With water storage becoming more critical than ever, Colorado’s Rio Grande Basin moves to capitalize on existing reservoirs
Bruce Bagwell saunters into the Conejos Water Conservancy District office, housed in an old bank on Manassa’s Main Street. Bagwell casually nods hello to Nathan Coombs, who is busy at work, and pulls up a chair; he’s here to visit.
“Right now, I’m working up the ambition to start a fire,” Bagwell says. It sounds like an expression, but isn’t. Bagwell is a ditch rider, hired by the Manassa Land and Irrigation Company to maintain its irrigation channel and check on the headgates that allow water to flow, or not flow, off the ditch and onto private land. During irrigation season he drives up and down the Manassa system nearly all day long. In late March, Bagwell clears debris that filled the ditch over the winter, sometimes by burning it, to prepare for water to start flowing come April.
Coombs and Bagwell talk and laugh like old friends but both get more than good company from the visit—it’s about the water. The Conejos Water Conservancy District manages Platoro Reservoir, which can store nearly 60,000 acre feet of water to irrigate 100,000 acres of land. Much of the water that flows in the Manassa and other ditches along the Conejos, or beyond those ditches to reach the Rio Grande and flow out of state, is delivered from the reservoir.
Coombs must release the right amount of water from Platoro Reservoir each day to meet the rights of downstream users. He and Bagwell have installed automatic headgates along the Manassa and will soon do the same elsewhere in the Conejos system. The new headgates help ensure each user is drawing precisely the right allocation of water. According to the Colorado Water Conservation Board, water in the Rio Grande Basin is over-allocated and has been since the 1890s, plus most water here is subject to the terms of the Rio Grande Compact— not a drop should go to waste. If one person draws too much, another suffers.
Chatting with ditch riders like Bagwell helps Coombs groundtruth, or compare, the remote readings he gets from those headgates against actual measurements from along the ditch. “If this place is all on the same page, it simplifies everybody’s life,” Coombs says. As with most reservoirs, “this place” begins at Platoro, but the reservoir manager’s job extends downstream. “You do the best you can do for all the water rights,” Coombs says.
Colorado’s Rio Grande Basin has 13 major reservoirs, totaling nearly 350,000 acre feet of water storage potential—a quarter of what’s available in the mainstem Colorado River Basin’s reservoirs and significantly less than most other basins in the state. Yet, the Rio Grande Basin is intent on capitalizing on that storage to the greatest degree possible, as evidenced by recent, large investments made in reservoir upgrades and repairs. The basin has applied for, and received, more state funding through the statewide Water Supply Reserve Account than any other region in Colorado, according to Greg Johnson of the Colorado Water Conservation Board’s Water Supply Planning section.
In the arid San Luis Valley, investment in a reservoir is an investment in the future. Impacted by persistent drought conditions and a runoff period coming three weeks earlier than it has historically, the importance of banking water for use throughout the year has never been more apparent.
Rethinking Limited Storage
The shortage of reservoir storage in the valley ties to the Rio Grande Compact, which allocates the river between Colorado, New Mexico, Texas and Mexico. The need for the compact arose when San Luis Valley water users built irrigation ditches and canals in the late 1800s—river flows declined and downstream users blamed Colorado. In 1896, the Secretary of the Interior embargoed additional reservoir development on federal lands along the Rio Grande in Colorado.
“We got shut out on any reservoir development from 1896 to 1907,” says Travis Smith, superintendent of the San Luis Valley Irrigation District and the Rio Grande’s representative on the Colorado Water Conservation Board. “1907 was a significant date. The federal embargo was lifted and you have this huge effort of reservoir development in the valley.”
Disputes continued and additional embargoes were placed on the Rio Grande until the compact was signed in 1938. Reservoirs installed after that date must now meet certain conditions—which are more difficult to meet during drought periods—before storing water.
Between replacing aging infrastructure and creatively meeting a multitude of needs through new operating schemes, opportunistic planning is helping the region take advantage of what limited storage it has.
“We have to do some innovative thinking to utilize the capacity of our reservoirs,” says Rod Reinhardt, former president of the Terrace Irrigation Company board and manager of Terrace Reservoir’s new spillway project. “We’re trying to stretch a drop of water as far as it will go. I think we need to come up with ways to think outside the box a little bit to make our water serve all the purposes that it needs to serve.”
