What is the Water Supply Plan?

The Water Supply Plan is an analysis of the city’s water supply needs. This plan is driven in coordination with the city’s Comprehensive Plan which outlines how much and what type of developments will occur across the city, Water Conservation/Efficiency Plan which sets out water conservation goals and strategies, and Drought Management Plan which is the city’s planned response to water supply shortages.

Water Supply Plan Goals

  1. Identify how much water the city’s system can produce.
  2. Identify how much water our community needs in the Comprehensive Plan’s time horizon (2040).
  3. Identify the risk of water supply shortfall.

Water Supply Plan Analysis

Through industry-leading modeling, this Plan evaluated not just one model run - but millions of model runs to evaluate a full range of possible futures providing greater understanding of water supply variability and resiliency moving forward.

This model looked at how much water the city’s system could produce with varying climate conditions by looking at weather cycles back to the late 1500s. Demand for water was modeled by reviewing water usage on the city’s 33,000 accounts considering land use, indoor and outdoor uses and age of construction.

Scenario Planning

The model described above was then used to plan for a number of changing variables to get a better picture of the full range of possible futures. The key variables included:

  • Land Development and Redevelopment. Adding or changing development types can impact how much water the City will need. The City is largely built out with only 5-10% of the land in the City available to be developed and a similar amount that could potentially be redeveloped. How much impact does this remaining area have on the ultimate water needs of the community?
  • Water Conservation Trends. The City is seeing a slow decrease in water demand over time. Can water conservation trends significantly impact the ultimate water needs of the community?
  • Climate Change.   In general, climate change models show the Front Range will likely have increased temperatures over the next 20 to 50 years. Increased temperature can affect a number of different aspects of the water cycle, particularly the amount of water that would be available to the city, the timing of when that water is available, and the amount of water needed to irrigate outdoor landscaping.

Results

Under expected baseline conditions which assumes development is completed largely in line with the existing Comprehensive Plan map, water conservation trends continue, and Wattenberg Reservoir is completed, there is sufficient water to support the water needs of the community at buildout.

Important takeaways include:

  • Drought is the greatest threat to the city’s water supply. The city’s water supply can very by as much as 11,100 acre-feet depending on weather and drought management activities.
  • Conservation measures by customers are the best way for the city to secure its water supply. Adding or changing development types can impact how much water the City will need. Moving to a high-conservation, xeric-landscaping future could save the City between 3,690 acre-feet and 4,200 acre-feet depending on land use trends. Moving to a low-conservation future would cost the city between 8,660 acre-feet and 9,343 acre-feet depending on land use trends; increased demand of this magnitude would result in significant water supply shortfalls.
  • In a future scenario with a weak economy and land use less dense than is anticipated in the current Comprehensive Plan, the City would save between 930 acre-feet and 1,435 acre-feet. If the city becomes significantly more dense than is anticipated in the current Comprehensive Plan, the City would spend an additional 1,340 acre-feet to 2,020 acre-feet more water. This quantity of water impact is not insignificant, but it is not as impactful as conservation trends.
  • Climate change is not a major driver of ultimate water needs. As we learn more and climate change models improve, additional study in this area will be needed.