Greening Up: Cities Begin To Put Stormwater To Better Use

By Kathleen Ferris

Desert dwellers love a good rain, but cities long considered stormwater runoff a nuisance. Cities built massive infrastructures to drain it away quickly before it could flood streets and yards. In the Phoenix Metro Area most storm drain systems empty into washes and rivers, including the Salt and Agua Fria rivers.

Now the U.S. Environmental Protection Agency is pushing for change. The agency is encouraging cities to examine how they can put some stormwater to beneficial use through what EPA calls Low Impact Development.

Curb cuts help direct storm runoff into landscaping.

Curb cuts help direct storm runoff into landscaping.

Low Impact Development is any technique that allows more rainwater to stay in place and to sink into rooftop gardens, into landscaping and planters, and through sidewalks and parking lots made of permeable pavement. It’s rain harvesting on an industrial level and can restore washes and wetlands, enhance street-scapes and parks, and help cities cool down faster during evening hours.

Some cities expect the EPA to eventually stop encouraging Low Impact Development and make it mandatory. Professionals from the cities of Mesa and Glendale (with help from Logan Simpson Design and funding from the Water Infrastructure Finance Authority of Arizona) created the Low Impact Development Toolkit, which was published in April. The publication offers technical details about construction methods that make the most out of stormwater. Here are a few examples.

  • Cuts in a street curb can direct runoff into vegetated areas. There are a variety of cuts and drains that can help rainwater enhance landscaping, restore a natural wash or create a wetlands project. Retaining rainwater also helps plants grow faster and healthier, in particular trees.
  • Permeable paving allows rain to spread and sink into the soil beneath parking lots, sidewalks and playgrounds, keeping plants healthier and the surrounding area cooler. Permeable paving comes in a variety of looks, such as porous asphalt and concrete or paving stones.
  • Roof top gardens catch and use the rain and direct the runoff through downspouts to catchment areas below. Cisterns above and below ground collect rainwater that can be used later to water landscaping, rooftop gardens and wetlands.

Mesa and Glendale have used Low Impact Development techniques on several public projects and plan more. For example, Mesa used Low Impact Development techniques to redesign the street-scape near Fiesta Mall, along Southern Avenue at Alma School Road. Glendale used permeable paving in the Park and Ride lot at 99th and Glendale avenues.

Low Impact Development serves several purposes.

  • Stormwater is filthy, particularly in what city officials call “the first flush” of a storm. In the Valley, heavy storms pick up everything that’s been collecting for months on freeways, sidewalks, back yards, parking lots, and industrial sites. That’s why cities try to make sure that businesses store chemicals in closed containers above ground level, apartment building managers keep the lids down on their dumpsters, and dog walkers pick up after their pets. Not everyone complies. Low Impact Development would collect that first flush and filter it through sandy soil and vegetation to clean it.
  • Hard surfaces such as roads, sidewalks, parking lots and rooftops create a “heat island” over any city. These surfaces collect heat during the day and release it in the evening, heating the air and increasing temperatures. Turning a significant portion of hard surfaces to permeable or green surfaces would help to reduce the heat island.
  • Widespread Low Impact Development in a high-intensity development area can reduce the cost of storm drain repairs and expansions. For example, Mesa is expecting higher density development in its downtown core area once Valley Metro Rail arrives. The city wants to have a useful publication to encourage and help private developers use Low Impact Development methods.

The Low Impact Development Toolkit is not just for developers. The publication also includes ideas for homeowners. Check with your city’s water conservation office for classes, videos or publications available that show you how to put rainwater to better use around your home. The Watershed Management Group also offers information and hands-on workshops.

For 46 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit

Study: Western Cities Know How To Save And Reuse Water

By Kathleen Ferris

Along with thirty conservation leaders and experts in the southwest, I’ve been wrestling with a project since 2013. It’s part of the Moving Forward effort initiated by the Bureau of Reclamation and the seven Colorado Basin states that followed completion of the Colorado River Basin Water Supply and Demand Study of 2012.