Meeting Multiple Needs
Terrace Reservoir is on the Alamosa River, which doesn’t reach the Rio Grande at the surface and is not administered under the Rio Grande Compact. The reservoir was built in 1912 and is still used for irrigation; Reinhardt himself pulls water as a farmer. However, following the Summitville Mine disaster of the late 1980s—where heap leach gold mining polluted the Alamosa River above the reservoir— Terrace has also been instrumental as a water quality buffer. That buffering and ability to store water have been connecting environmentalists and irrigators in recent years.
“It’s a long story,” Reinhardt begins. The story starts in 1976, when a rogue storm system came north from the Gulf of Mexico and caused flooding in northern Colorado. A dam safety crackdown followed—dams had to be large enough to accommodate estimated levels of flooding or were restricted in their storage capacity. For Terrace, that meant being able to absorb and slow 60,000 cubic feet per second of storm-induced runoff.
“There was no way we could pass it; our spillway was too small,” Reinhardt says. The Terrace Irrigation Company didn’t have the money to build up the spillway, so the state put a storage restriction on the reservoir in the 1980s. Although Terrace has a capacity of just over 15,000 acre feet, the top 2,000 acre feet has been left empty, awaiting a flood, for nearly 30 years. “We have a reservoir and we can’t use the whole thing,” says Reinhardt. “That’s kind of a shame.”
About a decade ago, the nonprofit Alamosa Riverkeeper partnered with Terrace Irrigation Company. The nonprofit wanted to secure water that could be released below the reservoir to improve riparian health and supplement the river during low flows; the irrigation company wanted to build a new spillway.
Together the organizations raised $4.5 million for spillway replacement. The Alamosa Riverkeeper helped secure $2 million in Natural Resource Damage settlement funds related to the Summitville Mine, which were instrumental in leveraging a $1.5 million Water Supply Reserve Account grant and $1 million Colorado Water Conservation Board loan. With funding in place, Terrace agreed to donate the 2,000 acre feet of storage space to the Alamosa Riverkeeper’s project to hold water for instream flows. To date, the Alamosa Riverkeeper, with technical assistance from the Colorado Water Trust, has acquired more than a third of the water rights it needs to fill that space and transferred them to the Colorado Water Conservation Board’s Instream Flow Program.
Without the partnership, storage would have been nearly unattainable for her group, says Riverkeeper Cindy Medina. She estimates the 2,000 acre feet of existing storage space at Terrace is worth about $15 million.
Today the spillway is complete, and awaiting approval for the storage restriction to be lifted. Terrace Irrigation Company won’t receive any additional storage for irrigation purposes, but that doesn’t mean the project is without benefits for everyone. Between riparian health, aquifer recharge, and keeping the streambed wet so less irrigation water is soaked up and lost, most irrigators seem to be on board with the idea, Reinhardt says. “There’s a lot of common ground on what people want. It’s a matter of thinking creatively and coming up with solutions.”
To the northwest, at the headwaters of the Rio Grande, the San Luis Valley Irrigation District has formed a similar partnership to manage the Rio Grande Reservoir, which it owns and operates.
The Rio Grande Reservoir can store just over 52,000 acre feet of water. Water held there is used for irrigating 62,000 acres farmed by about 170 landowners—plus meeting the terms of the Rio Grande Compact; controlling floods; and now, in the past few years, storing water for Colorado Parks and Wildlife to benefit recreation and the environment. It also holds water used to offset well depletions for the San Luis Valley Water Conservancy District and the Rio Grande Water Conservation District’s first groundwater management subdistrict.
These newer storage and operating agreements keep the reservoir filled to a higher level for more months of the year than when it is used just for irrigation, exacerbating dam seepage issues on the 100-year-old reservoir’s north side. All dams have seepage issues, says Smith, the district’s superintendent, but this could be unsafe. When the reservoir is used just for irrigation, it will fill to 80 percent of capacity after spring runoff but fall back down to less than 20 percent by late fall. “We’re changing the historical carryover storage pattern that we’ve seen in the past,” Smith says.
Fixing the dam will be a $25 million rehabilitation project, says Smith. The state has approved $20 million in combined loan and grant funding through the Colorado Water Conservation Board, but to provide the remaining funds for the project, the district’s board has been open to forming new partnerships and leasing storage space—prompting further operational changes.
Nearby, on the south fork of the Rio Grande, lies the 4,400 acre-foot Beaver Park Reservoir, owned and managed by Colorado Parks and Wildlife. Beaver Park’s 100-year-old dam is also in disrepair and in need of rehabilitation. Since dam safety issues were discovered in 2010, the reservoir has been kept half-full.
