Rain on Snow Brings Much-Needed Flush to Florida River!

Thirteen years ago, in June 2002, the Missionary Ridge Fire in southwest Colorado burned for 39 days and consumed nearly 73,000 acres, including 56 homes. One firefighter lost his life. The skies were dark and thick with smoke, and in the aftermath, there was debris, mud, soot, and trees strewn in the river channel below Lemon Dam. Thanks to the heavy May precipitation this year, John Ey, Lemon Dam Superintendent, was able to make high releases from the reservoir and flush the Florida River channel. This provided a much-needed cleansing to the river, which had been unable to be accomplished in recent years due to prolonged drought conditions that have occurred since the 2002 fire. The extended high releases will provide numerous benefits to the river and ecosystem. Benefits include improved aquatic food base and spawning habitat, riverside vegetation, and wildlife habitat.

In what Eric Kuhn, with the Colorado River Water Conservation District, called ‘miracle May,’ statewide precipitation was more than twice the average. The moisture was especially welcome in the southwest Colorado’s Dolores/San Juan River Basin which received well over three times the normal amount of May precipitation, 349 percent of average (see graph, left). These amounts were the highest on record for most SNOTEL sites across the San Juan Mountains in the month of May. The winter snowpack never reached median values in the San Juans, but the spring moisture will help sustain river flows.

Reservoir storage across the state remains very similar to last month statewide, at 107 percent of average, with most basins showing only modest changes from last month. The southwest basin reservoirs were one of the main exceptions to this, showing a very large increase over the previous month. “The unexpected May weather has certainly improved reservoir conditions throughout the Basin," said Susan Behery, Hydraulic Engineer with the U.S. Bureau of Reclamation, Western Area Office. Area reservoir levels and some reservoir superintendent  comments include:

Jackson Gulch Reservoir (55% full in April to 90% full in May). As Gary Kennedy stated: “It has been quite a water slide this spring. From little snow and low run off with Jackson Gulch reservoir on May 12th at 60% full and an irrigation allotment set at 53%. Today June 10th Jackson is full with a 100% irrigation allotment and an additional 200 acre feet up for lease. Tonight the West Mancos river is running 230+ cfs (see West Mancos River pic, right) and headed to Lake Powell. In the water world you must never give up!”
Lemon Reservoir (70% full in April to 86% full in May). John Ey conveyed: The rains resulted in the need to make releases for flood control, and at the same time fill the reservoir. With this unprecedented (in this basin) rain on snowmelt event there were no other comparable years to gauge the possible peak inflows. John likens it to the annual spring poker game with Mother Nature, and she always holds the wildcards, and this year she is playing them. At this point in time the reservoir is at full capacity, the water users have a 100% water supply and the flush of the river channel was within the safe channel capacity.
McPhee Reservoir (55% full in April to 69% full in May). Mike Preston indicated: "The rains made a really big difference in irrigation supply. Demand on irrigation started off slow because it was supplemented by Mother Nature, and that works to stretch supplies further into the season."
Vallecito Reservoir (86% full in April to 96% full in May). Brian Shuffield stated: “During the time when we were filling the lake, we saw abnormally high moisture in May/June storms combined with the effects from rain on snow melting which added to existing inflows. Due to these conditions, we experienced extremely high inflows into the Reservoir. At one point, inflows were approaching almost 4,000 cfs for a period and we were sending down 3,000 cfs in the river which is above and beyond recommended releases for the river channel. It will be interesting to see what the monsoons are going to do knowing that we have already seen abnormally wet weather.”

Melissa Schneider, with the Colorado Division of Water Resources, shared that both Shuffield and CDWR’s Dave Hoffman, water commissioner on the Pine River, “where up all night for two days in a row watching the elevation on the reservoir.” As Ey stated, “it was a very challenging time.” Ultimately Miracle May proved the incredible amount of skill that we are fortunate to have in our southwest Colorado reservoir operators!