We’re getting better at tracking and altering flows on the fly. What does that mean for the future of water management?
On an unseasonably warm day in February, Jason Smith stands in a cramped shack in the parking lot of the Coors Brewing Company in Golden, Colorado, examining two instruments on the table in front of him. The shack is just feet from the banks of Clear Creek, the stream Smith administers as water commissioner for District 7 of the South Platte Basin. Clear Creek flows from the Eisenhower Tunnel near the Continental Divide all the way to the confluence of Interstate 70 and Interstate 25 in Denver. Along with Coors, the creek’s major water users include a smattering of agricultural producers and cities like Golden, Lakewood, Thornton, Northglenn and Arvada.
Both instruments in front of Smith are water gauges, and by the looks of them they could have been produced within a decade of each other. Yet when it comes to efficiency, the two devices are light-years apart. On the left is a chart recorder, which uses an inked needle connected to a float in a stilling well below to record changes in the creek’s water level on a piece of graph paper. Powering it on requires winding a knob on the front, and although this particular recorder is out of commission, it has been kept in place for posterity. On the right, by contrast, is a Sutron data logger, a small blue metal box that takes digital water level readings every 15 minutes from the float in the water beneath it and transmits those to a modem mounted on the wall. The modem beams readings out once an hour over the cellular network, and they are picked up on a state database viewable by anyone with an internet connection.
To Smith, the difference between these two devices amounts to hundreds of hours of time saved per year.
When he started as a water commissioner in Greeley in 2006, he spent countless hours each week traveling to remote stream gauges, manually reviewing chart recorder readings and transferring them to computer spreadsheets. Today, he simply wakes up and logs on to his computer at home, where he finds data from 44 gauges streaming into a spreadsheet that uses river levels to determine which water rights are in priority that day. Even when he’s out in the field, he can view every gauge remotely from the comfort of his pickup truck, using a tablet and a mobile Wi-Fi hotspot.
“Before, I had to wake up at 4:30, drive an hour and a half or two hours in the morning, go physically look at every gauge, drive home, look at my water rights priority sheet to determine what everyone could take that day, and then start calling people and telling them what to divert,” says Smith, a sturdily built 38-year-old with a thick beard who wears Oakley sunglasses, jeans and work boots. “What used to take me two and a half hours, I can now do in 15 minutes.”
Over the last decade, as remote sensing, wireless transmission technology, and computer modeling has improved, it has become easier and cheaper than ever to monitor and even alter streamflows in near real time. Smith’s story is a clear example: With remote stream gauges that transmit data to online databases, busy water commissioners can administer rivers more accurately, quickly spotting shortages or excesses and moving to address them. Yet the advances go far beyond stream gauging. Complex modeling tools allow those same commissioners to better account for unseen forces like groundwater depletion and accretion, preventing injury to senior water users and allowing excess water to be traded quickly. With online data management tools, members of multi-partner water projects like the Water Infrastructure and Supply Efficiency Partnership (WISE) south of Denver can divvy up shared water supplies in a matter of hours. And images captured from satellites, drones or airplanes and verified with remote sensors let farmers indirectly gauge the consumptive use of their crops, providing valuable data for future water sharing agreements.
Today, these tools are in use on scattered stretches of river across Colorado. Expanding their use throughout entire river basins could improve water management and provide the foundation for nimbler water trading markets of the future, which many say are needed to cope with growing scarcity. Yet doing so will require navigating a raft of challenges, from scarce funding and disparate data collection techniques to cultural concerns about data sharing and the generally decentralized nature of water management in the West.
The dashboard approach to water management
When Jason Smith took over as water commissioner on Clear Creek in 2014, he inherited a stream with just two gauges equipped with telemetry, which enables the transfer of remotely collected data over satellite, radio or Wi-Fi networks. One gauge was near the top of the creek, the other was near the bottom, and administering the more than 40 diversions in between required visiting and monitoring each headgate in person.
Smith knew the cost of remotely monitoring flows was falling. A plan allowing a data logging machine to transmit over the cellular network costs less than $10 per month, and open source software has lowered the cost of building databases and online dashboards to display remotely collected water data. In 2015, Smith used $131,000 in Colorado Water Conservation Board (CWCB) grant money to equip 44 stream gauges on Clear Creek with telemetry.
Using the CWCB funds and working evenings and weekends, Smith, his deputy Don Baggus, and the Colorado Division of Water Resources’ South Platte River Operations and Compact Coordinator Brent Schantz dug holes, poured concrete, and rigged up solar panels and cellular modems up and down Clear Creek. It took seven months, but when they were done, nearly all of the creek’s stream gauges were accessible in near real time on the internet. Gauge readings are updated every hour and listed on the Colorado Division of Water Resources website. They’re also accessible through Colorado’s Decision Support System’s HydroBase Data Viewer, alongside data from other gauges operated by the state, the U.S. Geological Survey, the Army Corps of Engineers, the Bureau of Reclamation, and individual water providers.
In working to modernize the gauges on Clear Creek, Smith was driven by the fact that without remote streamflow monitors, it took hours to respond to shortages or to redistribute water if there was excess due to a rain event. Whether a water user was diverting more than his or her share or foregoing diversions entirely, Smith needed to be able to react more quickly to get water to those in priority on a given day.
“Everything comes down to money,” Smith says. “Water is valuable, and if I let a drop of water go by that my users are entitled to just because I didn’t see it, that’s my fault.”
These days, Smith spends less time in the truck visiting gauges, although he still stops by each gauge once a week to make sure that it’s properly calibrated and that no snakes, mice or debris have touched a float and altered its readings. Instead, he prioritizes visiting long-neglected diversion structures on the creek or getting to know water users he hasn’t met before. And as water development in the basin continues, remote, real-time monitoring allows Smith and other commissioners to keep up—and take care of the water users along Clear Creek—without hiring as many new staff.
Accounting for unseen flows
Overseeing a stream like Clear Creek, where water is tight and surface water diversions account for most water use, is difficult enough. But in the lower South Platte Basin, the basic job of a water commissioner—matching supply and demand in accordance with the prior appropriation system—has an added layer of complexity. That’s because the river’s alluvial aquifer connects groundwater and surface water flows, so that a well that pumps miles from the river can eventually affect the river itself. To avoid harming senior surface water right holders, well owners band together and adopt augmentation plans, detailing how they will replace their well depletions with releases of surface water from reservoirs or groundwater recharge ponds. The plans vary depending on factors like a well’s distance from the river and the structure of the aquifer beneath, but with more than 400 augmentation plans in place across the basin, administering the river to account for both surface water diversions and the accretions and depletions of groundwater is an immensely complex task. To make matters even more difficult, water users are required to report their well pumping to the state just every 30 days.
Until recently, determining whether well owners on a given stretch of river were replacing enough—or too much—water to compensate for their pumping meant poring over scores of individual well decrees and augmentation plans, a process that could take hours. Administering wells so close to the river that they affect surface water flows in less than 30 days was even more difficult, since water commissioners were often forced to take well users at their word about how much they were pumping or replacing until the end of the month, when accounting came in.
In spring 2017, thanks to the release of a computer model called the Alluvial Aquifer Accretions and Depletions Analysis Tool (AAADAT), it became much easier to account for unseen flows on a near-real-time basis. The tool combines thousands of individual well decrees and augmentation plans into a single database, allowing water commissioners to see with a few clicks of the mouse whether depletions match accretions on a particular stretch of the South Platte that day.
“The commissioner can say, ‘Okay, I’ve got 16 people telling me they’re replacing 25 cubic feet per second on this reach of river today,’” says water engineer Kelly Close with Leonard Rice Engineers, who built AAADAT for the Colorado Division of Water Resources. If the tool reveals that replacements aren’t covering depletions, the commissioner can call individual water users to figure out who is not replacing enough.
The tool has an added benefit: It can notify water users almost immediately when they have “excess accretions,” meaning they are putting more water back in the river than is needed to satisfy the water rights in priority that day. Excess accretions exist because augmentation tools like groundwater recharge ponds cannot be “turned off,” but instead seep continuously into the groundwater aquifer. On days when the recharge water they supply is not needed to satisfy a call on the river, the owner of a recharge pond can—with the approval of the division engineer—market that water to a user downstream or divert more into recharge to take advantage of excess accretions. Until the advent of AAADAT, though, water commissioners could rarely approve exchanges of excess accretions fast enough to capture them before they flowed downstream to Nebraska.
Though a robust market for the exchange of excess accretions has not yet materialized, an analysis by a nascent group called the Northeast Colorado Water Cooperative estimated that there may be between 15,000 and 30,000 acre-feet of excess augmentation water available for leasing in the lower South Platte Basin each year. The cooperative, headed by Joe Frank of the Lower South Platte Water Conservancy District, is aiming to serve as a clearinghouse for the exchange of excess augmentation water. As that market develops, water commissioners will rely on AAADAT to verify the excess water being traded actually exists, and that the trades taking place do not harm other water users.
AAADAT has been rolling out in the spring and early summer of 2017, but there are obstacles to its implementation. For one, to function correctly, private well owners must enter reams of their historical well-pumping and augmentation data. In addition, the owners of wells and augmentation structures close enough to the river to affect surface water flows in less than 30 days will likely have to install real-time gauges on their wells and recharge ponds. Those gauges will send data directly to the AAADAT program so water administrators can verify in real time—and before monthly accounting arrives—whether users are meeting their augmentation obligations or have excess augmentation water to trade.