During the 2002 drought, the San Luis Valley Irrigation District began talking with Parks and Wildlife about a partnership where the Rio Grande Reservoir would store more water imported by the agency from streams in the neighboring Southwest Basin. The two entities would jointly operate their systems to manage that water, while also facilitating the reservoir drawdowns necessary to make repairs.
By 2004, they initiated a temporary storage agreement, and since then, Parks and Wildlife has stored as much as 8,000 acre feet of water in the Rio Grande Reservoir. The agency is able to better coordinate releases and keep streambeds wet for wildlife, while still meeting the needs of domestic and agricultural water users. “It’s about rethinking, re-administering and re-timing reservoir operations,” says Smith.
Before establishing a permanent operating agreement, the reservoir managers have been testing their ideas and working in tandem to make some repairs. The Rio Grande Reservoir will install a clay lining to control seepage in 2013; also in 2013, Beaver Park will be drained and its spillway repaired.
“[The Rio Grande Cooperative Project] is built on this idea of a partnership in how to operate these two reservoirs for multiple benefits,” Smith says. “It’s revolutionary because it causes people to rethink how we’re doing business.”
Readying Storage for Subdistricts
The Santa Maria Reservoir Company feels pressure to meet some of the same emerging needs as the San Luis Valley Irrigation District. The company owns and manages the Santa Maria and Continental reservoirs, sending 90 percent of the stored water into the Rio Grande Canal and 10 percent into the Monte Vista Canal. Another 100-year old system, the reservoirs and the 8-mile conveyance channel between them are in need of repair, which is becoming increasingly apparent as the reservoirs store more water for replacing well depletions, says the company’s manager, Jay Yeager.
The Continental Reservoir holds about 22,500 acre feet, but is currently restricted to two-thirds of that. The Continental sits above the Santa Maria, which is nearly double in size. Both are fed by Clear Creek, just northeast of the Rio Grande Reservoir. Water is delivered to the Santa Maria Reservoir via the 8-mile-long conveyance system, which includes a 7-foot-diameter pipeline and open ditch. Water stored in both reservoirs is used to irrigate about 70,000 acres divided among 225 stockholders.
The Continental and Santa Maria were built to meet the needs of irrigators in the early 1900s, but new uses have emerged. Since Subdistrict No. 1 was formed and the first official efforts were made in 2012 to require local well owners to replace a percentage of their groundwater use to nearby streams, the Santa Maria Reservoir Company has been storing water used to offset those groundwater depletions. The reservoir’s stockholders are paid well for leasing their supplies and also want to see the subdistrict succeed, Yeager says.
The reservoir company has a two-phase project planned. They hope to first repair supports on part of the conveyance pipeline to ensure the structure won’t fail and finish lining the open canal portion with concrete so the reservoir can capture as much water as possible. Then they will fix a seepage issue in the Continental dam by replacing the liner. They will also add a new spillway— that repair will remove the restriction so the reservoir can fill to capacity. The reservoir company received approval in March 2013 for $1.8 million in Colorado Water Conservation Board funding—broken into a 25 percent grant and 75 percent loan—clearing the way for the first stage of repairs to begin soon.
“We’ll be able to store another 12,000 acre feet,” Yeager says. “They proposed six or seven more subdistricts in the San Luis Valley; some will probably need storage too. Not knowing where the water will come from, we want to have our facility all ready to go to be able to do what we need to do.”
Back at Platoro Reservoir, Nathan Coombs continuously seeks to improve the system’s ability to meet the needs of its irrigators. Platoro is newer than most reservoirs in the San Luis Valley; it was built starting in 1949, after the Rio Grande Compact was signed. The compact limits the Conejos Water Conservancy District from storing water in Platoro unless there’s more than 400,000 acre feet of water in Elephant Butte, a compact-related reservoir in New Mexico.
Uses haven’t changed much along the Conejos River since Platoro was built, but the ability to store water has. In the 1990s, the district obtained a direct flow decree— transferring the point of diversion for precompact irrigation water rights along the river so they could be stored in the reservoir and used later in the season. Without that direct flow decree, Platoro would continue to store little water.
The district has also been focused on modernizing to improve efficiency. With support from the Rio Grande Basin Roundtable and Colorado Water Conservation Board, local ditch companies and the district have together received three-quarters of a million dollars in state Water Supply Reserve Account funds—all to further the more precise allocation of water that comes with better gauging and automatic headgates. “It’s more surgical. Now we’re looking at where our problems really are,” says Coombs.
This is important when you’re stretching water as far as it can go. “The drier it gets, the harder it is to deliver water,” Coombs says. “We have got to do something or else we keep falling farther and farther back.”