Citing the postponement of irrigation due to recent precipitation, Reclamation will increase releases to the river by 100cfs this afternoon at 4pm. This will bring the total river releases to 2,600cfs.
This time of year is crucial to a robust rainbow spawn. Please reports sightings of rainbows on redds to help biologists better evaluate the impact of rising releases on the spawners.
The April through July inflow forecast indicates Reclamation needs to increase releases to make storage available. At 4pm on Thursday, releases will increase 250cfs, from 2,250cfs to 2,500cfs.
2,500cfs is the minimum flows required to sustain a healthy fishery.
Citing a turn for the better with regards to precipitation and snowpack, Reclamation will increase river releases 250cfs. Look for the increase to occur at 4pm on Thursday.
This small increase will bring releases up to 2,250cfs, up from 2,000cfs. Minimum releases to wet all important side channel habitat is 2,500cfs.
The current lake elevation is just shy of 3,620ft. which is nearly 12 feet higher than historical averages.
As anticipated, river releases to the Bighorn River will drop from 2,500cfs to 2,50cfs at 8am on Monday morning.
Wyo.-The Bureau of Reclamation has scheduled a flushing flow in the Big Horn River downstream of Boysen Dam, according to Wyoming Area Manager, Carlie Ronca. This operation is at the request of, and in coordination with, the Wyoming Game and Fish Department.
“The purpose of the flushing flow is to improve trout reproduction by flushing fine sediments from spawning gravels in the river,” said Ronca. The flushing flow also improves insect production in the stream by opening up interstitial spaces between gravels and cobbles. The flushing flow is generally welcomed by anglers because it provides easier wading conditions. Following the flushing flow there is a reduction in floating algae.
Flows in the river below Boysen Dam will fluctuate from 600 cfs to 5000 cfs during the flushing flow. On Mar. 21 at 2:00 a.m., the release of water from Boysen Dam will be increased to 3000 cfs and further increased to 5000 cfs at approximately 7:00 a.m. for 10 hours before being reduced gradually back to 600 cfs by approximately 10:00 a.m. on Mar. 22, 2016.
The public is urged to use extreme caution during this period of rapid fluctuation of flows below Boysen Dam.
During the bi-weekly stakeholders call with Reclamation today, the Bureau indicated conditions have warranted a slight reduction in releases. In the next day or so, expect releases to drop from 2,500cfs to 2,250cfs.
While we always hate to see the river drop below 2,500cfs, we believe Reclamation is acting appropriately given the current conditions and inflow forecasts. We all know that had these same conditions come about 6 or 8 years ago, we’d have already seen releases well below 2,500cfs. Hats off to Reclamation for balancing the resources.
With high water and low water come challenges. Please let us know of any hazards you find along the river, including boat launching and recovery, and we’ll get ’em posted here.
Better, but we’ve got a ways to go yet.
Folks, if you have a minute, I’d like you to take a look at something that illustrates some of the problems I’ve been trying to relate since Reclamation implemented the new operating criteria.
This first graph shows us the average lake elevations and river releases for the last 7 years. A few things stand out. First, on average, Reclamation starts each water year on Oct 1 with pretty close to a full lake. That’s seems nice. Second, on average, Reclamation takes the lake well into the flood pool. That’s not so nice if you happen to recreate on the north end of the lake. Thirdly, on average, the lake elevation only drops to 3,618ft. Wow! That’s really sweet if you boat at the south end of the lake and most certainly a coincidence that the minimum boat launch elevation was 3,617ft at that time! Fourth, the river is at or below minimums for half the year, hanging on for dear life for four weeks while the flows climb and ruin the rainbow spawn and flush out the brown fry, then endure high water cancellations for a month, followed by waiting out nearly two months of flows dropping back to minimums as the algae starts to take hold. Makes a person be glad winter has finally come.
Next we have a graph of the same information, but this time the the date range is from 1991 to 1998. At a glance, they two graphs look a lot alike. However, look at the Y axes on the left and right on both graphs. Let’s look first at the lake elevation on the left sides. On the graph below, you’ll see Reclamation used to start the water year about three feet lower that they do now. That sounds scary. But wait! Here’s where things get interesting. Follow the lake elevation down and you’ll see, on average, it bottoms out at 3,609ft. That’s a whole 9 feet lower than how they’re managing the lake now. That has to be bad, right? Hmmm… looking at the river releases, they’re above minimums and even mostly well above minimums. That’s definitely good! Hold on! The peak release is also lower. Clients don’t cancel when flows are under 6,000cfs, so that’s good, too! Come to think of it, the banks aren’t caving in either, so that’s another plus. But if the river is getting all that love, it must mean the other stakeholders are getting screwed, right? No, the lake elevation, on average, was nearly 3,620ft on Memorial Day and there was plenty of water during the summer, so the south end is happy. Surely the hydropower folks are screwed, right? Nope. More water in the river means more water went through the turbines. Stakeholders are happy and Reclamation has met its obligation to provide flood control, irrigation, hydropower, recreation and fisheries. Come to think of it, no one was bitching from either end of the lake back then. Little wonder.
We’ve now had enough years to evaluate the success or failure of the new operating criteria. One could argue that the criteria hasn’t been fully tested because its never been completely followed. Just this spring the March target specified in the criteria was missed by 9 feet. Whether that miss was intentional or simply pilot error, the new operating criteria ain’t cutting the mustard. Since the criteria, we’ve seen river flows in excess of 8,000cfs six times in eight years. You have to go back 26 years prior to that before you’ll find another six years of flows over 8,000cfs.
Please join me in asking Reclamation to return to sensible and balanced water management and end this cycle of overly conservative water management.