Printer Friendly

Water tight.

Four cities' innovative conservation efforts prove that saving water makes economic and environmental sense.

Mexico City's historic plaza offers a strange sight. The imposing Metropolitan Cathedral, built soon after the 16th-century Spanish conquest, droops rather dramatically on its right side, and slightly less so on the left. Inside, an array of tension wires and green metallic beams support the weakening edifice. The capital's revered cathedral is sinking, and it has little to do with the engineering skills of the early Spaniards. Large parcels of land are slumping as the city siphons its underground water supply, and the resulting structural damage is just the most visible of many consequences.

Mexico City is an extreme case, but there are many cities around the world that have overstepped the limits of their water supply. Homes, apartments, offices, stores, restaurants, and government buildings account for less than a tenth of all the water used in the world today - the remainder goes to farmers and industries - but their demands are concentrated in relatively small geographic areas. And, in many cases, those demands are escalating. As cities expand, they strain the capacity of local water supplies and force engineers to reach out to ever more distant sources.

Beyond the challenge of finding enough water, it costs a lot to build and maintain the reservoirs, canals, pumping stations, pipes, sewers, and treatment plants that make up modern water and wastewater systems. Collecting and treating water and wastewater also takes a great deal of energy and chemicals, adding to environmental pollution and the operating costs of a community's water system. Under this financial strain, many cities are having difficulty meeting the water needs of their residents, and many low-income residents in developing countries get no service at all.

Conservation, once viewed as just an emergency response to drought, has been transformed in recent years into a sophisticated package of measures that offers one of the most cost-effective and environmentally sound ways of balancing urban water budgets. Just as energy planners have discovered that it is often cheaper to save energy up front - for instance, by investing in home insulation and compact fluorescent lights - than to build more power plants, water planners are realizing that water efficiency measures can yield permanent water savings and thereby delay or avert the need for expensive new dams and reservoirs, groundwater wells, and treatment plants.

Slowly the idea is catching on that managing demand rather than continuously striving to meet it is a surer path to a secure water supply - and will save money and protect the environment at the same time.

Water Balance

Many urban areas simply have no feasible way to balance supply and demand without conservation and more efficient water use. Mexico City is a prime example. This sprawling metropolis of 18 million people relies on groundwater for more than 80 percent of its supplies. Pumping exceeds natural replenishment by 50 to 80 percent, which has caused water tables to drop and aquifers - water-holding geologic formations - to compress. This, in turn, has led to sinking of the land and damage to surface structures, including the cathedral.

Mexico City, which sits in a cramped, high mountain bowl, has outstripped its supply of groundwater and is forced to search out water on the other side of the mountains that hem it in. The city now meets 17 percent of its demand by bringing water from the Cutzamala River system 80 miles away and lifting it 3,900 vertical feet - all at enormous cost. With the metropolitan area expanding by more than half a million people each year, officials are racing against time to achieve some degree of water stability.

Faced with such an intractable problem, the Mexican government and city officials are orchestrating an aggressive water conservation effort. In 1989, the federal government took a bold step in adopting a strict set of nationwide efficiency standards for household plumbing fixtures and appliances. These require toilets - the biggest water guzzlers in the home - to use no more than 1.6 gallons of water per flush. Maximum limits have been set for showers, faucets, dishwashers, and washing machines as well.

Mexico City has launched an ambitious program to replace conventional toilets using about 4.2 gallons with the 1.6-gallon models in public places, commercial buildings, and private residences. By late 1991, more than 350,000 toilets had already been upgraded, saving nearly 7.4 billion gallons of water each year - enough to meet the household needs of more than 250,000 residents. Officials also hiked the city's water rates in 1990, while encouraging residents to install a package of low-flow shower heads, toilet dams, faucet aerators, and other home water-saving devices, and to be more thrifty overall. To bolster the whole effort, a large-scale public information campaign - including educating schoolchildren and airing radio and television spots - is under way to raise awareness of the city's water plight and tell people how they can conserve.

It is too early to judge the program's effectiveness, but officials are projecting that water use will fall from the current level of 79 gallons per person per day, to 66 gallons by 1996. Unfortunately, without a slowdown in birthrates and migration to the capital, population growth will negate these savings, and total water use in Mexico City will continue to climb, albeit at a slower pace.

