Why Wanapum Reservoir Drawdown Matters to Chelan County PUD By Steve Wright General Manger Chelan County PUD steve.wright@chelanpud.org
hen word first arrived W at Chelan County PUD on Feb. 27 that there
was a crack in Grant County PUD’s Wanapum Dam just downstream from Rock Island Dam, I have to admit to feeling concern for our friends at Grant PUD. It was shocking that a crack could form.
Yet as the Wanapum reservoir kept receding in the days that followed the initial discovery of the crack, and Grant PUD’s attempts to stabilize the dam, it became very clear that there was potential threat to our own operations. Let me take a moment and tell you why and how the lowering of a downstream reservoir impacts us in Chelan County and what we have done to lessen the financial impact to our customer-owners and what we have done to improve the situation for irrigators, river recreationists and for the fish.
How Can Lowering the Wanapum Reservoir Affect Rock Island Dam? The most frequently asked question I get is why would lowering the river downstream of Rock Island make any difference, since Wanapum was built more than twenty years after Rock Island? The simple answer is today’s Rock Island Dam is very different than the Rock Island Dam before Wanapum was completed in 1963. For example, some of you may remember that the Rock Island reservoir was raised more than six feet in 1978 to add another powerhouse. Also many of the turbines and generators have been built or redesigned and replaced since Wanapum became operational. All of the engineering behind these changes was based on an expected Wanapum reservoir level that dropped dramatically in late February. The second most frequently asked question is, “Why does the level of the reservoir downstream make any difference at all to the operation of the upstream
P.U.D. CHELAN COUNTY
Rocky Reach Dam has had minimal impacts from the Wanapum Dam response efforts
We are working toward an early August completion, if all of the necessary permits are received. We are committed to keeping the reservoir accessible to boaters and fishers and we will put forward our best effort to make it happen.
S
ALCOA
Right Bank Fish Ladder Right Bank
e unexpectedly find W ourselves in uncharted waters. I feel fortunate to be
surrounded by people here at the PUD who recognize that After extensive engineering studies Rock Island Dam today is producing 90 percent of normal this is an emergency situation that requires extraordinary output Fish effort. Our colleagues in the reservoir?” That is, why did PUD. They have identified studies have put us in a federal, state and tribal agenChelan County PUD have the root cause of the crack position to produce roughly We have a huge investment cies who have a stake in how to lower the Rock Island and are working mightily 90 percent of the normal Rock in fish protection that is the river is managed also recreservoir when the Wanapum to find solutions that will Island output, minimizing threatened by the drawdown. ognize the significance of the reservoir was lowered? The restore the dam pier and will financial consequences. Juvenile and adult fish Wanapum Dam event and reason is that there is a direct allow them to safely raise the passage will work normally at have unfailingly worked with relationship between the Wanapum reservoir. Based on Agriculture Rocky Reach Dam. At Rock us in a collaborative and expeupriver and the downriver our regular communications Island Dam we anticipate ditious manner. Grant PUD While we are not an irrigation juvenile passage should also water levels when it comes to with them and information generously has shared time agency, we definitely incredible river forces on a they have released, we be as effective as during more and information in a period understand the importance dam. are operating under the normal conditions. of great stress for their utility. premise that the downstream of irrigated fruit trees to our Chelan PUD employees have Our generating equipment community. We held a public In order to address adult fish situation will remain as it is risen to the occasion, put in is designed for a specific forum on March 13 with migration upstream, the adult long hours with unwavering today at least until the last water elevation difference irrigators from Chelan and fish ladders will work as long dedication to provide value quarter of 2014 between the upstream side Douglas counties who draw as flows are high. However, to our customer-owners. It’s and the downstream side of After learning that there water from the Rock Island in the event of low river flow a time of great stress but also the dam. If the downstream wouldn’t be a quick “fix” for reservoir. Our partner in this conditions, the ladders may great reward when I see what reservoir is lowered beyond the Wanapum situation, effort was the Washington be inaccessible. We entered is being accomplished. design standards, the water