It's time to reconsider cisterns

The looming water supply problems in this part of Florida have revived some talk of an old idea: cisterns.

Cisterns have been used in various parts of the world for centuries.

In case you’re unfamiliar with cisterns, they are simply water-tight containers of various sizes that are used to collect and store rainwater for future use.

The concept was part of a discussion at the recent Polk County Water School that I attended to give local government officials and some other invited folks a chance to hear the latest about local water issues and solutions.

In the current terminology, cisterns could be viewed as another alternative water supply.

You may hear this term regularly if you’re following local water supply issues because the best research has determined that tapping the Floridan aquifer to supply all of our water needs is coming to an end.

That’s because continuing to pump increased quantities of water from the aquifer at the rate we have done in the past is unsustainable.

That’s where alternative water supplies come in.

This word about the approaching end of business-as-usual in the water supply world is coming out at the same time as a series of in-depth studies conducted in conjunction with a regional effort called the Central Florida Water Initiative. This initiative grew out of an earlier effort to forge a regional plan for supplying water and heading off the kind of water wars that raged in the Tampa Bay area in the 1970s and 1980s.

If you want to know the effect of unsustainable water pumping, the Tampa Bay area offers plenty of lessons.

I recently received a 2010 report to the Florida Legislature from the Southwest Florida Water Management District that contained a map depicting a 50-year boundary for salt-water intrusion in the Floridan aquifer that extends to the outskirts of Brandon. It leaves you to wonder how close to Polk County the 100-year boundary will be.

Getting back to cisterns, they can be used easily for any use except drinking or cooking, but that covers most water that is used by most homes or businesses.

I dug out a 30-year-old Swiftmud report on cisterns from the pile of reports I collect on the off chance I might need to refer to them again some day.

The report gave a mixed message on this topic and concentrated on the use of cisterns in coastal counties where water supplies are under the most strain.

The report concluded that if only 5 percent of homes in coastal areas installed a 2,000-gallon cistern, they could save 11.1 million gallons a day that would otherwise come from conventional sources. Most of that water would be used for lawn irrigation, for those of you who are still doing that sort of thing.

Interestingly, that figure totals about a quarter of the projected water deficit Polk utilities face by 2035.

However, the report also points out that at the time there were more cost-effective means of promoting water conservation and would require sizeable financial incentives to encourage residential or commercial water customers to install cisterns.

As a practical matter, the report concludes the most likely reason anyone would use a cistern is in cases where water supplies are limited or unsuitable.

That could change if water rates increase in the future as utilities look to cover the cost of pursuing expensive alternative water supply projects such as tapping brackish sections of the aquifer and engineering and constructing extensive water transmission lines.

In the meantime, there are ways to experiment with this concept on a smaller scale, such as purchasing a rain barrel or two and collecting rainwater from storm gutters.

And, there are ways to reduce your irrigation demand by installing native plants or other species that can adapt to Florida’s soils and weather in your landscape, and replacing turf with flower beds or less thirsty ground covers.

The way we deal with water is beginning to change in major ways. Get ready for it.

Panama birding talk

Linda Van Deman and Gail French will present a program on birdwatching in Panama at the next meeting of Ridge Audubon Society at 7 p.m. Tuesday at the Audubon center in Babson Park. The meeting is open to the public and will be preceded by a cover-dish supper at 6 p.m.

The center is located at 200 N. Crooked Lake Drive.

Bird of prey talk

Laura VonMutuis, education manager at the Audubon Center for Birds of Prey in Maitland, will be the guest speaker at the next meeting of Ancient Islands Sierra at 7 p.m. Thursday at Circle B Bar Reserve. She will be accompanied by some of the birds that live at the center.

The meeting is free and open to the public.

Follow Tom Palmer's environmental musings at www.lakebluescrub.blogspot.com