Although not in as dire straits as the Mexican capital, the Canadian city of Waterloo, in Ontario, had similar reasons for shifting from the traditional approach of expanding supplies to managing demand. The Waterloo program has made conservation an effective part of the city's long-term water strategy through raising the price of water, educating the public to the need and ease of conserving water, and distributing water-saving devices to make home plumbing fixtures more efficient. Volunteer groups have distributed retrofit kits - including toilet dams, faucet aerators, and low-flow showerheads - to nearly 50,000 homes, and homeowners have been urged to conserve water outdoors as well. Waterloo's per-capita water use fell 10 percent in just three years.

As in Mexico City, Waterloo's efforts will be bolstered by province-wide efficiency standards for new plumbing fixtures that will take effect in 1993. By 1996, new toilets throughout Ontario must meet the 1.6-gallon standard, the strictest required today. Ontario has also set an ambitious goal of zero growth in water use for the next 20 years, which will be helped along by the conservation initiatives Waterloo already has under way. "If we achieve zero growth, we will reduce stress on the environment, lessen the likelihood of water shortages and reduce energy costs," says Bud Wildman, Ontario's natural resources minister.

Waste Not, Want Not

The only motivation some cities need for conservation is a look at the money they shell out to treat wastewater. In the mid-1980s, the sewage treatment plant in San Jose, California, was nearing capacity, and the city was faced with the prospect of building a new one at a cost of $180 million. The city decided to pursue a different option. Since less water used indoors translates into less wastewater released to the sewer system, the city initiated a large-scale program to reduce residential and industrial water use quickly. Officials hoped to delay the need for this huge capital investment and save the city and its residents money.

San Jose set a goal in 1986 of cutting wastewater flows to the treatment plant by 10 percent by 1996. The centerpiece of the conservation program was a massive retrofit campaign, in this case involving the distribution of water-saving devices door-to-door to some 220,000 households. Diligent canvassers made at least three attempts to talk with residents about the importance of installing the devices. As a result, 90 percent of the targeted households cooperated - an unmatched success rate. Water use in participating homes dropped 10 to 17 percent. When industry conservation was factored in, the program had cut wastewater flows as of 1991 by an estimated 1.4 billion gallons a year, about the amount 20,000 U.S. households would send to a treatment plant.

Low Flow

In the greater Boston metropolitan area, the environmental consequences of expanding the water supply forced local officials to take a hard look at conservation. That soul-searching resulted in one of the most comprehensive and successful water-efficiency programs in the United States. When demand in the metropolitan region rose above the dependable yield of the water supply system in the early 1970s, water planners did what most of their colleagues do - they looked for another river to dam or divert. The Boston engineers proposed diverting some of the flow of the Connecticut and Merrimack rivers eastward by tunnel to the metropolitan area.

Environmental groups asserted that diverting the rivers would contaminate the city's otherwise relatively pure water supply, which did not require filtration, and added that the increased concentration of pollutants resulting from diminished river flows would damage salmon restoration efforts. They organized opposition to the projects in some 48 towns across Massachusetts, which, along with the engineering scheme's high cost, led the city to consider seriously ways to curb water demand instead.

As a result, in March 1987, the Massachusetts Water Resources Authority (MWRA) launched an aggressive strategy of conservation and increased efficiency throughout its service area, which includes some 2.5 million people. Water-saving devices were installed in about 100,000 homes, leaks in old pipes were found and repaired, more than a million pieces of conservation literature were distributed to schoolchildren, and advice on water-saving measures was given to hundreds of businesses and industries.

The results were impressive. Total annual water demand fell from 122 billion gallons in 1987, when the program began, to 102 billion in 1991, a 16-percent drop (see Figure). Boston's water use is now below the system's safe yield. The MWRA plans to install water-saving devices in an additional 330,000 households during the next few years, at no direct cost to the customer, and to extend other aspects of the program as well. The expected savings have prompted MWRA officials to recommend postponing an expansion of the water supply until at least 1995. Moreover, the program has been a bargain, with the conservation measures costing a third to half as much as supply-side options. "For the first time in 20 years, we are living within our means," says Paul Levy, former MWRA executive director.

