Experts discuss government policies that help or hinder water conservation in the built environment, the role of water availability and consumption data in raising awareness and shaping behavior, strategies that developers should employ to reduce the waste of water, and other factors influencing water use.
What are good strategies that state and/or municipal governments can implement to encourage water conservation?
Fred Merrill: Some local governments have differential pricing. The water authority knows how much you should use in your house, without being too wasteful, and they’ll give you a good deal on that amount of water, but as you start to use more than that, the price per gallon goes way up. People really pay attention to their monthly water bill. In hot weather, during the day, when you shouldn’t be watering your lawn, the water authority might charge businesses and residents a higher rate for water use to encourage people to water the lawn in the evenings and at night, when the water has a chance to soak in. If you’re in a water-restricted area—say, the Southwest—you might not even be allowed to water your lawn. In some cases, water companies will actually pay homeowners and businesses to rip up lawns and replace them with xeriscapes, which require minimal water. Also, in a lot of cities and towns, the municipal pipes that move water through the system are so leaky that sometimes 20 to 30 percent of [it] never makes it out to the consumers. So cities are doing a lot of work to find those leaks and stop them.
Rick Carter: At the municipal scale, it is best to take a holistic approach that integrates efficient water supply systems with demand-side conservation techniques and effective stormwater and wastewater practices. In Minnesota, we have a program called GreenStep Cities. There are 29 best practices that cities can follow to become a GreenStep City, and they range from energy-efficiency initiatives to measures for investing in better transportation systems to water-related actions such as demand-side conservation. GreenStep Cities is designed for cities that want to improve their environmental footprint, especially smaller cities that don’t necessarily have the resources themselves to create a plan of action. There are similar programs in other states that provide assistance and recognition.
Laura Bonich: California is leading the way. [It] has passed two landmark pieces of legislation in the past couple of years. The new green building code, CALGreen, limits what kind of plumbing fixtures can be put in homes in new developments. So instead of a 2.5-gallon-per-minute (9 liters) showerhead, for example, you’re only allowed a two-gallon-per-minute (8 liters) showerhead. As a result, all new development in California is using 50 percent of the water used by homes built before the legislation took effect. Another piece of legislation, which takes effect in 2017, will require that every time a home built before 1994 is sold, the indoor fixtures will have to be retrofitted to meet the CALGreen code. So our existing water infrastructure is going to be able to serve more new development than ever.
How do regulations and policies sometimes get in the way of water conservation?
Byron Stigge: When it comes to agricultural uses of water, the opportunities for savings are enormous. But most states in the West have water rights laws that are based on how long you have had the rights to use the water. And if you don’t use the water that you have allocated to your agricultural or industrial use, your allocation is reduced. So this incentivizes consumption of water regardless of the water supply. In regard to the built environment, my firm does a lot of work in developing countries like Mexico, India, and [those in] Africa. In these places, it is common practice to use recycled water, both from rainwater and treated wastewater. Singapore is even mixing small amounts of recycled water into its drinking water supply. The regulatory environment in the United States is not as open to these kinds of solutions. But for regions beginning to experience severe drought, these regulations may need to be rethought.
CARTER: Too many policies and laws actually encourage more water consumption. For example, until not that long ago, waterless urinals were not legal in Minnesota. This year, the state finally adopted a plumbing code that regulates rainwater harvesting for indoor use, but outdoor reuse for irrigation is still unregulated. Without clear and effective guidelines for proven systems, designers, building owners, and code officials struggle with effectively implementing them in projects. Also, some cities have rules for the built environment that require landscaping of a kind that can’t thrive without a significant amount of irrigation. That means the law is essentially requiring people to use more water than they should be.
Bonich: In the last five years, the technologies available for understanding how much water cities consume have gotten much better. But municipal and state governments haven’t necessarily taken into account the effect that conservation technologies have had on water use. A lot of the infrastructure that’s being designed and the master planning being done relies on ten years of historical water use data as an indicator of how much water a new development will use. But that’s not a good indicator anymore, because so much has changed in the last few years. So a lot of municipalities are still overplanning their future infrastructure requirements. We need to shift the investment in infrastructure. If we can build smaller potable water and wastewater systems, and instead spend those dollars building reclaimed water systems, that would make a big difference.
What are the best ways to use data about availability and use of water to encourage conservation?
Carter: To track the progress of cities involved in the GreenStep Cities program, we started the Regional Indicators Initiative in Minnesota. We gather data about energy, water, vehicle miles traveled, and waste. Then we analyze it and present it in a way that people can grasp. The way we present the data on the Regional Indicators website graphically shows the consumption of water and other resources. We’ve found that makes the biggest difference. You can look at spreadsheets all day long, but it doesn’t sink in until you see a bar chart showing that your city’s water use is two times higher than [that of] all the rest of them. We separate water data by residential and commercial/industrial uses so we can analyze trends, and that makes a real difference, too. It’s one thing to look at the total water consumption in a city and try and normalize it, and another to show what’s actually coming out of the tap per household or per capita.
Merrill: Most states have regulations based on engineering standards that estimate how many gallons of water per day will be used by a residential, commercial, or industrial development. For example, in Massachusetts, if you’re building a single-family home, the number is 110 gallons (416 liters) per bedroom per day. So if you have a three-bedroom house, they would estimate that your house might use 330 gallons (1,250 liters) of water per day. For commercial uses, when they’re doing the planning of new facilities, the proponent of the project uses similar standards to estimate how much water will be used daily. Project proponents can then go to the water authority and say, “We think we need X number of gallons a day” for the project. However, the new reality is that regulatory standards are often very conservative, and due to peak demand pricing and emerging water-saving and metering techniques that improve measuring of the time and volume of water use, homes and businesses are often using less water than they used to and lower levels than the standards estimate.
Stigge: Most states and regions in drought-prone areas have a tiered regulatory process whereby they grade the current level of drought, from no drought condition to severe drought. Depending on the level of drought, different degrees of water conservation are required. The key thing is to disseminate that information to the public as clearly as possible, but only as necessary. Just understanding groundwater-level aquifer depletion, or understanding the level of the reservoirs, can have a big impact on people’s water use when these levels are low. For example, Georgia was in a very severe drought situation some years ago, and in that case it made sense to encourage people to take shorter showers and limit lawn watering. But you don’t need to be hammering people about taking shorter showers in New York state, where the water supply is plentiful. There’s no one-size-fits-all approach. The best use of data responds to a region’s climate and varies over time, considering the season’s drought condition.
What water-saving strategies should individual private developers be embracing more?
Bonich: Because the amount of water infrastructure required for new development is often based on out-of-date historical data, the costs to build that infrastructure are higher than they need to be. Residual land value can be driven way down by infrastructure costs. If your new building will use only half as much water as the same building constructed ten years ago, the sewer pipe and the water pipe could be half as big. Developers could be more proactive and ask their design teams, “Is that the infrastructure we really need, or is that just the infrastructure [called for by] the city code created 40 years ago?” But time is money, and it would take a lot of time and effort for a developer to go to the city and ask the city to change those standards.
Merrill: For an urban developer constructing a high-rise or mixed-use building, installing highly efficient plumbing fixtures that meet LEED [the U.S. Green Building Council’s Leadership in Energy and Environmental Design rating system] standards is probably the most important strategy. For a developer of a master-planned community, not only are the fixtures important, but also the policies that govern how homeowners can use water for their lawns and how water is disposed of after use. Many master-planned communities will now use treated wastewater and recaptured rainwater for irrigation.
Carter: [Private developers should embrace low-maintenance] drought-tolerant native landscapes that incorporate stormwater best management practices. In the Twin Cities, nearly one quarter of our drinking water is used for irrigation. Developers should embrace landscapes that conserve potable water by reducing irrigation requirements, protect drinking water sources from pollution associated with stormwater runoff, replenish groundwater through infiltration, and create a beautiful public realm that increases property values. Because they capture stormwater, these landscapes can drastically reduce irrigation costs and stormwater fees.
Stigge: The best developers I work with are very attuned to their customers, their climate, their region, and their local political situation. When you’re attuned to your climate, you naturally select plantings that require minimal watering, and you naturally select from the wide range of low-flow fixtures that are available. To my mind, the biggest savings are possible with discretionary water use in the landscaping. I work with developers in places like India and Africa, where projects require on-site wastewater treatment. And most projects in India are required by law to incorporate rainwater harvesting. So in a way, some developing countries are forced to be on the cutting edge because of the limitations of their cities’ sewer systems and drinking water networks. In the United States, the best projects have a responsible landscape plan that has the appropriate amount of irrigation.
What other issues related to water should more people know about?
Bonich: Electricity and natural gas are regulated by the federal government, but water and sewer systems are regulated locally. So I might convince a water district to adopt the right conservation standards and to project future water use based on the assumption that new homes really are going to use less water. But then in the next town, I have to start all over explaining these issues to the water district there. It would be great if we could get federal legislation that requires ultra-low-flow fixtures or limits outdoor landscape irrigation, but water is regulated by local municipal ordinance.
Stigge: I’ve studied water systems extensively around the world, and my assessment is that the use of potable water in buildings can be reduced by about 20 or 30 percent just by using water-saving technologies. But the total amount of water used for human activities in buildings, like drinking, bathing, and washing, is relatively small. We actually eat more water than we drink: according to the U.S. Department of Agriculture, nearly 80 percent of water is used for agricultural uses across the United States. So to really conserve water, we have to address the agricultural sector.
Merrill: Many metropolitan water authorities are serving more people with less water than they ever have, because of all the water-saving technologies and strategies now available. If everybody in a community or region had low-flow toilets and low-flow showerheads, that would greatly reduce water consumption. The biggest impact comes from many people making a small change.
Ron Nyren is a freelance architecture and urban planning writer based in the San Francisco Bay area.