Conservation in Colorado

In a headwaters state with a semi-arid climate, water supplies are limited. Compounding matters, water demand across the state is high and only expected to grow: Colorado’s Department of Local Affairs (DOLA, 2015) projects the state’s population to nearly double to 8.6 to 10 million people by 2050. As Colorado’s Water Plan (State of Colorado, 2015a) points out, this population growth will create a significant need for an additional 600,000 to one million acre-feet (AF) of water annually to meet future municipal and industrial (including self-supplied industrial) demands. Furthermore, besides managing its own water security, Colorado must ensure approximately two-thirds of the water it produces annually passes out of the state for interstate and international legal obligations (Water Education Colorado [WEco], 2021).

According to the Statewide Water Supply Initiative 2010 (Colorado Water Conservation Board [CWCB], 2011), Coloradoans have the potential to save between 160,000 AF and 460,000 AF by 2050 through “active” conservation and another 154,000 AF through “passive” conservation annually.

Agricultural Water Conservation and Efficiency

Agricultural water is used for livestock and to irrigate crops, allowing the industry to generate approximately $5 billion in revenues annually in Colorado (WEco, 2021). Due to the state’s semi-arid climate, a significant quantity of water is necessary to sustain agricultural activities: of the total amount of water withdrawn or diverted statewide, approximately 86% goes to agricultural uses (WEco, 2016). In terms of consumptive use, agricultural water use accounts for 89% of the statewide total, or approximately 4.7 million AF (WEco, 2016; State of Colorado, 2015). While this is a significant amount of water consumptively used, the CWCB (2011) reports that crops grown within the state (as of 2010) could stand to use an additional 2 million AF in order to be fully irrigated. As the state’s water supply gap continues to widen, the number of irrigated acres is expected to decline 15-20% by 2050 due to urbanization and water transfers; however, agriculture is expected to continue to use the majority of Colorado’s water (State of Colorado, 2015).

There are several ways to increase efficiency in agricultural water use, as well as a number of opportunities to stretch water supplies to help meet future needs.

Municipal Water Conservation and Efficiency

Municipal water, often referred to as M&I water, is used by Coloradans in their homes, yards, businesses, firefighting, and (smaller) industry. Annual M&I deliveries from surface and groundwater sources account for approximately 7% of total statewide deliveries, and M&I consumes approximately 7% of all the water consumed in the state (WEco, 2016; CWCB, 2011; State of Colorado, 2015).

M&I use can be broken down into three categories: indoor use, outdoor use, and water loss in distribution systems. Historically, outdoor use (primarily landscape irrigation) has accounted for more than half of annual domestic water use in the state, but from 2006-2016 this trend has changed toward a division of 60% indoor use and 40% outdoor use (WEco, 2016). Indoor use varies considerably, depending upon the number of people in a household, plumbing fixtures, appliances, lot size, and other factors. The largest water users inside the home are toilets, clothes washers, faucets, and showers (CSU Extension). The pie chart below illustrates the typical household’s indoor use of water in Colorado (figure from CSU Extension).

Modeling from the 2010 Statewide Water Supply Initiative estimates that M&I has the potential to save 160,000-461,000 AF by 2050 through “active” conservation (CWCB, 2011). Additionally, another 43,000-61,000 AF of water could potentially be saved with more reuse of existing water supplies (WEco, 2016; CWCB, 2011). Based on population projections and under passive conservation, the CWCB (2011) estimates M&I water demands to increase from 975,000 AF to 1.36 million AF by 2035, and to 1.5 to 1.8 million AF by 2050.

Typical Household’s Indoor Use of Water in Colorado

Chart recreated from CSU Extension

Colorado Consumptive Water Use

Chart recreated from Colorado Water Plan (2015). Note that figures represent consumptive use (water permanently removed from immediate water environment) by each sector, and therefore are lower than total water withdrawn or diverted.

Commercial and Industry Water Conservation & Efficiency

Commercial and industrial water use is also commonly referred to as self-supplied industrial (SSI) use, because large industrial water users often have their own water supplies (separate from public water systems) or lease raw water from others (CWCB, 2011). Generally, water for industries is used for energy development, snowmaking, thermoelectric power generation, food processing, and large industries such as breweries.

Together these industries require approximately 1.1% of Colorado’s total annual deliveries, but business and industry also claim a substantial portion of municipal supplies (WEco, 2016; CWCB, 2011). Of the average 5.3 million AF consumed statewide annually, SSI consumes about 4%, or about 212,000 AF (State of Colorado, 2015). Due to the wide variety of water users within the SSI category, sub-sectors range from very high to very low water consumption (Kohli, Frenken & Spottorno, 2010).

Based on projections, the State estimates current industrial consumptive use to increase to between 236,000 and 322,000 AF by 2050, requiring an additional 48,000 to 134,000 AF annually to meet future demands (CWCB, 2011; State of Colorado, 2015). Within the past few years, a number of innovations have come to light for industrial users that have the potential to conserve not only water, but also energy. In order to assist in closing the looming supply gap, instituting these new innovations will require overcoming a number of hurdles, including increasing the understanding of options available, cost assistance in implementing the new technologies, and overcoming indifference in water pricing, among others (CWCB, 2016).