Mid-Florida's environment: is it sinking?

Bill Partington doesn't want you to come to Orlando. As director of the Florida Environental Information Center in adjacent Winter Park, he has issued a mock ''pass'' allowing tourists and newcomers to leave Florida at the nearest border without paying a toll.

And he has published a 1982 ''Florida Calamity Calendar'' that highlights both natural and man-made disasters that have befallen the state since the landing of the first tourist, Ponce de Leon.

He and other central Florida environmentalists have formed a group they call the Florida League Against 'Progress.' Its credo: ''Never say anything nice about Florida when in the presence of someone who might come here.''

What concerns environmentalists the most about Orlando's rapid growth is water -- both the availability of a fresh supply and the disposal of it once it has been used.

During a severe drought last spring, a woman standing near her home in Winter Park was shocked to see a large tree in her yard begin to sink into the earth. Within hours, her home, all her property, a nearby municipal swimming pool, parts of two city streets, and several Porsches waiting to be fixed at a mechanic's shop had all disappeared into a yawning sinkhole.

The sinkhole has become a tourist attraction itself, but environmentalists say it is a warning of what could happen throughout much of central Florida if growth is unchecked and increasing amounts of water are pumped out of the ground.

''Water is a limiting factor for Orlando's growth,'' said veteran hydrologist Gerald Parker. ''You're going to see more and more sinkholes, and the cost of pumping water out of the ground is going to increase.''

Orlando sits on a sea of fresh water embedded in limestone rock formations known as the Floridian aquifer. The only source of new fresh water to recharge that aquifer is rainfall.

During the past 20 years the amount of rain falling on Orlando has been well below normal. At the same time, the amount of water pumped out for residential, industrial, and agricultural use has been steadily increasing.

With more development, environmentalists say, vast areas of land that used to absorb rainwater have been covered with asphalt, cement, and roofs. Rain is evaporating, rather than seeping into the ground, they say, and large amounts of water are being channeled away through drainage systems.

As a result, Mr. Parker said, the level of water in that aquifer has been dropping. Sinkholes develop when water no longer supports a clay layer on top of a cavern in the limestone aquifer.

But sinkholes are just a dramatic symptom of larger environmental damage caused by the dropping water level, he said. Florida's swamplike environment is based on the groundwater level being at or near the surface. If it drops permanently, the ecosystem will change, he said.

''Many swamps and lakes will dry out,'' he said, ''and the opportunity for forest and muck fires will increase. Animals, birds, and plants that require swampland cannot live. It's not just people who are harmed by over-pumpage and over-drainage, but the whole environment.''

Some environmentalists warn that if the soil dries out, Florida could become a desert.

Sonny Vegara believes the environmentalists are exaggerating the problem. He is director of the St. Johns Water Management District which is reponsible for assuring that the Orlando area has an adequate water supply.

''Water is not a limitation on Orlando's growth as long as there is a proper concern with the resources that are available,'' he said. ''As long as we continue to have drought conditions, the likelihood of sinkholes increases. And certainly the use of water in the area is going up. But Orlando sits on a tremendous resource.''

The danger, he said, is in not protecting it.

Some waste water in Orlando is still injected into wells down into the aquifer, he said, where it mixes with the same water that is being pumped up for public supply.

Ditches to drain storm water runoff are so efficient, he said, that they circumvent the natural cleansing powers of marshlands and dump polluted water down sinkholes or into injection wells.