Chelan PUD engineers Horticulture Association and into emergency contracts to pressure on the upstream side quickly developed a series representatives from state extend three of the ladders And, not lost in all of our of the dam increases. The of accelerated engineering and federal agencies were on so they will work under all efforts to respond to an risk is potential catastrophic studies that were tested hand to answer questions foreseeable flow levels. Teams immediate crisis situation damage to the hydroby third parties to give us for irrigators on the ground is the fact that no impact on generating equipment confidence that we could and what they and dive At Rock Island customer rates is expected risking human health and adjust the elevation of the would need Dam we anticipate teams in the due to the measures taken. safety and potentially costing Rock Island reservoir up to do if their juvenile fish passage water worked Our customer-owners millions of dollars to repair. approximately two feet to an irrigation should also be as night and have the benefit of years of elevation of 609 feet above intakes needed effective as during day to install thoughtful planning with The situation at Wanapum sea level on the upstream to be permitted the ladder more normal carefully crafted financial Dam put the Rock Island side of Rock Island Dam. for an extension extensions in conditions. policies and power purchase generating equipment at an With a minimum river flow due to the very difficult, contracts providing a meaoperating level that would be upstream of 45,000 cubic response to the turbulent sure of financial protection. outside the limits of previous feet per second (cfs), it meant Wanapum Dam situation. water conditions. They You can have confidence that testing. When we found that we could resume power completed the extensions not only is your investment in ourselves very suddenly in On March 22-23 we ran a test on the two ladders on the generation cautiously. The the PUD being protected, we an untested state we chose studies gave us confidence we by lowering the Rock Island Chelan county side of Rock also are working hard to save to respond cautiously and reservoir to approximately could operate Rocky Reach Island Dam in mid-April you money. conservatively to protect the 608 feet. We did that because and the third extension on within the normal elevation long term viability of the we believed that would likely the Douglas county side of range. We commit to keeping you assets that are so incredibly be the lowest the reservoir the dam will be completed in informed as conditions valuable to Chelan County We were able to gain would operate during June. The ladder extensions change. I hope you will tell and to ensure public and agreement from the the summer. We wanted are being modified to support me if there are ways to do an employee safety. As stewards Bonneville Power irrigators to be prepared for passage of lamprey. The good even better job of letting you of assets owned by the Administration and the the potential impact on their news is that we are seeing know the information you people of the county, it is our Bureau of Reclamation to pumps. normal fish passage so far. want. responsibility to act prudently. ensure that Chelan PUD We continue to provide would have 45,000 cfs river irrigators real-time Major Considerations – flow through October 15 of information on our website Agriculture, Recreation this year. This should allow (www.chelanpud.org us to maintain a sufficient and Fish Wanapum Dam Response) headwater at Rock Island ince Feb. 27, we have been Dam to keep the level at 609’. and a hotline number (509661-8000) so they can make Since then, aggressive efforts in regular contact with decisions about what they to complete engineering our colleagues from Grant need to do to protect their investment.
Rock Island Fish Ladder Extension
POWERHOUSE 2
Good News Through the Challenges We Face
River Flow
Center Fish Ladder
Location #2 Complete 4/18 Location #1 Complete 4/15
Left Bank Fish Ladder POWERHOUSE 1
Location #3 Complete 6/30
Because of collaboration, installation was completed in six weeks rather than the expected twoyears it would typically take
Recreation Perhaps our biggest unanswered question is how river levels this summer will affect the three public boat ramps on the Rock Island reservoir. It is likely that they Above: Outreach with irrigators is helping to reduce impacts will be inoperable below the 609’ level. Right now, all three Below: Intense effort underway to keep boat ramps accessible boat ramps are usable. This when river flows recede is due in large part to snow melt and spring runoff. We don’t know how long we will be able to enjoy these higher river flows. Our backup plan is seek permits to extend one of the three public boat ramps, most likely the Kirby Billingsley boat ramp located on the Douglas County side of the Rock Island reservoir.