Tour Deschutes (River) Geohydrology Field Trip

  • 22 Aug 2023
  • 9:30 AM - 4:00 PM
  • Newport Ave Bridge
  • 0


Registration is closed


Hal Werhow, COCC Geology Professor, led us on all day field trip studying Geohydrology of the Deschutes River. 17 were in attendance (19 including Derek Loeb the coordinator and Hal.) We met at the Newport Ave. bridge where Hal began by telling us The Deschutes is famously known as a “Peculiar River”. The Deschutes is fed by underground springs rather than creeks. It is a steady river that has no flood plain, hence many have homes right on the river bank. The Newport Bridge, built in 1910, is a discreet looking dam, forming Mirror Pond. It provides electricity to 200 homes currently.

Our next stop was the Central Oregon Irrigation Diversion which carries water for agricultural use in Central Oregon. Hal gave a brief history of how water rights were allocated within this area. And an explanation of how reservoirs were built higher up the river for water storage so water can be distributed through canal systems for use over the growing season.

Next we visited MacGregors’ viewpoint in La Pine State Park. This section of the river meanders on a big curve with a significant exposure of an eroding river bank. This erosion and sediment dropping in the river is due to the fluctuation in river flows from the irrigation systems in place.

From there we went to Wickiup reservoir. We stood on the dam and looked down at the Hydro building . At this late summer day, the reservoir is only 25% full and will not last longer than another month, approximately, which is one month short of the water needs of farmers in Jefferson County. There are plans in place for conservation of the water from this river by piping the canals and other water saving measures. This is critical to meet the ongoing needs of this area.

Lastly, we stopped at Soda Creek where we learned how several creeks drain into the ground and the water moves through volcanic rock and finds the way into the Deschutes. The head waters are at Little Lava Lake, but its arguable that these creeks actually are the beginning of the river. Not only is this river peculiar it is very important and special to our way of life.


Wikipedia, Spencer Dahl

Tour Deschutes (River) Geohydrology Field Trip

Led by Hal Werhow

Tuesday, August 22

9:30 AM - 4 PM

Please join Hal Wershow for a field trip focused on the geohydrology of the Deschutes River.

Join us as we explore "our peculiar river" on Tuesday August 22nd, from 9:30 am to 4pm.  Geologists such as I.C. Russell were amazed by the Deschutes River in the early 20th century, because it behaved so differently from the "flashy" rivers that are more common.  Rather than seasonally flooding and drying, the Deschutes ran consistently year-round.  As we have since learned, this is because the Upper Deschutes is primarily fed by groundwater, as opposed to surface water.  However, our peculiar river has changed dramatically since we began managing flows on the Upper Deschutes in the quest for irrigation water.  This has dramatically altered both the river's flow regime, as well as its capacity to transport sediment.   In this field trip, we will examine the consequences of managed flow as well as investigating the origins of the Deschutes in the High Cascades.

We will meet at 9:30 am at the Bend Hydro Dam,  There will be six more stops and nearly 3 hours of driving. Ride sharing will be greatly appreciated, especially as parking is limited and reducing our carbon emissions is always cool!  Per COGS policy ride sharing is completely voluntary. The second stop at the Mt. Bachelor Park & Ride off of Columbia Ave. is specifically for organizing ride sharing and is a safe and convenient spot for day time parking.

Please bring both a Deschutes National Forest / Federal Lands parking pass as well as an Oregon State Park parking pass if you have one.

Driving Directions via Google Maps:

Stop 1 - The Bend Hydro Dam (Newport Bridge) - meet at 9:30am. Paid parking is available at the city lot just east of the bridge on the north side of Newport Ave.

Stop 2 : Mt. Bachelor Park & Ride on Columbia Ave.

Stop 3 - River Canyon Park. Short hike to COID diversion gate.

Stop 4 - Don McGregor Memorial Viewpoint at La Pine State Park.

Stop 5 - Wickiup ReservoirStop 6 - Little Lava Lake.

Stop 6- Soda Creek at Cascades Lakes Highway (opposite Soda Creek Campground) - wrap up around 3pm.   Return to Mt. Bachelor Park & Ride at ~ 4 pm.

Trip is limited to 18 participants.  Please contact Derek Loeb, with any questions.

Registration must be done via the registration button on the trip listing on the COGS website.  Successful registration will be confirmed on the webpage by a light green box indicating registration was successful and by a confirmation email.  If you don't get this email you should try the registration process again.  If the trip is full, please join the wait list.


Central Oregon Geoscience Society

P.O. Box 2154,  Bend, Oregon 97709

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