2008 water outlook awaits spring resultsWritten by Christy Hemken
However, whenever people ask him for predictions of what the future holds in the relationship between Wyoming and water, Lawson responds he doesn’t have even a vague idea.
“Right now the temperature outlook for April, May and June is a statistical average, as well as the precipitation outlook for those same months,” he says, adding, “The ‘EC’ on those forecast maps stands for ‘I don’t have a clue,’ rather than ‘equal chances.’”
“Right now you’re hearing all kinds of good things about how things are improving, but it’s interesting that we can have something that’s less than average and have it be good news,” says Lawson of this year’s moisture levels. This year the Wind River is at 92 percent of normal, while last year it was at 72 percent.
Currently the North Platte River is at 111 percent, however, Lawson says to keep in mind that has dropped from its recent 117 percent. “The Lower North Platte, from Pathfinder down to Guernsey, was at 86 percent last year, and it’s at 93 this year,” he notes.
“If you’re looking at last year compared to this year, it’s good news. But I don’t think it’s great news, from my perspective,” he says. “I’d like to see those percentages a lot higher throughout the next six weeks.”
Lawson referenced a statement by the Billings Gazette that said Yellowtail, at 97 percent, was encouraging. “I find that ironic, but that shows what we’ve been going through, and continue to go through.”
He said the good in the state exists in the Shoshone Basin. “This dry period started in 2000, and the 30-year average at that time was over 700,000 acre-feet of inflow. Last year we had 427,000 acre-feet of inflow, and I’m calling this good.” The new levels represent 78 percent of the old average.
Lawson says Reclamation has had fairly good luck managing Buffalo Bill Reservoir. “The 15-year average has dropped from 460,000 acre-feet down to 435,000 acre-feet, but we’re fortunate in that we don’t have an over-demand on that water.”
Related to inflows, Lawson says outflow is dropping 10 percent annually on average. However, Reclamation has worked in a collaborative process with the Wyoming Game and Fish Department to establish a winter flow acceptable to all parties comprehensively, including fisheries and irrigation.
Not only is outflow important to downstream users, that water is also used to pay the bills. “Every one of these reservoirs is associated with a power plant system, and they pay the bills,” explains Lawson. “We’re generating about half of what we normally would, and because of the drought power customers are going out to buy power to meet their commitments at a cost of three to four times would they would normally pay.”
According to Lawson, the ugly part of the state is the North Platte system. “Seminoe Reservoir tells us if we’re going to survive or not. We had a record low flow in 2002 of 118,000 acre-feet, while the average was 799,000 acre-feet. We haven’t been able to get any recovery since then.”
The entire North Platte system of dams and reservoirs has historically contained 1,615,000 acre-feet on the 30-year average until 2000, when the system held 1,740,000 acre-feet. The year 2007 ended with 706,000 acre-feet in the entire system.
Although the North Platte Basin sits at 111 percent snowpack in early March, Lawson is hesitant to show optimism. “This time in 2006 we were at a higher percentage of normal, and we only got 546,000 acre-feet of inflow that year out of an average 703,000 acre-feet,” he says. “With that high snowpack percentage we were forecasting 850,000 acre-feet for 2006 and we fell on our face.”
The snows quit in April, temperatures warmed, causing an early melt-off, and additional moisture didn’t come. “In 2005 we were way below average this time of year, and that year we got 732,000 acre-feet of water. We thought we were going to be down, but then we got heavy, wet snows in the spring and that’s what gave the 732,000 acre-feet,” he says.
“We’re hoping we’ll get 700,000 acre-feet this year - based on the historic information - but we have a minimum plan of 450,000 acre-feet, which is not unrealistic,” he notes. “It depends on what will happen in next six weeks.”
The entire North Platte system holds 2.8 million acre-feet of water but ended at 706,000 acre-feet last year. “We could end up at 604,000 acre-feet next September under the minimum predictions,” says Lawson. “Seminoe Reservoir holds one million acre-feet and it’s only 18 percent full today. We could get that up to 265,000 acre-feet this coming September, or we could go as low as 194,000 acre-feet.”
“The nightmare for us is Pathfinder,” says Lawson. “If we get the minimum plan we could have Pathfinder down to 100,000 acre-feet this September. We ended last year at 171,000 acre-feet, while it holds one million acre-feet.”
Lawson says irrigators have a dilemma because they’ve been holding off until June to take water. “About one-third of their irrigation is hay, and if they don’t get a watering early on it affects the crop the whole year. If they decide to come on early, and we get a minimum inflow, we’ll have this reservoir at minimum.”
Lawson says the absolute minimum in Pathfinder is 30,000 acre-feet – a level after which water can no longer flow through the outlets.
“Seminoe hasn’t come into priority since 2000, so we’ve been living off that to serve the Casper Alcova Irrigation District. Until we get Pathfinder filled, Seminoe will never come into priority, while every year we’re drawing 100,000 acre-feet out of Seminoe,” says Lawson, adding another 100,000 acre-feet of water is lost to evaporation annually.
Regarding how many good years it would take to fill as the reservoirs again on the North Platte, Lawson says it depends what’s called a “good year.”
“We were very close to this same mess in 1993 – by September 1993 we had the system down to 700,000 acre-feet, just like we did last year. But, from 1997 through 1999 we got 1.3 million acre-feet into the system – more than double the average,” he says. “If we could get that series that occurred then, in two or three years we could fill it back up.”
He says one scenario not seen for quite some time are years like 1983 and 1984 where the system received 2.2 million and 2.3 million acre-feet of inflows in consecutive years. “The system only holds 2.8 million, so imagine how you would manage that. And it does change that quick. We could get quick recovery or this thing could extend for a long time.”