Water Break

As the experiences of Mexico City, Waterloo, San Jose, and Boston illustrate, conservation makes sense for many reasons, and a different mix of measures may be appropriate in each situation. In almost every case, however, successful efforts to curb domestic water use include some combination of economic incentives, regulations, and public outreach to promote the use of water-saving technologies and behaviors. These measures arc mutually reinforcing, and together they constitute a water supply option as reliable and predictable as a new dam and reservoir. They also are often less expensive and better for the environment.

Raising the price of water to better reflect its true cost is one of the most important steps any city can take to propel conservation efforts. Proper pricing gives consumers an accurate signal of just how costly water use is, and it allows them to change their behavior accordingly. Studies in a number of countries, including Australia, Canada, Israel, and the United States, suggest that household water use drops 3 to 7 percent with a 10-percent increase in water prices.

Water is consistently undervalued, and as a result is chronically overused. Not only do current water prices typically fail to promote efficiecncy, the water rate structures of many utilities actually reward waste by charging less per gallon when more is consumed. Seven out of 10 residents in Manitoba, Canada, for instance, are charged according to this perverse "declining block" pricing policy, as are one out of three in Alberta and Ontario. Amazingly, water charges for most British households are linked to the value of the home, not to actual consumption.

Many residences in industrial and Third World cities are not equipped with water meters, which precludes even the possibility of charging people appropriately for their water use. Metering encourages savings by tying the bill for water to the amount used. The city of Edmonton, Alberta, meters all residential users, and its per-capita water use is half that of Calgary, which is only partially metered. The areas of Calgary that are metered, however, register water use rates much like Edmonton's. Trials in the United Kingdom have shown that metering can cut household use by 10 to 15 percent.

Raising water prices is not a popular political move, but if accompanied by a public outreach campaign that explains the need for a price hike and the steps consumers can take to keep their water bills down, it can be both doable and beneficial. For example, when officials in Tucson, Arizona, were faced with dire water supply conditions in the mid-1970s, they raised water rates sharply to better reflect the true cost of water services. At about the same time, the city ran a public education campaign called "Beat the Peak" with a goal of curbing water use on hot summer afternoons, when there was the greatest danger of demand outrunning supply. The result was a 16-percent drop in per-capita use within a few years, which, along with the lowered peak demand, allowed the Tucson water utility to cut its planned expansion costs by $75 million.

Pricing was the main tool of a conservation strategy adopted by the water utility serving Bogor, Indonesia, as well. With a proposed water protect estimated to cost twice as much per gallon as existing supplies, the utility opted to try reducing demand through more effective pricing. It tripled or quadrupled water prices, depending on the amount used, to encourage households to conserve. Between June 1988 and April 1989, average monthly residential water use dropped nearly 30 percent, enough to allow the utility to connect more households to the urban water system at a lower cost.

Built-In Efficiency

Since economic incentives and public out-reach won't motivate everyone to conserve, water-efficiency standards for common fixtures - toilets, showerheads, and faucets - are a necessary component of a dependable conservation strategy. Standards establish technological norms that ensure a certain level of efficiency is built into new products and services. As already noted, Mexico has established nationwide standards, and Ontario is including standards in its conservation strategy as well.

In the United States, there has been a growing movement at the state level to mandate the use of water-efficient plumbing fixtures. In 1988, Massachusetts became the first state to require that all new toilets installed use no more than 1.6 gallons. Since then, 14 other states have followed suit, most of them adopting efficiency standards for showerheads and faucets as well.

Legislation setting national standards was signed into law in October 1992 as part of a broad energy bill. It requires that showerheads and faucets manufactured in the United States after January 1, 1994, use no more than 2.5 gallons per minute; domestic toilets manufactured after that date are to use no more than 1.6 gallons per flush. As all new homes and major remodeling nationwide incorporate these more-efficient fixtures, average U.S. indoor residential water use should fall gradually from 77 gallons per person a day to 54 gallons, a 30-percent reduction, according to estimates by Boston-based water conservation consultant Amy Vickers.

Effective pricing, regulations, and public outreach can also help curb the use of water outdoors. In many dry regions, lawn sprinkling accounts for anywhere from a third to half of residential water demand. This water has a particularly high economic and environmental price, since it is used most during hot summer days when utilities experience their highest level of use. Meeting this peak demand requires planners to develop more water sources and treatment capacity than is typically needed during the rest of the year.

