How thirsty is Douglas County? #Water providers work to transition to renewable sources — #Colorado Community Media #RioGrande #SouthPlatteRiver

Rueter-Hess Dam before first fill. Photo credit: Parker Water & Sanitation

Click the link to read the article on the Colorado Community Media website (Elliot Wenzler):

On an average day, 25 people move to Douglas County. Each one needs to drink, shower, water their lawn and wash their dishes. The full impact of that growth is difficult to see, but it’s easy to understand: more people need more water. And in a county where thousands of homes rely on a limited supply of underground aquifers, water providers are constantly working to shift to more sustainable resources before they run out.

Denver Basin Aquifer System graphic credit USGS.

Some aquifers buried under Douglas County have lost two to six feet in depth of water. Local water providers have noticed their supply wells aren’t producing like they once did.

“It’s like sucking water out of the bathtub with a straw,” said Rick McLoud, water resources manager for Centennial Water & Sanitation. “There’s only so much water in the bathtub and the sooner you suck it out with a straw, the sooner it will be gone.”

[…]

To meet those demands, water providers are planning a mix of conservation efforts, wastewater projects and new infrastructure for renewable resources of water. The county government is also looking at how to bring in more water and is considering spending a portion of their $68 million in federal funds from the American Rescue Plan Act on the issue.

‘Overreliance on groundwater’

As Douglas County’s development has surged since the 1990s, many of the largest communities such as Parker and Castle Rock have relied on groundwater to fill residents’ bathtubs and sinks, said State Engineer Kevin Rein…Groundwater from aquifers makes up about 65% of the water used by Parker Water and Sanitation, which is the provider for Parker and parts of Lone Tree and Castle Pines, and by Castle Rock Water. Centennial Water uses about 20% groundwater. Those ratios can change depending on drought conditions…

Douglas County sits on a layer of several aquifers, including the Arapahoe, Denver, Dawson and the Laramie-Fox Hills aquifers. Most major water providers use the water in the Arapahoe and Denver aquifers, which reach depths of 1,700 and 600 feet beneath the ground, respectively…

Under Douglas County’s guidelines for development in unincorporated areas, only the western part of the county is not allowed to rely on their groundwater for development, said Steve Koster, assistant director of planning services for the county. Those communities must provide either a renewable water source or use groundwater from the eastern part of the county. Koster said the county is not actively looking at requiring or incentivizing developers to instead look for renewable resources of water…

Parker Water and Sanitation is working on a project that will partner with a water conservancy district in Sterling, a town in eastern Colorado, to capture unused water during high runoff years from the South Platte River there and store it to pipe back to the town. The project won’t impact existing water rights and won’t allow buy-and-dry of nearby agriculture, Redd said. In order to meet Parker’s projected water demands, the project will need to be complete by 2040, Redd said. That project would get Parker Water to 75% renewable water and would provide water for more than 300,000 people in Douglas County, including in Parker, Castle Rock and portions of Castle Pines and Lone Tree, according to a project proposal. Castle Rock Water is a partner on that project.

Over the next 20 to 30 years, Castle Rock plans to invest about $500 million in renewable water projects including new pipelines, additional storage and water rights. Marlowe said the reason they spread out those projects over time is to keep rates for their customers down. By 2050, Castle Rock plans to move to 75% renewable and by 2065 have a 100% renewable system for wet or average years.

Dominion Water and Sanitation, which serves about 1,200 homes in Sterling Ranch, plans to be 90% renewable by 2040. Sterling Ranch is slated to add about 11,000 more homes to their community in that same time period at a rate of 450 homes per year. Dominion also plans to include about 700 other existing homes from smaller communities to their service area soon. Right now, Dominion is 100% renewable but is set to drill wells in the Cherokee Ranch area to blend some groundwater into their system, making it more drought-resistant, Cole said. They are also planning to build a river intake on the South Platte River and a wastewater treatment facility, which will provide at least 1,600 acre-feet of water per year to Sterling Ranch…

Castle Rock plans to incorporate programs in the coming years that encourage more efficient utilities and lawns that don’t require heavy irrigation. At the statewide level, a bill being considered by the legislature this session would pay residents up to $2 per square foot to rip out their irrigated turf and replace it with less thirsty alternatives. Sterling Ranch has focused on a program they call “demand management” that allows residents to have a live look at their water usage and bills…Their community also has banned the use of bluegrass, a type of turf that demands lots of water. Instead they offer a variety of drought-resistant plants for landscaping…

A view of public lands around the Sangre de Cristo Mountains and just south from the area Renewable Water Resources has proposed a wellfield for water exportation. Photo credit: Alamosa Citizen

As the commissioners consider how to approach the issue, $68 million in federal funds has the potential to aid in addressing the water demands of a growing community. One proposal for the money, which the commissioners have dedicated six two-hour meetings to discussing, would pump about 22,000 acre-feet of water per year to Douglas County from the San Luis Valley. Renewable Water Resources, the private company proposing the project, says that’s enough for 70,000 houses. The project has been met with ire from many in the valley, though, as multiple water conservation districts and elected officials there have said they don’t have enough water to spare and it would damage their agriculture-based economy…So far, all the major water providers in Douglas County have said they are not interested in using the water from the RWR proposal. Darling says that’s in part because many providers have already heavily invested in other projects…

Commissioners have also heard presentations from Parker Water, who asked them to consider using about $20 million of the federal funds to help their South Platte River project, and Dominion, who asked for help funding their regional wastewater plant in partnership with Castle Rock Water and the Plum Creek Reclamation Authority.

Study previews how #ClimateChange may alter rain-making atmospheric rivers by 2100 — NOAA

Photo credit: NOAA

Click the link to read the article on the NOAA website (Theo Stein):

The people, economy, and ecosystems of the Pacific coast states of California, Oregon and Washington are highly dependent on cool-season atmospheric rivers for their annual water supply. These long, narrow flows of saturated air can transport enormous amounts of water vapor – roughly equivalent to the flow at the mouth of the Mississippi River. They can unload heavy precipitation on the Cascade and Sierra Nevada ranges, but their annual yield regularly swings between boom and bust.

When atmospheric rivers, or ARs, fail to materialize, droughts often follow – especially in California, where they account for over 50% of the total annual precipitation. Anticipating future climate-induced changes to AR patterns is therefore exceedingly important. Global models, however, do a poor job of simulating precipitation over the complex terrain of coastal and inland mountain ranges. Now, a new NOAA study using data generated by regional climate models and published in the journal Climate Dynamics suggests climate change will likely alter atmospheric rivers in ways that will make managing water more difficult.

“These high-resolution climate simulations showed something we hadn’t seen before, which was decreased future precipitation amounts across many mountainous regions of the western United States,” said lead author Mimi Hughes, a research scientist in NOAA’s Physical Sciences Laboratory.

Atmospheric rivers can be both beneficial — when they provide water to fill reservoirs and build snowpack — and calamitous — when they generate so much precipitation over a short period of time that they cause flooding. Although numerous studies have investigated climate projections for atmospheric rivers, few have examined whether climate change would have a uniform impact on all events.

Downscaling climate models to better predict future impacts

For the new paper, Hughes and a team of Physical Science Lab and colleagues from CIRES and NCAR analyzed data from regional climate models simulating weather conditions over most of North America for the period 1950–2100. They specifically looked at the end-of-21st-century changes in integrated water vapor transport (IVT) events along the western US coast in three of the highest-resolution regional climate models. IVT is a measure of how much water vapor is moving through the air and was used as an indicator of atmospheric rivers making landfall.

Rather than evaluate the simulated impact on all model-generated atmospheric rivers, researchers partitioned the events into two categories – modest and extreme – and then looked for different outcomes.

Hughes said their findings are consistent with previous global climate model projections of increased lower-elevation precipitation across much of the western U.S. However, differences did emerge. The simulations projected moderate events to be less frequent and deliver less high-elevation precipitation, a finding that tracks another recent NOAA study.

A drier future for California’s most important “reservoir”?

The Sierra Nevada mountains are an irreplaceable component of California’s current water system. Snowpack in the high Sierras acts like a giant reservoir, releasing clean water during the melt season. Sixty percent of California’s water supply originates in the high Sierras. More than 75% percent of Californians drink water generated by Sierra snows.

Notably, more than half of the model runs in the new study showed that Sierra snowpack would receive decreased precipitation by 2100, while the arid Great Basin might benefit from a moisture boost.

This study suggests these two types of atmospheric rivers could change in different ways under climate change, with the beneficial kind becoming less frequent, Hughes said.

“While we did not specifically examine seasonal precipitation outcomes like droughts, it’s fair to conclude that if these projections bear out, California’s strained water resources may become even more challenging to manage,” she said.

For more information, contact Theo Stein, NOAA Communications, at theo.stein@noaa.gov.

#Nebraska gubernatorial candidate: Nebraska #water solutions shouldn’t harm #Colorado — The #Greeley Tribune #SouthPlatteRiver

Click the link to read the article on The Greeley Tribune website (Jeff Rice, The Fort Morgan Times). Here’s an excerpt:

Collaboration will yield a lot more South Platte River water for Nebraska than trying to finish a ditch that’s been abandoned for more than a century. That was the consensus at a freewheeling panel discussion in Sterling Monday afternoon as Nebraska Sen. Theresa Thibodeau met with water experts from Colorado to learn more about the water that flows into her state across the state line near Julesburg.