“The impacts to the river from well pumping can go back 20 or 30 years, so inputting that data is going to be time consuming,” says Schantz.
Enabling complex water-sharing schemes
If remote sensing and computer modeling have improved real-time management of both surface water and groundwater, they’ve also enabled complex water infrastructure projects that would be virtually impossible to administer without such technologies. The Water Infrastructure and Supply Efficiency (WISE) Partnership between Aurora Water, Denver Water, and 10 members of the South Metro Water Supply Authority, which is scheduled to begin water deliveries to some members in mid-summer 2017, is a case in point. WISE builds on the $638 million Prairie Waters Project completed by Aurora Water in 2010. Prairie Waters pumps reusable transbasin diversion water from the lower South Platte River to Aurora’s Binney Water Purification Facility. From there, a portion is reused by Aurora, while the rest is piped to WISE members in the South Metro area through the WISE pipeline network. According to Rick Marsicek, director of engineering for the South Metro Water Supply Authority, this reduces his members’ reliance on non-renewable Denver Basin groundwater by satisfying about 10 percent of their overall water demand, while the reuse of WISE water will satisfy additional demand. The WISE Water Delivery Agreement specifies that Aurora and Denver must provide an average of 7,225 acre-feet annually over a 10-year period to the other WISE members, who buy a share of the total flow through pro-rata subscriptions. Yet the amount that Aurora and Denver put into the system varies depending on available supplies, so WISE members may need to adjust their project intake valves as often as once per day.
Coordinating those flow changes, meeting the needs of all 10 WISE members, and facilitating water trades between them is the goal of a tool called the WISE web portal, which was developed by Leonard Rice Engineers and debuted when the project began operating this summer.
“There is a whole lot of complexity in this project, and through years and years of negotiation, this tool came to the fore as something we needed right at the onset of operations,” says Logan Burba, water resources engineer at the South Metro Water Supply Authority.
“There are ways we could manage this system without a tool like this, but this tool will make our lives much, much easier, keep our lines of communication very clean, and hopefully reduce the potential for human error.”
Here’s how it works: Early in the morning on days when Aurora alters the amount of water they are supplying to WISE—an event known as a flow change—the web portal sends an email to WISE members, notifying them of the share they are entitled to and asking how much they want, whether they plan to use it for direct use or for storage, whether they plan to execute any water trades with other WISE members, and how much pipeline capacity they need to move their water. When members take less than their full share and do not designate their water to another member, unallocated water automatically flows into a surplus pool in the web portal, where other members can request it.
After a flow change and once every member has requested their desired water and capacity, the web portal locks them out and the South Metro Water Supply Authority reviews all requests to ensure the system can handle them. Some trades between members at opposite ends of the project, for instance, may not be possible due to limited pipeline capacity. The web portal then exports a list of valve set points, which an operator enters to remotely adjust the intake valves of every WISE member. For billing and tracking purposes, each intake valve is separately metered and each member gets a monthly bill.
Remarkably, on the day of a flow change this entire sequence of events—which involves up to 15 players selecting from a long list of interdependent variables—is completed by mid-afternoon. Since Aurora and Denver can change the quantity of water they provide to WISE members daily, the WISE web portal is critical in enabling members to quickly respond.
“This project exists to provide renewable supplies to an area that has been highly reliant on groundwater for a long time, and this tool gives members the ability to look at their systems in real time and understand how things are working,” says Mark Mitisek of Leonard Rice Engineers, who helped develop the WISE web portal. “It also allows WISE members to more easily take advantage of times when there is excess supply or move quickly to allocate limited supplies in times of shortage. It’s hard to imagine how WISE would work without a tool like this.”
Tracking water from above
Precise, real-time water management is vital in water-sharing agreements of all kinds, from multi-lateral partnerships like WISE to efforts to share water between agriculture and other uses. In recent years, technology companies have sprung up to help farmers carefully track their water use and quantify consumptive use savings from techniques like rotational fallowing, crop switching, or deficit irrigation, all of which free up water that an irrigation district or ditch company can then lease directly to municipalities.
“You can’t get paid for what you don’t track, so data is key,” says Kevin France, CEO of SWIIM System, the operating company affiliated with Denver-based technology incubator Regenesis Management Group.
France’s firm operates in Colorado, Arizona and California and makes an on-farm planning and water tracking package called SWIIM that allows farmers to enter data on their fields, soil types, crops, planting dates, and historic water use. Using that information, the software recommends ways to save water.
