A WISE Project for the Denver Metro Area
Article by Tracy Kosloff, MWH Global
On November 24, 2009 three representatives, David Bennett of Denver Water, Joe Stibrich of Aurora Water, and Rod Kuharich of South Metro Water Supply Authority (South Metro) presented an overview of the Water, Infrastructure and Supply Efficiency (WISE) project to the AWRA Colorado Section.
The WISE project is an effort to enhance the reliability of water supplies for the Denver Metro area by using excess system capacities and unused reusable water. The main components of WISE are:
- reusable water from Denver Water and Aurora Water, and
- excess capacities in the Aurora Prairie Waters Project and the East Cherry Creek Valley (ECCV) pipeline
Aurora and ECCV, one of the South Metro members, soon will both have the capability to convey water from the Brighton area to the southeast Metro area. Aurora and ECCV would have first use of their system capacity; the excess would be available to Denver Water and other South Metro members. Preliminary engineering shows that in addition to reserved deliveries to Aurora and ECCV, as much as 15,000 acre-feet per year could be delivered to Denver as a strategic reserve and as much as 60,000 acre-feet per year could be delivered to South Metro, on average.
WISE would have the following major benefits to each of the partners:
- Access to unused supplies and access to water in the South Platte River downstream of Denver
- Potential for the use of WISE supplies to replace their current “Strategic Water Reserve” in mountain reservoirs
- Efficient use of ECCV system and other regional infrastructure
- Reduce reliance on groundwater
- Minimize need to purchase new water rights
- Efficient use of Prairie Waters Project system
- Offset cost of Prairie Waters and future water rights purchases
So, how would the WISE project operate? The amount of WISE water available to the partners would vary from year to year. However, in most years Aurora and Denver excess return flows would be available for treatment and delivery to a master meter through the Prairie Waters Project and the ECCV pipeline. Aurora would use more of the Prairie Waters system capacity in the summer and during dry years; however, water would at least be seasonally available to South Metro. In extreme conditions such as drought or an outage in their system, Denver Water may use their reusable supplies via WISE. In those years when little water is available through WISE, South Metro would rely on their other supplies including storage and groundwater. The fact that South Metro has an alternative supply to return to as needed creates a unique fit that makes for efficient use of water and infrastructure and avoids shortages.
Although WISE appears to be a win-win-win, it is not without challenges. One daunting challenge is obtaining agreement and commitment from the partners, which is not simply the three parties, but 15 when each of South Metro’s members is considered. The WISE partners must agree on each of their water demands and structure an equitable payment system for the joint project. The partners need a firm grasp of how much water each entity will use and under what conditions they will want to use it. They will also need to analyze the pros and cons of any available supply options. The partners are working through these issues and it is hoped that water delivery agreements can be negotiated by the time Aurora’s Prairie Waters Project is online in 2011.
Detailed engineering and water rights analyses for the WISE project are ongoing. In addition to the available reusable supplies, the partners are considering purchasing supplemental agricultural water rights and investigating rotational fallowing opportunities. To get the most out of the WISE project 40 years into the future, additional infrastructure needs to be in the ground, including additional pipelines and a new terminal storage reservoir, planned for the south end of Aurora’s Prairie Waters system. The attached WISE presentation includes some maps of the current and potential future infrastructure.
WISE will require political support both from local governments associated with the partners and other water interests both within the Metro area and on the West Slope. The partners recently made information on the project public. Reaction has been positive so far.
Eric Hecox Chief of CWCB’s Water Supply Planning Section said,
“I think it is great that Aurora, Denver Water and South Metro are coming up with regional solutions to water problems. Around the state, many people feel that we need to use the water that is available in the Denver area. The goal of WISE to capture and reuse fully consumable return flows makes the most of water supplies that are located nearby. The project would squeeze as much efficiency as possible out of the water and water systems that the Metro area already has.”
Eric also noted that WISE can help fill the gap between water supply and demand identified in the 2005 Statewide Water Supply Initiative (SWSI) report. SWSI assumed that Metro area water suppliers would be able to implement all of their planned projects, and even so, there would be a need for additional water. WISE was not considered at the time SWSI was published, and could help address the future need.
Eric Kuhn, General Manager of the Colorado River District, was hopeful about the WISE project. He said that every drop of water that is legally reused on the Front Range is considered an advantage on the West Slope.
Rod Kuharich feels that South Metro’s members see a real benefit to solving their water supply problems through a regional approach. “It is a long time coming, but finally the major water providers have recognized that each one of us would benefit from this collaboration.”
Mark Pifher, Director of Aurora Water, has stated that “the cost of infrastructure is too great, and the water supply too scarce to think that such regional opportunities can continue to be ignored.”
Chips Barry, Manager of Denver Water, said “it is important for utilities to work together to avoid permanent water shortages in the metro area. The WISE Partnership can help to make all of the Partners water supplies more reliable.”