City of Aurora – A Metro Growth Magnet Builds Its Water Future through Strategic Investment, Innovation and Hard Work

By: Rich Anderson

The City of Aurora (CO) joins with Denver and Lakewood to form one of 381 Metropolitan Regions in the United States. Aurora’s is a major contributor to the metro economy. The US economy added 2.3 million jobs in 2016; and Metro areas generated over 2 million, accounting for more than 95% of all US gains. The Denver‐Aurora‐Lakewood Metro area ranked 18 out of 381 Metro areas in annual employment growth. (1) Growth in employment is expected to follow rapid population growth. Projections indicate Aurora’s population will double from 359,407 in 2017 to three quarters of a million people by 2070. These growth trends require more public services and modern infrastructure to deliver them. In a high prairie desert city any mayor and council will address water supply and demand, now and in the future. Steve Hogan, Mayor of the City of Aurora says, “We don’t sit around and wait. We take action.” Mayor Hogan and city leaders are making decisions based on local priorities – survival and quality of life – as they identify, commit funding, and sequence major capital investments and operations logistics to keep the water flowing.

An early May 2017 interview with Mayor Steve Hogan and Marshall Brown, Director of Aurora Water, in the impressively modern and expansive Aurora Civic Center, revealed a legacy of forward thinking about water needs. Aurora now employs an ever-evolving mix of advanced water management planning tools to achieve an adequate supply at constant demand regardless of population

growth. The diversification of water supply is necessary but nonetheless logistically challenging. This review describes how a 20th Century legacy articulated by elected leaders became the cornerstone for advanced water supply planning by today’s leaders; and what they are doing now to secure their water future.

Legacy of Water Self Reliance

Aurora experienced a severe 3-year drought in the 1950s, and city leaders made the decision to become water self-reliant to ensure drought resilience. This led Aurora officials to break away from supplies delivered by neighboring Denver Water; and by the 1960s created its own system designed to withstand the record drought.
Several important guidelines for water self-reliance were established by city leaders that still guide city initiatives to secure an adequate and safe water supply:

• Climate varies so develop supply projects in several basins
• Develop a system of primarily surface water supplies
• Non-tributary groundwater should be used only in drought conditions
• The supply should be sufficient to withstand the drought of record

The summary strategy is simple – diversify the water supply (surface and groundwater supplies; multiple water basins, etc.), and invest in redundant systems in anticipation of upset conditions. Easy to articulate the strategy, but it requires a Rubik’s Cube solution to achieve because the water management infrastructure is diverse, and managers face several headwinds.

Aurora Water Infrastructure

Aurora acquired significant surface water rights, entered into numerous operating agreements and constructed various pipelines, reservoirs, and water treatment plants to create a water system able to meet the City’s water needs consistent with Council goals.

Treatment: Aurora Water currently operates three potable water treatment facilities, (see Table 1). One or more of these plants will be expanded to meet peak demand projections in the future. Aurora Water also operates one reuse facility: Sand Creek Water Reclamation Facility (Sand Creek). Sand Creek currently provides up to approximately 5 million gallons per day of reclaimed water to parks and golf courses throughout the city.

Table 1: Aurora Water Treatment Plants

Potable Water Treatment Facilities Capacity in MGD
Griswold 80
Wemlinger 80
Binney 50
Due to operational factors, the daily rate is less than plant capacity.

Storage:
Aurora currently has a storage capacity of over 150,000-acre feet (AF) in 12 reservoirs and lakes (2). The reservoirs serve to make the water system more efficient in the management of its yields, which vary seasonally and annually.

Distribution:
Aurora Water maintains over 1,600 miles of pipeline, nine booster pump stations and eleven finished water holding tanks. Aurora’s service area consists of eight pressure zones, the majority of which are gravity fed.

Service Area:
As of 2015, Aurora Water served some 351,200 people with approximately 81,500 connections. Most of the customer accounts consist of single‐family detached units; and the remainder of accounts are with single‐family attached, multi‐family, commercial, municipal and irrigation only units.

Navigating the Headwinds

Rapid Population Growth and Forecasted Gap in Supply:
The Metro basin region is projected to face a water supply gap by 2050. Population projections used by Aurora indicate a doubling of the City’s population, and a potential local water supply gap by 2070.

Limited Natural Water Sources:
Aurora gets 15.9 inches of precipitation per year. The US average is 30.2 inches of precipitation. (3) Aurora, like many of its neighboring arid cities, must rely on capturing melting snowpack as well as rainfall for water supply. But the snowpack source presents many physical and logistical challenges that would limit source water, if not for innovative engineering.