To document a farmer’s water budget, SWIIM uses a wide range of remote sensors, from pipe sensors that measure inflow to the farm to soil moisture monitors to a custom-built tailwater sensor that gauges water flowing off a field. Yet the company also takes advantage of aerial monitoring technologies that use multi-spectral cameras mounted on drones, planes or satellites to indirectly measure things like plant health and evapotranspiration, the amount of water taken up and released by plants as they grow.
One major provider of multispectral imagery is the U.S. Geological Survey, whose Landsat satellites orbit the earth every eight days and provide a snapshot of changes in water use by plants on the ground. In western Colorado’s Grand Valley, that data may soon be used to help verify the consumptive use savings achieved in a water banking pilot project underway during the 2017 growing season. A coalition of municipalities and nonprofit groups are paying growers there to fallow a portion of their land and leave their unused irrigation water in the river to help replenish water levels in Lake Powell. Landsat measurements—verified by remote sensors on the ground—could help determine how much water these temporary fallowing agreements actually save, and thus their potential to affect the river basin more broadly if expanded.
“The information that can be gleaned from Landsat has tremendous potential to tell us how much water crops are actually using, versus how much is being diverted,” says Perry Cabot, research and extension leader at Colorado State University’s Western Colorado Research Center. “There are a number of management questions you can answer once you know that. If a farmer is interested in participating in a transfer, both the farmer and the recipient of that water can look at a map and understand how much transferable water could materialize.”
Aside from improving the accuracy of water use estimates, Cabot says, aerial tools like Landsat also provide a system-wide, bird’s-eye view of water use in Colorado that is tough to get given the decentralized nature of water management in the state. “On the Western Slope, we are divided by so many ditch companies and so many entities managing water that it’s very hard to get a handle on how much water crops are consuming,” he says. “The ability to scan broad swaths of land lets you overcome that to some degree.”
Taking real-time management basin wide
There are clear benefits to the kind of real-time, precise water management made possible by current technology: It enables better river administration with fewer resources, allows water users to adapt more quickly to water shortages or excesses, aids in the tracking of unseen phenomena like groundwater flow and evapotranspiration, and permits large and complex water-sharing schemes to function.
Why, then, has such management not been deployed across Colorado and throughout entire river basins?
There are a range of reasons. Although the cost of remote water-monitoring technology—from data loggers to modems to cameras—is falling, Colorado lacks a dedicated funding stream to pay for installing, maintaining and replacing it across the state. CWCB grants like those employed by Jason Smith to install telemetry on Clear Creek can cover some up-front expenses, but technology inevitably malfunctions, fails or falls victim to vandalism, requiring repair or replacement.
“I have a couple of spare solar panels and a couple of spare data loggers, but if something broke tomorrow we would have to go begging to the water user who relies on that data for money to replace it,” says Schantz, the South Platte Basin water commissioner. “We have to find a way to fund this technology more permanently.”
The basic structure of Colorado water administration is another obstacle. Technologies like Landsat imagery provide a landscape-scale snapshot of estimated evapotranspiration, but in a state where water is managed by individual ditch companies and municipalities, it is unclear how data crossing jurisdictional boundaries would be maintained, interpreted and used.
To illustrate this point, Cabot contrasts water management on the Western Slope of Colorado with management in California’s Imperial Irrigation District, a major agricultural breadbasket. Both areas encompass hundreds of thousands of irrigated acres. “There is one front door to the Imperial Irrigation District,” he says. “Their control center looks like an air traffic control room, with 50 monitors tracking the movement of water across the district. On the Western Slope, we have hundreds of entities monitoring and moving water around using everything from telemetry to ditch riders in their pickup trucks. The decentralization makes investments of scale and scope very difficult.”
Any effort to share real-time water data must also account for differences in the way it is collected by water users. Municipalities, for instance, might employ distinct methods of collecting water data at the household or apartment building level. Some states define the use of water as the amount diverted, while others define it as the amount consumed. Yet water managers say that such differences in methodology and terminology can be overcome if they are accounted for when data is shared. Perhaps more daunting are the cultural norms of water management, where privacy is prized and data sharing is sometimes viewed as risky, since any shared data can theoretically be used against you in a future legal battle.
Even these attitudes, long held by water providers, are being challenged by new technology, as Landsat imagery makes detailed water use data available to the public without data sharing agreements or consent.
“With Landsat, you can see on a basin-by-basin basis how much certain crops are using right now,” says Ted Kowalski, who leads the Colorado River Basin Initiative at the Walton Family Foundation, whose grants have recently targeted water data advances. “There are tools out there to get this information. That makes water providers less hesitant to share it themselves.”