Many U.S. communities have turned to "xeriscape landscaping" on public and private land in recent years to save water. From the Greek word xeros, meaning dry, xeriscape designs draw on a wide variety of attractive indigenous and drought-tolerant plants, shrubs, and ground cover to replace the thirsty green lawns found in most suburbs. A study in Novato, California, found that xeriscape landscaping cut water use by 54 percent, fertilizer use by 61 percent, and herbicide use by 22 percent.

Just a decade old, the xeriscape concept has spread rapidly through parts of the United States. Programs in at least eight states - including several in the more humid East - actively support this form of landscaping as a way to conserve water and improve the urban environment. Tucson, Arizona, gave the approach a boost in early 1991 by forbidding new developments from having more than 10 percent of their landscape area planted in grass. Xeriscape landscaping is making inroads in a handful of other countries, including Australia, Canada, and Mexico.

Patching Leaks

Water conservation can't ignore waste at the source - leaks in the water distribution system itself. Finding and repairing leaks usually yields a big payoff, especially in older cities. As urban water systems deteriorate because of age or lax maintenance, a lot of water can be lost through broken pipes and faults in the distribution network. More than half the urban water supply in Cairo, Jakarta, Lagos, Lima, and Mexico City simply disappears. Although some of this water is probably siphoned off by poor residents not served by the system, much of it is wasted. This makes for big financial losses since cities still pay to have this unaccounted-for water collected, stored, treated, and distributed, even though it never reaches a billable customer.

In most cases, finding and fixing leaks rewards a city not only with water savings, but with a quick payback on its investment as well. At a cost of $2.1 million, the Massachusetts Water Resources Authority's leak detection program cut system-wide demand in greater Boston by about 10 percent, making it one of the most cost-effective measures in the city's conservation strategy. Leak detection and repair can be especially beneficial in Third World cities that suffer extremely large losses. If Jakarta, Indonesia, could cut its unaccounted-for water from 51 percent to 31 percent of output, for example, it could save 11.9 billion gallons annually - enough to supply 800,000 people.

With some notable exceptions, such as Mexico City and Bogor, Indonesia, few Third World cities are trying to conserve water. Most are preoccupied with the daunting challenge of providing reliable water services to the large number of people now lacking them. Since average household use in most developing countries is a fraction of that in industrial countries, conservation and efficiency are often viewed as irrelevant or, at best, as options to pursue later.

But, in fact, conservation is an integral part of any practical solution to poorer nations' water supply problems. The Third World's population is growing by 90 million each year, and widespread migration from rural areas to cities guarantees explosive urban growth. Water-efficient plumbing, pricing policies, and other measures offer these cities an opportunity to build conservation into their water plans early on, allowing more needs to be met with fewer resources and curbing water costs overall.

It would be a costly mistake for the developing world to adopt the water-intensive ways of industrial countries, many of which find their water practices unsustainable. It costs between $450 and $700 per resident to build water distribution networks, connect each individual household to water and sewer pipes, and construct centralized water and wastewater treatment plants. Efficient plumbing fixtures and other conservation measures can help shrink these costs by lowering each household's water demand. They allow cities to scale down the size of expensive new treatment plants and distribution pipes, cutting both capital and operating expenditures.

There are signs that the idea of incorporating conservation into developing countries' long-term water supply planning may be catching on. The World Bank and the United Nations Development Program have started working with a number of countries - including Chile, China, India, and South Korea - to identify cities that could serve as good demonstration sites for urban water conservation.

In rich and poor countries alike, conservation and efficiency are the wave of the future in meeting urban water needs in a cost-effective and environmentally sound manner. Astute entrepreneurs with new conservation technologies and services already are finding new markets to pursue. And efficiency measures show clearly how economic gains and environmental protection can go hand-in-hand. Conservation's potential is vast - and it has barely been tapped.
COPYRIGHT 1993 Worldwatch Institute
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1993, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:water conservation
Author:Postel, Sandra
Publication:World Watch
Date:Jan 1, 1993
Previous Article:Breaking away.
Next Article:Will Clinton give industry a green edge?

Related Articles
America's waters: a new era of sustainability; report of the Long's Peak Working Group on National Water Policy.
New conservation efforts help recapture huge water costs.
Booklet on Water Conservation Fixtures and Flow Reduction Design.
Environment, Health and Safety (EHS) regulatory alert. (Legal Ease). (National Water Commission's water conservation standards, Mexico).

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters