The city of Aspen and Front Range water interests have reached a compromise 20 years in the making that allows more water to be sent east when the spring runoff is plentiful, in exchange for bolstering flows when the Roaring Fork River is running low in the fall. The deal is between the Twin Lakes Reservoir and Canal Co., which operates transbasin diversion tunnels underneath Independence Pass, and the city of Aspen and the Colorado River District, which works to protect water rights on the Western Slope.
The deal, which has its roots in a 1994 water court application from Twin Lakes that sought to increase diversions during the runoff in high-snowpack years. It will leave 40 acre-feet of water in Grizzly Reservoir when Twin Lakes exercises its rights under the 1994 proposal. That water will be stored in the 500-acre-foot reservoir and released into the Roaring Fork for about three weeks in late summer, when seasonal flows are at their lowest. The water must be called for and released in the same year it was stored.
Grizzly Reservoir, located about 8 miles up Lincoln Creek Road near the Continental Divide, is a component of the transbasin-diversion system. A tunnel underneath the reservoir channels water underneath the mountain to the south fork of Lake Creek in the Arkansas River basin, on the other side of the pass.
Additionally, under the deal, the River District will have the right to store 200 acre-feet of water in Grizzly Reservoir and can call for up to 150 acre feet of that water in a year. Importantly, that 200 acre-feet can be stored long-term in the reservoir until it is called for by the River District, which manages water rights across the Western Slope.
Another 600 acre-feet will be provided to the River District for seasonal storage in Twin Lakes Reservoir, also on the east side of Independence Pass. The district will then trade and exchange that water with various entities, which could lead to more water staying on the Western Slope that would otherwise be diverted through other transbasin tunnels.
Twin Lakes diverts an average of 46,000 acre-feet a year from the headwaters of the Roaring Fork and sends it to Colorado Springs and other Front Range cities. The city of Colorado Springs owns 55 percent of the shares in the Twin Lakes Reservoir and Canal Co., entities in Pueblo own 23 percent, entities in Pueblo West own 12 percent, and Aurora owns 5 percent.
Aspen and the River District intend to cooperatively use the stored water in Grizzly Reservoir to boost late-summer flows in the Roaring Fork as it winds through Aspen proper.
Water already flowing
The stretch of the Roaring Fork River below the Salvation Ditch on Stillwater Drive typically runs below environmentally sound flows each year for about eight weeks, according to city officials. And given that this spring saw a high run-off, the three parties to the agreement managed some water this year as if the deal was already signed.
“At the close of the current water year (which ended the last day of September), Twin Lakes started making releases of some of the water stored for the River District, followed by release of the 40 acre-feet, as directed by Aspen and the River District,” Phil Overeynder, a special projects engineer for the city, wrote in an Oct. 3 memo to city council. “These releases had the effect of increasing flows in the Roaring Fork through the Aspen reach by approximately 20 percent and will last for approximately a three-week period at the end of the lowest flow conditions of the year.”
Overeynder added that “both Aspen and the River District believe that this agreement, while not perfect, is of real and meaningful benefit to the Roaring Fork.”
Aspen City Council approved the agreement on its consent calendar during a regular council meeting on Monday. The agreement is on the River District’s Tuesday meeting agenda, and Twin Lakes approved it last month.
The deal still needs to be accepted by Pitkin County and the Salvation Ditch Co. in order to satisfy all of the details of the water court’s 2001 approval of the 1994 water rights application.
Junior and senior rights
In addition to its junior 1994 water right, Twin Lakes also holds a senior 1936 water right that allows it to divert up to 68,000 acre-feet in a single year and up to 570,000 acre-feet in a 10-year period.
Originally, the water diverted by Twin Lakes was used to grow sugar beets to make sugar, but it is now primarily used to meet the needs of people living on the Front Range.
The 1936 water right still has some lingering restrictions in high-water years, according to Kevin Lusk, an engineer with Colorado Springs Utilities who serves as the president of the board of the private Twin Lakes Reservoir and Canal Co. Under its 1936 right, when there is plenty of water in the Arkansas River and the Twin Lakes Reservoir is full, Twin Lakes is not allowed to divert water, even though it is physically there to divert, Lusk explained. So in 1994 it filed in water court for a new water right without the same restrictions so it could divert more water to the east. It was dubbed the “Twin Junior,” water right.
The city of Aspen and the River District objected in court to the “Twin Junior” and the agreement approved Monday is a long-delayed outcome of the case.
Aspen claimed that if Twin Lakes diverted more water in big-water years, the Roaring Fork wouldn’t enjoy the benefits of the high water, including flooding the Stillwater section and replenishing groundwater supplies. That process, the city argued, helps the river in dry times.
“We don’t necessarily agree with the theory behind it,” Lusk said of the city’s claim, but added that Twin Lakes agreed to the deal as part of settlement negotiations.
And since 2014 turned out to be a high-water year, Twin Lakes exercised its right to divert water under its 1994 Twin Junior right, and worked cooperatively with Aspen and the River District to release 40-acre feet of “mitigation water” as described in the pending deal.
The new agreement between the city, Twin Lakes and the River District is in addition to another working arrangement between Twin Lakes and Aspen related to the Fryingpan-Arkansas diversion project, which diverts water from the headwaters of the Fryingpan River.
That agreement provides 3,000 acre-feet of water each year to be released by Twin Lakes into the main stem of the Roaring Fork beneath a dam near Lost Man Campground, normally at a rate of 3 to 4 cubic feet per second.