Water Rights:
Rain and snowpack water sources eventually feed the region’s streams, reservoirs/lakes and aquifers. These sources are subject to pre-existing water rights and interstate compacts established over many decades. Aurora cannot just appropriate all the water flowing through its borders. “Aurora diverts water from Colorado’s streams and aquifers in a manner prescribed by water right decrees adjudicated by Colorado’s Water Courts. Aurora owns or leases water that is subject to 50 decrees that include over 150 individual water rights.” (4)
Precipitation and stream flow levels vary considerably over a broad geographic area. Where Aurora has water rights the city “…has made substantial capital investments in remote sensing technology including over 20 data collection platforms that access satellite Systems to relay current information to city’s water control centers. The delivery of real time stream flows and supplemental data is vital to the protection and administration of Aurora’s Water rights.” (5)

Evaporation:
Aurora currently stores 150,000-acre feet (AF) in 12 reservoirs and lakes. The reservoirs serve to stabilize supply, especially because of seasonal and annual precipitation variability. The duration of storage, however, presents an efficiency challenge due to high rates of evapotranspiration (water loss) from surface supplies (e.g., reservoirs and streams). Aurora Water must manage the flow of the water to minimize water loss in storage and transportation, which can be as much as 6 percent. Therefore, demand management and operational efficiencies in the storage and flow of supplies for consumption.
Aurora is addressing these headwinds with due diligence, while maintaining fidelity to the guiding principles. Water supply for the future depends on diversifying sources, managing demand intelligently/efficiently, and “…working well with neighbors”, said Mayor Hogan.

Water Supply: Spreading the Risk – Supply Diversification

Taking advantage of local and regional natural resources is critical to Aurora’s water future success. Place-based (local) water planning relies on a good understanding of source water and what is needed to convey it to useful purpose and protect the quantity/quality of the water. Obtaining water supplies from only one basin is risky because drought in the high plains regions is not uniform for all basins.
Actions were taken to diversify the water supply by developing surface water supplies in 3 basins – see Table 2. The nearby South Platte basin comprises nearly half of the supply. The Arkansas and Colorado basins make up a little over 25 percent each.

Table 2: Water Supply by Basin

River Basin Acre Feet/Year
Arkansas 21,905
Colorado 22,521
South Platte 40,848
Total 85,274
1 Acre Foot = 325,850.943 gals

Demand Management and Local Water Conservation

City leaders developed municipal water conservation programs and policies in the 1980s, and they have grown over the last nearly four decades. Aurora initiated programs involving consumer household audits; rebates for conservation plumbing; public education; and ordinances curbing consumption when conditions trigger conservation measures.
The city website contains the 2015 Municipal Water Efficiency Plan (2015 Plan) which describes successful results from initiating water conservation measures. One result was that the reduction in per capita use per day (gpcd) offset increased demand from population growth. Mayor Hogan describes this as “consistent demand”. The relation between supply and demand is balanced by either increasing the volume of water, or conserving and/or reusing or recycling water. But Aurora is doing both at the same time through strategic acquisition, informed demand management, and innovative storage and retrieval technology and engineering.
The 2015 Plan incorporates water efficiency goals to reach future estimated reductions in
household consumption. The 25-year goal calls for a 10% reduction in water use system wide with 45% of that coming from single family residential and 35% from multi-family customers.
Water Director Marshall Brown described some of the innovative partnering arrangements Aurora Water has developed to target water efficiency measures. 150 of the top water users in the city were identified: Aurora City, hospitals, schools and university, Air Force base, major residential subdivisions. Aurora Water partners with these users by installing individualized meters to document consumption to use as a base for measuring conservation potential.

Innovative Supply Diversification: Prairie Water Initiative – Water Reuse

A 2002-2004 drought prompted Aurora leaders to obtain additional raw water supplies to augment current supply to increase reliability. The Prairie Waters program was designed to provide an additional raw water supply to drought-harden the existing water portfolio. The program relies on reusing already decreed, fully-reusable water rights. Aurora has the right to recapture water imported from the Colorado and Arkansas Rivers. Additional supplies come from converted agricultural rights and lawn irrigation return flows.
The system collects, stores, and pumps water from the South Platte River using a riverbank filtration collection, an aquifer recharge and recovery system, three pump stations, a 34‐mile 60‐inch diameter pipeline. The recovered water enters the Binney Water Purification Facility, a state‐of‐the‐art water treatment facility. A finished water pump station provides for distribution to customers.
Aurora began delivering recaptured water under the Water Infrastructure and Supply Efficiency partnership, or “WISE”. The WISE water delivery agreement is a collaboration of neighbors in a cooperative project between the City of Aurora, Denver Water, and the South Metro WISE Authority (South Metro). A primary goal of the WISE project is to reduce South Metro’s dependence on nonrenewable groundwater. Aurora and Denver provide additional supplies delivered through unused or underused capacity in the Prairie Water projects.