Thibodeau is a candidate for the Republican nomination for governor in Nebraska. Her visit was prompted a proposal by incumbent Gov. Pete Ricketts to finish digging the Perkins County Canal from the South Platte River near Ovid to a reservoir somewhere in Nebraska. The canal is allowed under the terms of the South Platte River Compact of 1923, and can divert up to 500 cubic feet per second out of the river. But without the canal, Nebraska can’t exercise that water right…

The panel consisted of Thibodeau, Bruce Gerk, a member of the South Platte Roundtable, Jim Yahn, manager of the Prewitt and North Sterling reservoirs, Don Chapman, manager of Riverside Irrigation District near Sterling, and Joe Frank, general manager of the Lower South Platter Water Conservancy District. Among the dozen or so attendees were Colorado Sen. Jerry Sonnenberg of Sterling, former state senator and agriculture commissioner Don Ament, Gene Manuello, vice president of the LSPWCD, and Logan County Commissioner Byron Pelton. During Monday’s discussion, Thibodeau made it clear that Nebraskans will do whatever is necessary to protect the water they now get and that they have a right o in the 1923 compact…

Yahn. Chapman and Frank gave Thibodeau a short course on Colorado’s water reality. The most important point, and one they stressed repeatedly, is that return flow and seepage from irrigation in Colorado is what makes the South Platte the year-round river it is today. Sonnenberg pointedly asked the panel what would happen to the multitude of water augmentation projects that operate during the winter months along the lower Colorado reach of the river if Colorado had to try to deliver 500 cubic feet per second into the Perkins Canal. Chapman said it was “very likely” that those projects, which replace water drawn out by pumps during the irrigation season, would be harmed, leading to curtailment of pumping. It also would probably diminish the return flow that ends up in Nebraska. Manuello said one of the worst myths about the river is the amount of water that flows out of Colorado. He said that, while it’s true spring runoff and occasional flooding send large amounts of water downstream, those events are of short duration and probably wouldn’t be available for use in the Perkins Canal.

#Arizona’s Future #Water Shock: Smaller cities. Soaring water prices. Scorched desert towns — Circle of Blue

Arizona monsoon cloud with lightning striking the beautiful Sonoran desert in North Scottsdale. Photo by James Bo Insogna. Title: Arizona Monsoon Thunderstorm. Taken on August 15, 2016. Used under a Creative Commons license.

Click the link to read the article on the Circle of Blue website (Keith Schneider). Here’s an excerpt:

What’s happening in the million-dollar homes of Rio Verde Foothills, one of the Phoenix metropolitan region’s choice places to live, is a future shock “buyer beware” scenario certain to be replicated over the next several decades in many other Arizona communities contending with urgent water constraints.

Bridges across the Tempe Town Lake on the Salt River in Tempe, Arizona. Tempe Beach Park in the foreground, and the building with HOPE on it at 350 W Washington St across the river. By Dicklyon – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=65090199

Another View

About 50 miles south, another scenario of 21st century Arizona is taking shape. The nearly 23,000-member Gila River Indian Community is modernizing: adding to its group of casinos, preparing to expand its irrigated farm acres, and elevating its influence in Arizona’s politics and economy. It’s doing so by virtue of one of the most secure and abundant water supplies in Arizona and the entire Southwest.

Following decades of brutal discrimination and abuse by white settlers and state authorities during which the two Gila River tribes’ rights to their historic water supply were not honored, Congress approved an agreement between the United States and the State of Arizona that essentially guarantees tribal access to 653,500 acre-feet of water per year…

…from previous statements by tribal leaders and in interviews with state water authorities, it is clear that the Gila River Indian Community, or GRIC, is using its abundant water to build a new age of wealth and influence on the 372,000-acre reservation south of Phoenix. GRIC is constructing a federally-financed irrigation network to increase farming operations to 75,000 ancestral acres from the current 35,000. It negotiated lucrative agreements to lease water to Phoenix, Chandler, and other communities. It is also marketing water that it stores in aquifers to willing suburbs and subdivision builders interested in long-term leases.

Since 2016, GRIC has played a central role in storing over 370,000 acre-feet of water in Lake Mead, plus 130,000 more acre-feet this year to keep lake levels high enough to prevent a water shortage declaration more dire than the one the federal government issued last August. GRIC received $274 per acre-foot from the state and federal governments. In short, ample and secure water supply is the basis of the community’s plan to rebuild the vitality of its 8,000 year-old desert civilization that was ruined in the 20th century…

Arizona’s Future Water Shock

The water-abundant and thriving Gila River Indian Community amounts to one bookend scenario of Arizona’s 21st century condition. The other bookend is the arid Rio Verde Foothills, where government decisions and meteorological disruptions trap residents in a water-related crisis that heat and drought aggravated, and state law did not anticipate.

