From email from Reclamation (Kara Lamb):
It has been a busy summer on the Colorado-Big Thompson Project. We have had a couple projects over the past two months that influenced the flow of project water.
In mid-to-late summer, we began our third operational experiment as part of the Three Lakes Water Clarity program we have been working on collaboratively with our project partners on the West Slope Collection System. This reduced the amount of water coming across the Divide to approximately 250 cfs. At the same time, the August heat arrived and some demands came up along the Big Thompson River. As a result, water levels at Lake Estes trended down from an average daily water elevation of 7473 to 7471–two to four feet below completely full.
At Carter Lake, we began running Unit #3, our reversible unit normally used to pump water up to Carter Lake, to generate hydro-electric power and deliver water back down to the Big Thompson River. Consequently, after staying fairly full all summer, the water level at Carter Lake declined quickly over the course of August from approximately 5751 (eight feet below full) to about 5727, a fairly typical elevation for this time of year.
Pinewood Reservoir also saw a water level decrease in August, dropping quickly at the beginning of the month from 6579 (one foot below full) to about 6569. Today, Pinewood is back up to an elevation of 6572.
In more typical years, Carter would still see the elevation decline, but over the course of the summer months. Pinewood would fluctuate more on a daily basis.
Only Horsetooth has maintained a slow draw over the course of the summer. We are still above an elevation of 5400 going into Labor Day weekend.
The water clarity experiment ends the day after Labor Day. We will begin increasing flows through the Adams Tunnel that same day and anticipate we will be running a full project by the next weekend. We do not anticipate turning the pump up to Carter Lake back on for some time.
Residents around and visitors to Pinewood Reservoir will start seeing some construction traffic up to Pinewood Reservoir and on up towards the Pole Hill Power Plant following the holiday weekend. I will have more information on that project also after Labor Day.
More Colorado-Big Thompson project coverage here.