The study confirmed that action is needed to prevent significant shortfalls of Colorado River water to meet demands in coming decades. The study also found that a wide range of solutions is needed, including municipal and industrial water conservation and reuse.

I co-chair a workgroup established in response to this study that has been investigating water use in ten large metropolitan areas that receive Colorado River water. These metropolitan areas include central Arizona, southern California, southern Nevada, and the Front Range in Colorado.

Our specific assignment: document conservation and water reuse efforts in these metropolitan areas over the last 25 years, highlight successful programs, and identify opportunities to build on these successes.

The workgroup’s conclusions can be summed up in simple math. If customers in these ten metro areas had continued to consume water as they did in 1990, demand for water would have been 1.7 million acre-feet higher in 2010 than it was. That’s a lot of water not consumed. One acre-foot is enough to serve 2.5 Phoenix households for a year. Screen Shot 2015-05-12 at 6.18.00 PM

There’s more. The workgroup found that all ten of the metro areas treat wastewater and reuse it for beneficial purposes. Together the ten areas reused a total of 709,000 acre-feet of water in 2012. Clearly, these metropolitan areas are making considerable progress in water conservation and reuse.

The workgroup also came up against a hard economic fact. Conservation and reuse may not result in substantial reductions in Colorado River water use in the future. The water cities save will be used to offset or delay the need for new water supplies to meet growth in these bustling metro areas that represent 20 percent of the country’s Gross Domestic Product and employ 20 million people.

The workgroup’s first task was to set realistic goals. We quickly decided that trying to compare one metropolitan area to another to measure water-savings was unrealistic. Here are some reasons why.

  • Lack of data: The workgroup found that comprehensive information on conservation and reuse implemented to date is not available. Each of the water providers within the ten metropolitan areas track information about their conservation programs differently. For example, water use in centralScreen Shot 2015-05-13 at 1.29.20 PM Arizona is tracked by the state Department of Water Resources based on reports that cities are required to file annually. We have been collecting that data for over 30 years. Most metro areas track their information separately. On top of this, there are no consistent accounting categories or definitions and that makes comparing efforts virtually impossible.
  • Different Demographics: Differences in median income, size and age of homes, and density of living units within each metro area have an impact on per capita water use. For example, metro areas with higher density housing and more apartments generally have lower water use per capita because the demand for landscaping is less. Those that have a higher percentage of older or rented single-family homes tend to have a higher per capita use than newer, owner-occupied homes.
  • Climate Extremes: Then there is weather. Climate varies significantly across the metropolitan areas. It is easy to see why outdoor water use is high in the Phoenix area, which receives only 7 to 11 inches of precipitation a year and where supplemental irrigation is required year-round. It would be hard to compare that to Denver’s outdoor use, when Denver receives 17 inches a year and landscaping is dormant a good part of that time.

The workgroup’s next task was to determine what had happened to water use in the metro areas since 1990 and what could be expected in the future. Here are two of our key findings:

  • The population in most of these metro areas grew over recent decades, but per capita water use has decreased, partially offsetting population growth. For example, the City of Phoenix’s population grew by 47 percent between 1991 and 2013, but its per-capita use rate decreased by 29 percent during that period.
  •  Water providers in these metro areas will continue to increase water use efficiency and reuse. Opportunities will vary depending on many factors, including public acceptance and cost of new water supplies.

As a final task, the workgroup identified potential actions to accelerate conservation efforts in these ten metropolitan areas. These actions include:

  • Increasing outdoor water use efficiency through technology improvements, behavioral changes, and low-water use landscapes.
  • Increasing the customer’s understanding of water use.
  • Increasing funding for water conservation and reuse.
  • Integrating water and land use planning.

Last week, Reclamation published the Moving Forward: Phase 1 Report, which includes chapter 3 detailing the workgroup’s efforts. It’s not hard to read and is packed with details and charts. It includes 44 case studies of conservation and reuse programs within the ten metro areas. It makes for some of the best reading in the report.

Our next job is to take action. The goal of Moving Forward: Phase 2 is to implement pilot projects based on potential actions identified by the workgroup. I guess it’s back to work.

For 46 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit

How To Save Water With 416 Acres Of Grass

By Kathleen Ferris

If you want to find out how to save water and keep a little grass in the back yard, how about asking a city with more than 400 acres of Bermuda to care for? The City of Scottsdale maintains 42 parks that include about 416 acres of grass. Six of the city’s largest parks are strung along Indian Bend Wash, an eleven-mile green belt that cuts through the heart of Scottsdale.

Chaparral Park in the Indian Bend Wash

Chaparral Park in the Indian Bend Wash

Indian Bend Wash is a community playground, but its first purpose is flood control. The wash moves and controls storm water to protect homes and businesses during heavy rains. The project was once envisioned as a concrete channel, but Scottsdale and the U.S. Corps of Engineers came together to build a green option.

The wash includes seven levies, is built using rainwater-harvesting techniques, and carries the outflow from surrounding storm water drains into the Salt River bottom. Grass and trees stabilize the ground in the wash, so it is not carried away during heavy storms and runoff.

Indian Bend Wash is home to a sophisticated weather station that indicates how much water the soil, grass, trees, and plants have lost during the day. The technology helps park supervisors know exactly how much water to apply to keep their parks thriving. That’s important because all park supervisors are given water budgets for the year that they are expected to meet or beat.

Here’s how that budget is determined: The Arizona Department of Water Resources regulates the maximum amount of water a city, a business or an HOA can use per acre of turf. The regulation applies to any area that has 10 or more acres of grass. Only eight of Scottsdale’s parks have 10 or more acres of turf, but that doesn’t matter to Scottsdale leaders. They beat the regulation for all of the city’s parks.

A Weather Station monitors water needs in Scottsdale parks.

A Weather Station monitors water needs in Scottsdale parks.

In 2001, the Scottsdale Parks and Recreation Department made it a goal to use 15 percent less water than allowed by the state’s regulation on turf in all 42 of the city’s parks. The city has an irrigation manager dedicated to accomplishing that goal. Here are six additional ways the city controls the amount of water used on its grass. These measures can help you with your lawn, too.

1. Watch for leaks. A central irrigation control system automatically shuts down when it senses a break in a park’s line or control valve. Before the installation of the technology, a line could waste water for hours before being spotted by a park worker or reported by a citizen.

2. Turn off the irrigation system during rainstorms. During storms, irrigation systems in every park can be shut down from a laptop computer. Sometimes the city intentionally runs the irrigation systems in the Indian Bend Wash during a rainstorm. That’s because the irrigation water in the wash comes from its lakes. Operating the irrigation system during a storm prevents the lakes from overflowing and flooding pedestrian paths.

3. Check for spikes in water use. Each month, the city’s irrigation manager receives a water use report from each park. If the park has exceeded its water budget, the irrigation manager follows up with the park supervisor to find out why. The park supervisor is expected to make up for the excess water used during the following months. Park supervisors are evaluated based, in part, on their year-end water-use totals.

4. Don’t overseed in the winter. The city does not plant winter grass in most parks. The Bermuda grass goes brown during the cooler months. It is still alive but dormant. The exceptions are Scottsdale Stadium and Indian School Park used by spring training teams, parts of Civic Center Mall used for community events, and the plaza area of McCormick Railroad Park.

4. Shrink the lawn. The city has converted some grass to drought-tolerant landscape in areas that make sense for the community surrounding the park. To date, Scottsdale has replaced 323,618-square-feet of grass with drought-tolerant gardens.

