The Columbia River is flowing smoothly nearly six months after the last vestige of the Mid-C Hourly Coordinating Agreement—which coordinated power generation among Chelan, Douglas and Grant county PUDs—expired.
The transition from a coordinated river to independent operations has had its hiccups. However, none so far have been significant.
Based on interviews with utility officials, Douglas County PUD appears to have benefitted the most from the breakup, while Chelan County PUD and Grant County PUD have reaped some ancillary benefits from going it alone, but it's unclear for them if life is better with or without the agreement.
The Mid-Cs and BPA continue to share information so each entity knows what to expect in the immediate future.
Grant and Chelan say they are open to reviving a coordinating agreement in the future, although ongoing market evolution could make that unlikely.
From the early 1970s until 2017, the seven hydroelectric dams from Priest Rapids to Grand Coulee on the Columbia River's main stem ran like an orchestra. Under the Mid-C Hourly Coordinating Agreement, two upstream federal dams—Chief Joseph and Grand Coulee—primed the five PUD dams downstream. Chelan, Grant and Douglas ran their dams—Wells, Rocky Reach, Rock Island, Wanapum and Priest Rapids—essentially as a single generator.
Incoming power requests were served by whichever dam could best handle it at the time, regardless of which PUD was contractually obligated to meet that load. Operations were centrally run by Grant PUD.
However, two developments put strain on the agreement—intermittent resources took up more and more of Mid-C wholesale power customers' portfolios, and Bonneville increasingly had to manage flows to meet endangered fish obligations (CU No. 1822 ).
The first development meant much more volatility in customers' power requests, which made coordinating operations progressively more difficult. In the past, customer demand had been consistent day to day. This meant, for example, that early morning releases from Grand Coulee and Chief Joseph powered Wells and Rocky Reach dams to meet the morning peaks of IOUs, and that the increased water flow reached the lower PUD dams in time to serve afternoon and evening peaks.
But more and more renewable energy resources and new wholesale markets meant loads that were once steady could now rapidly fluctuate as Mid-C wholesale power customers balanced intermittent generation or responded to market signals.
"It's hard to even do what we would do in the past," Rich Flanigan, Grant's senior manager of wholesale marketing supply, told Clearing Up. "We could look at the load and know exactly when we were going to generate. We could move the water from Wells all the way down to Priest Rapids in a day."
While the Mid-C's flexibility has enabled the Northwest's rapid expansion of renewable energy resources, it also has made coordination exceedingly difficult.
From time to time, Flanigan said, he is still asked why the river isn't run as a cascading system.
"It's difficult to take advantage of a cascading system when you're allowing a lot of flexibility and there's a lot of volatility in requests," he said. "It's difficult to actually optimize those five projects without putting in constraints to make sure that you can actually move water from the upper river to the lower river."
The second development—BPA managing flow for fish purposes—meant the PUDs had less say over how much water came downstream. With a lessened ability to maintain higher forebay elevations, Douglas PUD set out on its own when the coordinating agreement expired on June 30, 2017.
Given these significant changes, the PUDs and Bonneville had different priorities by 2017.
"When you look at hourly coordination, there are different things that people value: pondage, capacity, flexibility" and so on, Flanigan said.
Each of the Mid-Cs and BPA had different priorities, he said. "We could just never get to an agreement."
Coordination hobbled along with the remaining three until the end of 2018, when BPA exited. Chelan and Grant signed a bridge agreement, continuing coordination through Nov. 13, 2019. That gave Chelan enough time to update its control and dispatch systems, functions Grant formerly provided.
"We took a very old system and modernized it," said Gregg Carrington, Chelan PUD energy resources managing director.
Now, Chelan has much more fine-grained insight into its hydro operations, he said. "That's the good aspect" of ending coordination.
The PUD is focused on debugging its new systems, but down the road its goal is to operate independently "while recouping coordination's benefits through bilateral agreements," Carrington said.
Chelan hopes bilateral arrangements can resolve any mismatches.
Douglas spokeswoman Meaghan Vibbert said exiting the agreement has been good for Douglas PUD so far.
There has been a learning curve for going independent, and Douglas has developed and refined operating strategies better suited to the new conditions, she said.
"Independent operations have produced a higher average hourly forebay elevation," Vibbert said. "This allows the district and its participants to share in more energy and capacity given the same amount of water."
Also, "internal operating costs are lower than our former share of Mid-C costs," she said.
Breaking up has brought challenges, too.
"There have been hydraulic mismatches since Nov. 13," when the bridge agreement ended, Carrington said.
Those have been manageable, so far. But Carrington and Flanigan both said there are scenarios that could pose serious challenges for one or more of the Mid-Cs.
"Let's say Chelan customers want to run full out for eight hours, but Douglas cuts back on its load," Carrington said. "We'd end up draining our reservoir and could potentially run out of water."
It is an unlikely scenario, but not impossible. The 624 MW Rock Island Dam has a smaller reservoir than Wells, Rocky Reach, Rock Island, Wanapum and Priest Rapids.
Even during coordination, Chelan occasionally had to use market purchases to cover contractual obligations. "Perhaps it is more likely now," he said.
Grant PUD has faced occasional challenges meeting flow requirements around Priest Rapids Dam, the farthest downstream of the five dams, Flanigan said. "We saw some challenges [in 2018 and 2019] without having Wells," he said. "Now we don't have Rocky Reach or Rock Island, either."
If the river level drops too quickly, salmon can be stranded in side pools. Anti-stranding provisions are part of the Hanford Reach Fall Chinook Protection Program Agreement, which includes BPA, Chelan, Grant and Douglas as signatories.
"Everybody has a stake" in managing river flows as required by that agreement, Flanigan said.
It is difficult, though, making those obligations part of operating procedures, he added. "We're working through some of those operational things right now with Chelan, Douglas and Bonneville."
Already, officials of the Mid-C PUDs and BPA are meeting weekly to share information about planned outages, flow requirements and other things to ensure everyone has an accurate picture of what is happening on the river in the coming few days.
"It's not every dam for itself," Flanigan said, noting that it was an amicable parting.
"I equate it to a marriage that just kind of fell apart and everybody went their separate ways," he said. "Who knows, in a couple years, maybe we'll start missing each other and get back together."