Local Waters Alternative to the Lake Powell Pipeline 2.0

In the Local Water Alternative 2.0, WaterDM proposes measures and policies to improve water demand management in Washington County into the future. 

Download the policy here

Washington County’s Water Future: A Local Approach

Washington County, Utah, is at a critical juncture regarding its water supply. For years, the proposed Lake Powell Pipeline Project has been positioned as the solution to meet future water demands, aiming to deliver 86,249 acre-feet (AF) of water annually from Lake Powell to supplement local supplies. WaterDM’s “Local Waters Alternative 2.0,” argues for a more sensible, cost-effective, and resilient path forward: optimising local resources and aggressively managing water demand.

The Troubled Waters of the Lake Powell Pipeline

The Lake Powell Pipeline is an expensive and uncertain future supply. With an estimated cost of £1.45 billion (US$2 billion) and rising, its repayment is heavily reliant on potentially inflated population growth and water demand forecasts by the Washington County Water Conservancy District (WCWCD). If these projections don’t materialise, the financial burden on current and future Washington County residents will be significantly higher.

Furthermore, the pipeline’s reliability is highly questionable. The notion that the Colorado River and Lake Powell offer “the most reliable water supply in the Western US” is simply untrue, as the entire basin is severely impacted by climate change and faces increasing conflict and competing demands from six other basin states and multiple nations. The Virgin River and the Colorado River are intrinsically linked climatologically, meaning low flows in one are likely to coincide with low flows in the other. This renders the pipeline a poor choice for system diversity or redundancy. The pipeline also faces substantial legal and political risks, with neighbouring states already requesting that the Bureau of Reclamation block its environmental impact statement.

The Local Waters Alternative 2.0: A Robust and Resilient Path

The “Local Waters Alternative 2.0” offers a better option by focusing on available local water supplies and implementing cost-effective water demand management policies. This approach provides a more certain, resilient, and robust long-term supply compared to the Lake Powell Pipeline, with significantly lower cost and less risk.

The revised supply portfolio for Washington County, without the Lake Powell Pipeline, provides a reliable future supply of at least 111,212 AF of culinary (potable) water and an ongoing 15,693 AF of secondary water. This is considered sufficient to meet anticipated future demands.

Key components of this local water supply strategy include:

• Utilising the Virgin River System: Utah claims the entire contents of the Virgin River and Kanab Creek, giving Washington County local control over this resource, unlike the federally managed and over-appropriated Colorado River. Existing supplies, including Virgin River rights and local projects, already amount to 121,905 AF. Additional potential includes 23,200 AF from agricultural conversion, and a substantial 50,000-150,000 AF or more from other surface and groundwater rights not fully reported in the DEIS.
• Capping Secondary Water Systems and Treating Future Secondary Water to Culinary Quality: This involves capping existing secondary water systems at their current size and treating proposed future secondary water for potable use, aligning with trends across the Western US to reduce outdoor water use. Non-reverse osmosis (non-RO) treatment processes, such as ozonation and biologically activated carbon filtration (O3/BAF), can produce high-quality culinary water at significantly lower costs and without brine waste streams, offering a cost-competitive alternative.
• Storing Virgin River Water in High-Flow Years: Developing systems to divert and store water opportunistically during wet years, especially through underground storage like aquifer storage and recovery (ASR), would maximise utilisation and provide a robust backup during droughts. Washington County already has a successful groundwater recharge program at Sand Hollow, providing access to 100,000 AF of stored water.
• Expanding Wastewater Reuse: Additional wastewater reuse capacity has been proposed and planned, with estimates suggesting up to an additional 15,000 AF per year could be developed, providing a valuable future supply cushion.

Realistic Water Demand Management for a Sustainable Future

A cornerstone of the Local Waters Alternative 2.0 is a realistic water demand forecast and effective water demand management. The Draft Environmental Impact Statement (DEIS) is criticised for presenting an inflated and unrealistic demand forecast by failing to account for ongoing water efficiency after 2045, improperly inflating secondary water demand, and projecting high, unchanging system water loss. The DEIS assumes new customers will be as inefficient as existing ones for 35 years.

In contrast, the Local Waters Alternative 2.0’s forecast, using the same projected 2075 population of 594,660, includes ongoing efficiency improvements for existing customers and assumes new customers will be water-efficient from the start due to building and landscape codes. This revised forecast predicts a total per capita demand of 183.5 gpcd (gallons per capita per day) in 2075, with potable demand at 146.4 gpcd. This level of use is comparable to Grand Junction, Colorado, today, and significantly lower than the DEIS’s 240 gpcd forecast.

Washington County’s current water use is notably high compared to other Western US cities, largely due to the comparatively low cost of water for high irrigation use. For example, customers using 40,000 gallons in Washington County pay hundreds of dollars less than those in peer communities, with secondary water being even cheaper. Despite the WCWCD spending approximately £1.75 million (US$2.4 million) on conservation from 2016-2019, per capita water use in Washington County actually increased in that period, indicating that current programmes are not effectively reducing demand.

The Local Waters Alternative 2.0 recommends a series of measures to overhaul demand management, aiming for a 1% annual per capita reduction in water use, a typical improvement achieved by water providers across the US. These measures include:

• A Regional Approach to Water Demand Management: Fostering coordination between WCWCD and municipalities, akin to campaigns like Denver Water’s “Use Only What you Need,” to cultivate a new culture of water efficiency.
• Strengthening Development and Landscape Codes: Ensuring all new construction is water-efficient from the start, requiring EPA WaterSense fixtures and annual outdoor water budgets based on irrigable area.
• Water Budget-Based Rates: Implementing customer-specific water budgets and tiered rate structures to make excessive outdoor water use significantly more costly, providing both informational and financial incentives for conservation.
• Water Loss Control: Reducing real and apparent water losses in culinary and secondary distribution systems to 8% over the next 60 years, with annual, validated public audit reports.
• Incentivising Gradual Transformation to Climate-Adapted Landscapes: Redirecting conservation funds to a well-planned landscape transformation programme with loans, grants, and cost-sharing, focusing on existing landscapes and high-visibility areas to shift the culture around outdoor water use.
• Incentivising Toilet Replacement for Low-Income Customers: Targeting existing multi-family and low-income customers for toilet replacement, alongside advocating for legislation requiring only high-efficiency fixtures to be sold statewide.
• Customer Leak Detection and Abnormal Usage Alerts: Deploying advanced metering infrastructure (AMI) or incentivising consumer-level leak detection devices to rapidly identify and alert customers to leaks, which account for about 10% of indoor residential water use.

Conclusion

The “Local Waters Alternative 2.0” offers Washington County a sufficient, resilient, and robust local water supply option that is far less vulnerable and risky than the proposed Lake Powell Pipeline. By optimising local resources like the Virgin River, expanding water reuse and storage, and implementing comprehensive, realistic water demand management strategies, Washington County can meet its future population’s water needs, ensuring sustainable growth without incurring massive, uncertain costs or engaging in contentious interstate water disputes. This approach is not only fiscally responsible but also ecologically sound, reflecting a crucial adaptation to the arid environment of the Western US.