By Mary Ann Dickinson
The world is watching with sympathetic alarm as Cape Town’s water crisis deepens.
As of 1 February 2018, fewer than 100 days of water remain to serve a growing metropolitan population of 4.3 million. The shortage, largely due to rapid population increases of 79 percent in only 23 years, hints at future urban shortages looming from Tehran to São Paolo to Bangalore, all experiencing the same phenomenal growth and thus also facing the prospect of running out of water within a frighteningly short timeframe.
What should they do? During past water crises, city leaders typically beg their citizens to conserve water, anticipating that they will very soon have to take more drastic steps, such as rationing access or even outright shutoff. As the city falls deeper into water deficit, it concurrently races to increase supplies as quickly as possible, rushing through contracts for dams, diversions, wellfields and desalination plants to match the burgeoning demand. But in reality the timetable for developing meaningful new supply can take decades, not months.
There is, however, a third way: investing in water efficiency.
A water utility’s direct investments–installing water efficient plumbing, appliances, equipment and demand-side programmes–can yield tangible results. Every cubic metre of ‘old water savings’ translates into a unit’s ‘new water supplies’ that can be delivered immediately to city residents impacted by shortages. The soft and light efficiency investments also make the city’s long-term delivery system more resilient, at a far lower cost, than building heavy new supply-side infrastructure.
This ‘third way’ buys time, as Cape Town can learn from a place that already ran out of water. Nestled between two mountains southwest of Chattanooga, Tennessee, the tiny town of Orme was once a humming coal-mining community. In 2007, its well ran dry, with no other water supply available. The emergency response was to bring in water in a fire truck from a neighbouring town; that provided Orme’s residents with water for three hours a day. In 2008, volunteers from the plumbing industry replaced all the old fixtures in the town, installing in every home and business new water efficient toilets, showerheads, and taps. These efforts successfully quadrupled the meagre three-hour-per-day supply to twelve.
To be sure, Orme is a small town that offers a simple example. Yet metre for metre its proven solution can be quickly replicated and scaled up for much larger cities. Water saved through plumbing retrofits can then be made available to other residents to ease the shortage. Properly financed, water efficiency programmes can save a considerable amount of water, equalling or even surpassing over time the amount of water filling a newly constructed reservoir. But the important point is this: on the basis of cubic metres gained, water efficiency programme investments are much cleaner, cheaper, faster and fairer than building new supplies.
Australia learned this lesson during its 10-year Millennium Drought. Building new dams would have cost US$1,370 per Megaliter (/Ml) of water delivered. By contrast, the same Ml could be added by plugging leaks in the network at a cost of only US$365/ Ml and the country gained additional supplies by replacing high flow plumbing fixtures for just US$454/ Ml, less than a third of the cost of developing new supply.
Los Angeles has reaped even higher gains from water efficiency. The most affordable desalination plant would have cost the city US$1,216/Ml so the city turned to direct investments in water efficiency retrofit programmes that cost as little as US$41/Ml, less than 4 percent of the cost of the desalination plant compared per Ml. Even recycled water can be produced and delivered in Los Angeles for as little as US$487/Ml.
Money matters most for tight urban budgets. Yet beyond cost savings, and averting a catastrophic shortage crisis, water efficiency investments also provide long-term energy savings and spur economic development. A recent Alliance for Water Efficiency study found that direct national investments in water efficiency programmes can generate economic benefits up to 2.8 times the value of the original direct investments and boost Gross Domestic Product up to 1.5 times the original investments. They also generate demand for skilled labour, creating 12,000-26,000 jobs for every US$1 billion invested–a politically popular outcome that helps ease the transition.
Water efficiency can also minimise a rise in the water tariff that would otherwise have risen to cover expensive new supply and treatment capacity. Studies show that tariffs are lower when long-term water conservation programmes have been implemented that keep demand level even as population increases. A report in Westminster, Colorado documents that their tariff would have been nearly twice as high if 25 years of water efficiency investments had not been made to avoid these more expensive capacity increases.
Investing in efficiency makes sense for any water utility struggling with growing consumer demand, preferably before the shortage starts. But even during a crisis, cities can implement efficiency programmes much faster than constructing new reservoir supply, at lower cost, and with greater resiliency.
As reservoirs empty and aquifers dwindle, it is painful enough–and rarely successful–to ask consumers to voluntarily change behaviour overnight. A truly successful utility will match customer outreach with direct utility investments using fixtures, which are as efficient as possible.
