Rain on the Roof
The island has been settled since the early 1600s, so Bermudians have had some experience dealing with drinking-water problems. What’s evolved there today is an interesting mix of low- and higher-tech with a possible lesson or two for Florida.
With no available groundwater, Bermudians have had few alternatives for most of the past 400 years aside from capturing and storing rainwater. And homes are engineered to that end: Every Bermudian house has its own cistern somewhere beneath it. (The law prohibits building a bathroom or kitchen above the cistern.) Meanwhile, the tiered, whitewashed-limestone roofs that are one of the island’s trademarks are built to feed the cisterns — roofs are supposed to collect 80% of the water that falls on them. The tiers keep the rain from blowing off the roof, and special paint or traditional lime wash help clean the water. A long gutter built diagonally across the lower tiers channels the water into downspouts, which filter it and send it into the cistern. Chlorine is added periodically to keep the water sanitary. A pump moves the water, when needed, back up from the cistern into a pressurized tank and from there into showers, faucets and toilets in the home.
As long as roofs and cisterns are cleaned and maintained, the system seems to work pretty well — in any event, Bermudians aren’t keeling over in droves from water-borne illness. I drank the tap water that came from the cistern underneath the apartment building where I stayed without hesitating beforehand or regretting it afterward.
With growth — at more than 3,370 people per square mile, Bermuda is among the most densely populated places on Earth — the island has had to develop additional sources of water. One discovery: As rainwater percolates down through the island’s limestone base it creates bodies of brackish water with “lenses’’ of fresh water at the top. The government pumps the lens water and sells it to private businesses. When residents’ cisterns run low, they can order water delivered via tanker truck to their cistern.
A few very small-scale desalination plants have been built in recent years, but 90% of residents’ potable water still comes from rainwater, lens water — and imported bottled water.
I didn’t come back from Bermuda thinking that cisterns are any kind of be-all answer to Florida’s water problems, but my time there did make me think about how solutions to problems tend to get defined in terms of the technology of the era when the problem is perceived. So when Bermuda settlers 400 years ago found they needed to store rainwater to survive, they built barrels and dug holes in the ground. Their system has evolved to include more modern ways to boost supply.
Florida, faced with water problems in a modern era, has turned — almost exclusively — to modern, high-tech, mass-scale pumping and piping. And we continue to look to ever more complicated and expensive technical solutions to our water problems — witness the desal plant in Tampa Bay.
Much less money and effort, unfortunately, is going into consideration of lower-tech approaches oriented toward using less rather than producing more.
Cisterns, for example, are not allowed at all as a source of drinking water in Florida, and many communities don’t even allow them as storage for irrigation water. (About half of Florida’s water supply goes to water lawns, water managers estimate.) In the wake of the 2001 drought, the state Department of Environmental Protection issued a report that basically dismissed cisterns as sources of either potable or non-potable water. “It is difficult to make and site a large enough cistern to meet most single-family residential irrigation demands, and many deed restrictions do not allow aboveground vessels,” the report concluded. Interesting conclusions in a state that has no problems in making, siting or permitting many thousands of the topless cisterns we know as swimming pools.
DEP report notwithstanding, a few notable examples of cisterns have emerged around Florida. Two 2,500-gallon models at the Florida House Learning Center in Sarasota store water for irrigation and toilet-flushing. The home is a demonstration project for sustainable development practices. Meanwhile, the University of Florida’s Rinker Hall has an 8,000-gallon cistern that captures rainwater for irrigation and toilets. The building serves about 1,000 students and faculty a day, using less potable water than the average home. Cisterns are also part of a UF research program in Hastings; homes there will capture runoff in cisterns and use the water for irrigation.
The point here is not to beat the drum for cisterns. Rather, it’s that conservation is becoming increasingly elemental to successful growth — and that successful strategies can embrace older strategies along with the best and brightest current ideas and technology. Plenty of wise businesspeople understand this already. Duke Power CEO Jim Rogers has made conservation and efficiency somewhat of a cause recently, advocating an incentive structure that encourages utilities to create capacity through conservation. “We think that the most environmentally benign plant you can build is the one you don’t build,” he told New York Times columnist Tom Friedman recently.
In the context of water and Florida, it will certainly remain true that the cheapest water always will come free out of the sky rather than from a water management district’s well or desal plant. Whether we drink it or not, it seems wise to be open to ways that would take more advantage of that resource.