Wastewater and Water Reclamation

Aurora also manages stormwater and wastewater in the city, and it relies on over 700 public and private stormwater ponds to retain flood waters to protect water quality. Most of Aurora’s wastewater is treated by a regional district, the Metropolitan Wastewater Reclamation District. The wastewater collection system includes over 1,000 miles of pipeline, six major interceptors, and twelve lift stations. The Aurora wastewater collection system also includes various “…interties and agreements with bounding districts that jointly make the best use of infrastructure discharging to Metro”. (6)
Aurora Water also operates the award-winning Sand Creek Water Reclamation Facility (Sand Creek). The Facility has been in operation since 1968, and is one of the oldest operational plants in the region. (7) A portion of the city sewage enters Sand Creek, solids are separated from liquids, and approximately 5 million gallons of reclaimed water per day is delivered back to the system. The non-potable reclaimed water has been reclaimed and used for nearly 4 decades to irrigate parks and golf courses throughout the city.

Comments

Aurora Water recently completed its first Integrated Water Master Plan (IWMP) to ensure that the water demand of customers continues to be met at a reliable and safe level now and into the future. The Plan brings all of the water supply, physical plant (above and underground infrastructure), operations and water distribution under one control umbrella.
Taking the long-view, Aurora has certainly established the independence sought by past leaders to become self-sufficient in its water supply. Yet, they appear to be continuing to evolve from independent provider to regional collaborator. On the path from dependent, to independent actor to regional collaborator there are some key lessons worth recognizing:

• Aurora Water learned to understand consumption by sector (agriculture, urban household, industrial use, etc.), and geography (location of water source and water consumption).
o This knowledge allowed them to explore opportunities within each sector, and sometimes each major consumer, to gain water rights, initiate operations/exchanges to conserve and/or reuse, and satisfy sector demand through technology efficiencies and reuse/recycling.
• The limitation of surface water storage and retention time and the coordinated movement of water to stanch loss is a logistical challenge that can be mastered.
o Retention and conveyance of surface water supplies is an issue as losses (evaporation seepage, etc.) reduces supply, sometimes by as much as 20 percent.
• Consider capital investments in underground storage to avoid evaporation and to build up unused supplies for possible emergency use in record droughts
• Recognize neighboring communities are in the same race to provide water supplies for the future, even though they may be at various stages of achievement and effort, and find ways to work together to address a regional issue.

Mayor Hogan emphasized that cities with adequate water, and the information to prove it, help its bond ratings. Aurora’s just increased, according to the Mayor, including the water debt. The city has an excellent repayment schedule in part due to consistent policies at the local government level.

REFERENCES
1. U.S. Metro Economies: Past and Future Employment Levels May 2017, Prepared for: The United States Conference of Mayors and The Council on Metro Economies and the New American City Prepared by HIS Markit
2. 2015 Municipal Water Efficiency Plan Aurora Water, Prepared for: Colorado Water Conservation Board 1313 Sherman St, Room 718 Denver, CO 80203; Prepared by: Aurora Water, Lyle Whitney and Melissa Grove 15151 E. Alameda Pkwy, St 3228 Aurora, CO 80012, Appendix B.
3. https://currentresults.com/Weather/US/average-state-precipitation.ph
4. 2015 Municipal Water Efficiency Plan Aurora Water, p. 3.
5. 2015 Municipal Water Efficiency Plan Aurora Water, p. 3.
6. 2015 Municipal Water Efficiency Plan Aurora Water, p. 5.
7. Aurora Water; https://www.auroragov.org/residents/water/water_system/water_treatment/reclaimed_water/

About the Mayor – Steve Hogan

Profession: Being the mayor of the city of Aurora is a full-time job as defined by the City Charter.
Education: Bachelor of Arts, University of Denver
Community/Intergovernmental: Aurora Chamber of Commerce and the Aurora Economic Development Council. In addition, Mayor Hogan serves on numerous boards and authorities such as Adams County Economic Development Council, E-470 Public Highway Authority, Fitzsimons Redevelopment Authority, United States Conference of Mayors, and Visit Aurora.

About the Director – Marshall Brown
Marshall Brown is the Director of Aurora Water, where he oversees more than 440 employees, an annual operating budget of approximately $135 million and a five-year capital projects budget of about $410 million. His areas of responsibility include potable and reclaimed water, wastewater and storm water. Brown has more than 20 years of experience in the water industry. He began in the private sector, where he gained significant technical expertise on water resource evaluation and development, feasibility studies, groundwater modeling and groundwater characterization and remediation.
He was previously the head of the water utility in Scottsdale, AZ. He accepted his current position as Director of Aurora Water in 2012. During his time with these two industry leading utilities, Mr. Brown has had the opportunity to plan, manage and direct activities to position each organization for sustainable futures. These activities have included helping create diversified water portfolios, planning/implementing/managing emerging technologies (such as reverse osmosis, aquifer storage and recovery and riverbank filtration), communicating/managing through multiple strategic efforts (rate increases, drought restrictions, fee methodology changes, etc.) and policy discussions/creation on a local, state and national level.
Brown received a Bachelor’s of Science degree from Brigham Young University in Geological Engineering and a Master’s of Science degree from the University of Arizona in Geophysical and Geological Engineering.