our macroinvertebrate research. 

Water Year 2017 Looking Better Every Day

With a very wet April now in the books, the 2017 water year is certain to be above average in terms of water supply in both the Henry's Fork watershed and in the upper Snake River basin as a whole. Highlights are: April precipitation in the Henry's Fork watershed was 162% of the 1982-2016 mean and 261% of last year's value. May 1 snow-water-equivalent in the HF watershed was 146% of the 1981-2010 median and 228% of last year's value. April 30 natural streamflow in the Snake River at Milner was 171% of the 1988-2014 mean and 130% last year's value. Total diversion on April 30 in the upper Snake River basin was 82% of the 1988-2014 and only 72% of last year's value. More supply + less demand = higher streamflows. Current Snow Conditions in the Henry's Fork Watershed Graph above shows percent-of-median snow-water-equivalent (SWE) since November 1 in the three subwatersheds of the Henry's Fork watershed. Also shown is the percent-of-median SWE for the Henry's Fork and Teton Basins, as reported in the Natural Resources Conservation Service (NRCS) daily snow/precipitation report. Table below shows data for individual sites, as well as the subwatersheds and the NRCS Henry's Fork

April Showers Greatly Improve Water Outlook

Four weeks ago, water-supply outlook for the upper Henry's Fork watershed was average at best because of an extended period of warm, dry weather in March that had already melted much of the low- and mid-elevation snowpack. However, April has turned out to be one of the wettest on record, greatly improving water supply and increasing the probability that relatively little Island Park Reservoir storage water will be needed to meet irrigation demand this summer. With three days left to go in the month, Island Park has received 4.5 inches of precipitation in April, compared with the 1981-2016 average of 2.3 inches and a maximum over that period of 4.2 inches in 1993. However, temperatures have remained above long-term averages throughout the month. Current Snowpack Conditions Graph above shows percent-of-median SWE since November 1 in the three subwatersheds of the Henry's Fork watershed. Also shown is the percent-of-median SWE for the Henry's Fork and Teton Basins, as reported in the Natural Resources Conservation Service (NRCS) daily snow/precipitation report. Table below shows data for individual sites, as well as the subwatersheds and the NRCS Henry's Fork and Teton Basins index. Extensive loss of snow at Island Park, Crab Creek and Pine

Buffalo River Fish Ladder: April 2017 Update

Henry’s Fork Rainbow Trout migrating to spawn in the Buffalo River have to pass through the fish ladder at the Buffalo River hydroelectric facility to access upstream spawning habitat. At the end of the fish ladder we, HFF, operate a fish trap from early February through the middle of June. Three times a week we check the Buffalo River fish trap and collect data on species, length, sex, and life histories via passive integrated transponders (PIT) tags if one is present. This data allows us to quantify run size, run timing, number of spawners, number of return spawners, and other valuable information needed to monitor and understand the Henry’s Fork Rainbow Trout population. Here is a quick summary of the 2017 Buffalo River fish ladder as we approach the historic median fish passage date of May 6.      Notable Numbers   325 fish captured (February 17 through April 24) Rainbow Trout 85 spawning sized fish (greater than 12 inches) 16 inches - median size 21.6 inches - largest fish 155 juvenile fish (less than 12 inches) 5.3 inches - median size Brook Trout ​84 captured 5.8 inches - median size 9.3 inches - largest fish Sculpin 1 captured Figure 1.

Summer 2017 Streamflow Predictions: Much Better than 2016

To provide streamflow information for all river stakeholders, we have constructed a computer simulation model of the Henry’s Fork watershed stream, reservoir, and irrigation system. Using early-April water-supply conditions and long-term temperature trends as inputs, we expect streamflow conditions to be generally better than average and much better than last year across the watershed. Focusing specifically on Island Park Reservoir and the river immediately downstream, we predict: Streamflow during the second half of June at Island Park Dam will be roughly equal to the river’s natural flow. With 90% probability, this natural streamflow will range between 400 and 750 cfs. Irrigation delivery from Island Park Reservoir will begin around July 1 and peak in mid-July. With 95% probability, releases from the reservoir during July will be lower than 1,400 cfs, and with over 95% probability will be much lower than 2016 releases between the middle of June and the first week of August. With 95% probability, Island Park Reservoir contents at the end of the September will remain above 58,000 ac-ft (43% full), very close to the long-term average. Because of lower outflows and higher reservoir contents, turbidity (how “dirty” the water appears) in the river immediately downstream of Island

Summer streamflow predicted to be higher than last year

Based on snowpack and baseflow conditions as of April 1, predicted natural streamflows for the upcoming April 1 - September 30 time period are: Henry's Lake: 95% of average Henry's Lake to Island Park Dam: 85% of average Henry's Fork upstream of Ashton: 89% of average Fall River: 115% of average Teton River at St. Anthony: 125% of average Full results are shown in the table below. In last week's blog, I discussed the importance of long-term April 1 snow-water-equivalent (SWE) data for predicting streamflows for the upcoming spring and summer. I also showed that the long-term mean (or arithmetic average) of SWE is greater than the current 1981-2010 median value to which current SWE values are compared. The primary observation to make was that although April 1 SWE at many sites in the upper Henry's Fork watershed was above the 1981-2010 median, it was actually below the long-term mean at most sites, leading to below-average predictions of spring/summer streamflow. The percentages shown above are relative to the 1972-2016 mean for the Henry's Fork and the 1981-2016 mean for Fall River and the Teton River. The table above provides predictions of April 1 through September 30 natural streamflow in the

Buffalo River Fish Ladder: March 2017 Update

Hi HFF Community, My name is Ben Ortman and I am the newest addition to the HFF team. I was hired with HFF and moved to Ashton in January as a Conservation Technician, to work primarily on the 2017 Henrys Fork Economic Value Study in collaboration with Idaho Department of Fish and Game. With about half of my time dedicated to the economic value study, I am left with a good chunk of time to put towards other research endeavors, such as Buffalo River fish ladder monitoring.  The following is a summary of the results from the first five weeks of monitoring the 2017 fish migration through the Buffalo River fish ladder. Quick Facts 219 trout have utilized the Buffalo River fish ladder this spring from February 17 to March 23 49 spawning sized Rainbow Trout (greater than 12 inches) have been trapped over this period Only two species have been recorded in 2017, Rainbow Trout and Brook Trout Of the two species 74% were Rainbows, and 26% were Brook Trout Background In the early 1990’s, it was recognized that the population of Rainbow Trout in the Henry’s Fork was being limited by lack of available spawning habitat below Island