5. Understand the irrigation system. All park staff members are trained in water management and irrigation maintenance.

Scottsdale measures its success by comparing the water it uses to irrigate its parks to the amount allowed by the Arizona Department of Water Resources. Between 2001 and 2014, the city used 2 billion gallons less than the state allows, a savings to the city of $3.7 million.

Cities offer free workshops for homeowners who need to brush up on irrigation basics. Not the way you want to spend your evening? Hire a landscaper who has completed professional training and certification. A good place to start is with Smartscape professionals.

For 46 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit

Growth And Conservation: Where Do You Draw The Line?

Kathleen Ferris

During the last few decades, cities in the Phoenix Metropolitan area became bustling economic centers providing jobs and homes for millions of new residents. Development spread across what had been farmland, orchards, and virgin desert.

Despite enthusiastic development, city officials worked to preserve open spaces, distinctive desert trees and plants, and water supplies. It was never an easy balance and cities learned to become very practical conservationists. For example, here is a brief description of three conservation ordinances adopted by the City of Scottsdale.

  • Environmentally Sensitive Lands Ordinance: Scottsdale first adopted the ordinance in 1991. It helps to shape the location and size of development in about two-thirds of the city. The ordinance preserves natural landmarks, native plants, archaeological sites and geological sites throughout the city. It applies to private development and development by the city. (Scottsdale has protected most of the McDowell Mountains from development by creating the
    Photos:  Carol Ward-Morris

    Carol Ward-Morris

    30,200-acre McDowell Mountain Sonoran Preserve.) The ordinance protects washes thick with mature desert vegetation to help maintain continuous and connected open space and habitat for wildlife. It limits the number, density and height of buildings and requires developers to set aside open space where the desert is undisturbed or restored to it natural condition. The ordinance not only encourages development that blends with the desert, it also minimizes the city’s cost of building infrastructures, such as roads and water and sewer systems, and reduces the amount of landscape that can be irrigated.

  • Native Plants Ordinance: Scottsdale first adopted the ordinance in 1981. It requires developers (including the city) to salvage or protect 15 types of mature and healthy desert trees, including Desert Willows and Ironwood, and five types of cactus that have reached at least 3-feet in height, including Saguaros and Desert Night-Blooming Cereus. This ordinance applies to city developments, too. To build Appaloosa Library, on Scottsdale Road just south of E. Pinnacle Peak Road, the City of Scottsdale salvaged and replanted 30 desert trees, including 16 Blue Palo Verdes. The purpose of the ordinance is to save slow growing, hard-SONY DSCto-replace plants found only in the Sonoran Desert. Scottsdale has issued over 8,000 native plant permits and salvaged an estimated 350,000 protected plants.
  • Water Conservation Ordinance: Scottsdale first adopted the ordinance in early 1990s. It encourages developers to use low-water technology, appliances, fixtures, water features and landscaping. For example, it limits the size and type of outdoor water features, requiring equipment that minimizes leaks and overspray, such as re-circulating pumps and wind shut-off valves. The ordinance also offers businesses and residents rebates on their water bills in exchange for saving water, such as installing water efficient toilets, SONY DSCremoving turf, and upgrading irrigation controllers. The ordinance limits the amount of grass used in landscape designs, including for schools and churches, commercial buildings, and common spaces in HOAs.

The cities have led in smart development strategies, but their work is never over. While some environmentalists say cities are not doing enough, some developers continue to work against the cities’ efforts to conserve.

Here’s a recent example: During the last session of the Arizona Legislature a bill (HB2570) was introduced that would strip cities of their power to require developers to save some native trees and plants and to require drought tolerant landscaping. While this is hard to imagine, particularly after 15 years of drought, the bill initially met with little resistance and is expected to reappear next year.

As the drought continues, wise water use in our desert environment becomes even more critical. All of us must do our part, including the development community. Stripping cities of important water management tools is counter-productive and just plain wrong.

For 45 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit