From The Pagosa Sun (Chris Mannara):
River flows projected to be third lowest on recor
As of July 25, the San Juan River is currently flowing at 73.2 cubic feet per second (cfs).
According to Colorado Basin River Forecast Center (CBRFC) Senior Hydrologist Greg Smith, his- torically, the San Juan River is usu- ally flowing around 150 or 160 cfs.
“That’s kind of the mid-range, that’s kind of the median value, historically. So, I mean, we’re less than half that,” Smith said.
The San Juan River is above flows that were recorded back during the drought of 2002, Smith added later.
During the 2002 drought, cfs levels were around 45-50, Smith explained.
“Still, it’s kind of in the bottom few years, you know, the current flows,” Smith said.
These low river flows stem from the “dismal” winter season that Archuleta County had with poor snowpack conditions, Smith added further.
“And then, of course, we entered the spring somewhat dry as well, which didn’t benefit things. And you still have draws on the river from ir- rigation, especially as you go further downstream,” Smith explained.
This year, Smith described, was the “perfect storm” for low river flows.
Additionally, the seasonal spring runoff volume is currently at 71,000 acre feet (AF) for the San Juan River in Pagosa Springs, Smith added.
“It’s probably not going to be a lot more than that when it’s all to- taled up, the April through July for this year,” Smith said. “And that’s going to be, probably, it looks like to me, the third lowest on record.”
The lowest recorded spring run- off volume was recorded in 2002 with 23,000 AF flows, Smith noted.
The CBRFC has records for spring runoff volumes for the San Juan River dating back to 1936, Smith added later.
“Kind of the only hope we have at this point is if we can just get enough active monsoon weather to at least give us some additional runoff from rain flow,” Smith com- mented.
“The bulk of what you get comes from snow melt. You can get some pretty good stream flows due to the monsoon, due to thunderstorms, but they’re short-lived,” Smith said later.
When the public sees such low cfs numbers for the San Juan River, Smith explained that educating the public depends on what its uses are for the river.
“I mean there’s concern for everybody when you get real low flows, you know, from people get concerned about the fisheries and the amount for irrigation,” Smith explained.
A lot of the general concern for the public is if this current year is a low-flow year for the river, what will happen next year, Smith noted.
“Right now at least we have a benefit from how wet last year was,” Smith described. “You know, Navajo Reservoir managed, as you get further downstream, to have some pretty good storage carry over from last year.”
Some of that storage is “saving people” this year, Smith noted.
Another dry year could create some significant concerns among the public, Smith added later.
“There’s been enough water, at least below, for folks below the reservoir. As my understanding this year that they didn’t have re- ally serious shortages,” Smith said.
Low in-stream flows can affect recreational activities as well as irrigation, Smith explained.
However, because of last year’s wet season, Smith notes that there is some optimism to be felt.
“It is cause for concern when you get flows that low. But, you know, this year, again, I think we benefited from last year being so wet. So, it could have been so much worse this year, especially as you get further downstream below the reservoirs,” Smith explained.
Next year will be a year that the CBRFC watches closely, Smith stated.
“Because we could be in a tough situation next year if we had an- other year like this,” Smith said.
Unfortunately, low river flows are a problem that just can’t be solved physically, Smith later com- mented.
“You’re just kind of at the mercy of what happens. Below reservoirs you have a little more control of course in maintaining certain levels for fisheries or for irrigation needs as long as you have the wa- ter source,” Smith said. “But when you’re away from that, when you’re up in the higher elevation headwa- ters, you’re pretty much just at the mercy of mother nature.”
People are seeing flows that are certainly among the lower ones that have been on record for this type of year, Smith added later.
“If folks are saying ‘Wow, I haven’t really seen this,’ then, you know, they probably haven’t,” Smith explained.
“It’s amazingly low. Hopefully we’ll get some monsoon moisture here to push us through the rest of the summer.”