A Sustainable Water Supply for Colorado

Many have tried to provide Colorado with a sustainable water supply. But it’s a tough job. Colorado suffers from long-term aridification, and its steady population growth also presents a challenge. How can policymakers come up with a new source of water for Colorado?

Although the state has done much to manage water more efficiently, experts say it can still do more. The state needs new reservoirs to store water for dry times. Some also contend that it is time to ban “thirsty grass lawns.” New technology promises to measure snowpack more accurately for the sake of better planning of agricultural activity, and cities are working to “buy and dry” agricultural land in order to divert water to cities as farmers grow crops that need relatively little water.

But gains derived from greater efficiency cannot really be regarded as providing a new source of water.

New Sources of Water

As water scarcity becomes an increasingly pressing global issue, the search for new sources of water has led to innovative approaches. One such approach is water reuse, which involves collecting, treating, and reusing wastewater for various applications. Additionally, desalination of seawater and the utilization of brackish groundwater offer alternative sources of water, highlighting the diverse strategies available to address water shortages.

Water Reuse. Although reuse of water (also called recycling or reclamation of water) also increases efficiency, it is generally considered a water source in its own right. Wastewater from many sources can be collected, treated, and reused in such non-potable applications as irrigating farmland and landscapes, recharging groundwater, washing and reducing dust, flushing toilets, and blowing down boilers.

More intensive methods of treating wastewater make even sewer water safe to drink. The required process is called direct potable reuse (DPR). 

DPR involves collecting wastewater, removing solids and contaminants through filtration and treatment processes, including reverse osmosis and advanced oxidation, disinfecting the water, and undertaking post-treatment measures. The purified water, meeting drinking water quality standards, is then distributed as a reliable and safe drinking water source to address water scarcity or improve water management practices.

In November 2022, the Colorado Water Quality Control Commission established regulations governing such reuse. When we think about water that was once sewer water, our reaction tends to be “Yuck!” But all water has been recycled countless times by natural processes anyway. DPR simply speeds up the process and improves the water quality of existing water systems.

Whether used for potable applications or non-potable applications, DPR is a reliable source of water. In any human community or industry, there is wastewater, and the water can be reused over and over.

Desalination. Desalinated water, which is derived from the process of removing salt and other impurities from seawater, is considered a nontraditional source of water. In the case of Arizona, a state like Colorado that is located far from any coastline, policymakers are exploring the idea of desalinating seawater as a potential solution to their water supply challenges. The concept involves building a desalination plant in Mexico, where access to seawater is readily available, and constructing a pipeline to transport the desalinated water to Arizona.

The proposed project reflects the recognition that water scarcity knows no geographical boundaries, and innovative measures are necessary to meet the water demands of arid regions. While desalination plants are typically built in coastal areas, the idea of constructing a facility in Mexico and establishing a cross-border pipeline demonstrates the willingness to explore unconventional options.

Unsurprisingly, many consider the project to be a pipe dream. In any case, why not desalinate water that’s already here?

Brackish Groundwater. Seawater is more difficult to desalinate than brackish groundwater. Brackish groundwater refers to underground water sources that contain a moderate level of salinity, typically higher than freshwater but lower than seawater. It is a mixture of fresh and saltwater found in aquifers and wells in various regions. Brackish groundwater is considered a valuable alternative water source that can be treated and utilized for drinking, irrigation, and industrial purposes, particularly in areas where freshwater resources are limited.

In the United States, brackish groundwater is plentiful, even far inland. In fact, “The amount of brackish groundwater in the United States is about 800 times greater than the total amount of groundwater withdrawn nationwide for all uses….” So it is unnecessary for residents of Colorado and other states to seek out seawater to desalinate.

New Sources of Funding

Public-private partnerships (P3s) enable infrastructure to be built even in areas with no access to the kind of capital it normally takes to develop major public infrastructure. Under P3s, infrastructure is operated like a concession and is maintained by the company that builds it. So a city does not retool its utility and train or retrain staff in order to accommodate newer and more efficient plants.

In Alice, Texas, the first P3 of its kind in the west will make possible a new plant that desalinates brackish groundwater. The partnership will lower the cost of the city’s water without costing taxpayers a cent. This model can be emulated throughout the west, wherever there is brackish groundwater, which exists even in landlocked states like Colorado.

Sometimes utilities and policymakers neglect the possibility of desalinating water because they regard it as too expensive. But it costs much less to desalinate brackish water than to desalinate seawater. Moreover, significant reductions in the cost of reverse osmosis desalination that were achieved in Israel several years ago are now lowering the costs of desalination globally. So it’s time to take another look at desalination.

With the right technology and a little outside-the-box thinking, it may be possible to create a new water supply for Colorado or at least significantly expand the existing supply.