In 1980, Arizona enacted an innovative groundwater management program intended to ensure adequate reserves of water for rapid home development and expansive population growth by designating four regions from Prescott to Tucson as Active Management Areas. (Santa Cruz, the fifth AMA, was carved out from the Tucson AMA in 1994.) The program included two important exemptions, however: its provisions did not apply to groundwater withdrawals outside of the AMAs. And within the AMA boundaries, owners of private wells that pumped less than 35 gallons per minute — in other words, many of the wells drilled for the state’s exploding residential real estate markets — did not come under state oversight.

In 1995, the law set in place a consumer protection measure to require developers building subdivisions in AMAs with six or more homes to assure buyers that their houses had a 100-year supply of water. But the requirement did not apply for residential construction projects with less than six homes. Builders constructing individual homes, or clusters of five homes or less in an AMA, avoided the 100-year water requirement. Outside the AMAs, groundwater safeguards did not apply, creating what amounted to a home construction free-for-all.

Little more than 40 years after the statute was enacted and less than 30 years after the 100-year assured water supply rules were adopted, the subdivision and private well waivers have resulted in Rio Verde’s emergency. They also influenced a boom in home construction that has caused — and continues to cause — thousands of wells to fail inside and outside of AMAs. It is clearer by the day that, without significant strengthening, the state’s water management program is becoming increasingly irrelevant. The emergence of serious instances of water shortage from Kingman in the north, to the Chino Valley north of Prescott, to Cochise County in Arizona’s southeast has prompted civic campaigns for reform. They have yet to attract sufficient legislative support.

That seems certain to change. And soon, because of climate change.

Ranking and time evolution of summer (June–August) drought severity as indicated by negative 0–200 cm soil moisture anomalies. Maps show how gridded summer drought severity in each year from 2000–2021 ranked among all years 1901–2021, where low (brown) means low soil moisture and therefore high drought severity. Yellow boxes bound the southwestern North America (SWNA) study region. Time series shows standardized anomalies (σ) of the SWNA regionally averaged soil moisture record relative to a 1950–1999 baseline. Black time series shows annual values and the red time series shows the 22-year running mean, with values displayed on the final year of each 22-year window. Geographic boundaries in maps were accessed through Matlab 2020a.

This year alone, the latest scientifically respected studies reveal a number of disconcerting findings. The megadrought that has Arizona in its tightening grip is the worst in 1200 years. Climate change is responsible for at least 40 percent of the decline in Colorado River water supplies. And the Southwest, like other desert regions, is getting steadily hotter, drier, and more dangerous. Though future weather conditions are always difficult to accurately predict, a worst-case scenario for Arizona looks like this: Population growth stops. Residents start to migrate in droves away from the stifling hot and dry state. Home values collapse. The state enters an era of relentless decline. By 2060, according to several published projections, extreme heat and water scarcity could make Phoenix one of the continent’s most uninhabitable places.

It’s not much of a reach to conclude that Arizona is at the intersection of two paths to the future. By mid-century it will be a model of desert dwelling resiliency. Or it will be a weakened civilization that is starting to waste away…

Taken as a whole, the data mean that Arizona’s share of the Colorado River will likely shrink to less than half the current 2.8 million acre-feet allotment. Arizona will rely much more heavily on its finite groundwater reserves to support population growth, residential construction, and new business starts that state officials continue to encourage. And though Arizona has stored over 13 million acre-feet of water underground to supplement supply during years of water shortage, never since statehood in 1912 has Arizona encountered such a long and deep period of water scarcity that science predicts will grow steadily more severe…

This year, the governor proposed establishing a new state agency, the Arizona Water Authority, to pursue new supplies and also asked the Legislature for $1 billion more, framing the request around the need to build a desalination plant, perhaps in Mexican waters, to produce 250,000 acre-feet a year.

Other ideas for securing Arizona’s water supply — regulating groundwater use in rural areas, metering private water wells, increasing use of recycled wastewater, restricting natural grass lawns, and imposing land use and urban design requirements to collect and store stormwater — haven’t reached nearly the same level of clarity and legislative purpose.

There’s a reason for that. Regulatory changes in water policy and practice are some of the steepest cliffs in Arizona’s political landscape. Any proposal judged by lawmakers to challenge property rights, raise costs, and impede growth is dead on arrival in the Legislature. Such proposals generate powerful winds of opposition in the executive offices of home builders, chambers of commerce, and every other economic development agency.