Billy Clapp Lake

"Spring Coulee is a fine scabland canyon, with castle-like buttes, lateral subsidary canyons, and cataracts notching its walls"

J Harlen Bretz (1932)

We can no longer walk the floor of Spring Coulee as Bretz once did. Today the coulee carved by the Ice Age Floods is used to move and store Columbia Basin Irrigation Project water. Many of the Ice Age Floods features Bretz marveled at above the coulee floor are still visible along the shoreline of Billy Clapp Lake.

Bruce Bjornstad and I enjoyed a nice hike from Summer Falls to Pinto Dam Saturday. We found several great flood features during the hike. This shot shows Summer Falls and the USBOR hydro facility at the north end of Billy Clapp Lake.

During the construction of the Columbia Basin Irrigation Project, the Bureau constructed Pinto Dam at the south end of Spring Coulee to create Billy Clapp Lake. Irrigation water is pumped from the Columbia River at Grand Coulee Dam into the Grand Coulee (Banks Lake). To move water from Banks Lake to Billy Clapp Lake the Bureau used a series of canals, siphons and tunnels that have the capacity to carry 19,300 cubic feet of water per second. This water then flows south to irrigate 671,000 acres all the way to Pasco.

Lake named for one of the first to visualize Grand Coulee Dam -

William "Billy" Clapp (1877-1965), a lawyer in the small town of Ephrata. Clapp became convinced that whatever nature had done with ice in prehistoric times modern man could do with concrete. (From HistoryLink.org)

Pinto Dam and Billy Clapp Lake - USBOR Image

Grand Coulee Project - An opportunity created by The Ice Age Floods

Grand Coulee Dam (USBOR site)

Columbia Basin Irrigation Project (USBOR site)

Request Free Irrigation Project Brochure

Click USBOR map above to get a better look at the project. The Bacon siphons and tunnels are shown as #1 - The bifurcation point where the main canal splits into the East Low and West canal is shown as #2. Arrow points to Billy Clapp Lake.



In many locations the Bureau took advantage of Ice Age Floods channels to move water. Between Dry Falls Dam and Billy Clapp Lake they were forced to create their own channel through the basalt. First a canal was dug to feed water into the 1,000ft. Bacon Siphon that crossed Don Paul Draw. On the other side of the draw the siphon discharged into the two-mile long Bacon Tunnel. Project water then flowed through a canal system to Summer Falls. Years later a second siphon and tunnel were constructed.

You should be able to expand any of the images by clicking. That tunnel work doens't look like much fun.



NOTE: Black and white images showing canal, siphon and tunnel construction are from the Rufus Woods Collection housed at the Central Washington University Archives.

Image shows the largest erratics we found on the trip.


Bruce standing on a Giant Current Ripple. I'm on the next ripple downstream. Great place to get a feel for the power of the floods!


We found an impressive pothole about halfway through the hike. I need to start measuring these things.

Pothole Gallery