Florida's local governments are at a crossroads, and their next steps will have enormous environmental and financial implications. Ready or not, most cities and counties will face mandatory reductions in pollutants to meet total maximum daily loads being established by the state and EPA for impaired rivers, lakes, estuaries and coastal water bodies.

Worse yet, those reductions will be difficult to achieve with existing surface water regulations and treatment approaches. In basins draining to surface waters, current water management district rules typically regulate peak runoff from a site-the rate of discharge-rather than volume. This has resulted in a net cumulative increase in the volume of stormwater runoff from developed lands.

At the same time, research indicates that while conventional stormwater detention ponds are effective in removing total suspended solids, they are not as effective in removing contaminants of concern such as nitrogen and phosphorus-which will probably be further limited by TMDLs.

On average, about one third of nitrogen and two thirds of phosphorous is captured. The bottom line-more runoff and more pollutants in the runoff-will leave communities scrambling to make costly stormwater treatment improvements that could run into the tens of millions of dollars to implement.

With 1,000 new residents pouring into Florida every day, changing the way we develop land becomes essential. Given that stormwater treatment already demands a significant portion of public and private development expenditures, local governments will have to adopt less intensive and more efficient land development practices just to hold the line on pollution from new growth.

Low impact development has emerged as a highly effective and attractive approach to controlling stormwater pollution in already urbanized communities and watersheds undergoing development. Its goal is to preserve as much of a site's natural integrity and pre-development hydrology as possible and reduce pollution by treating stormwater closer to where it falls rather than piping it to a centralized pond.

At its core, LID also treats water as a resource to be retained and reused wherever possible, rather than being discarded. When incorporated in a systematic way, LID tools and techniques can enhance the local environment while saving developers and local governments money.

Common practices include:

* Less impervious cover as a result of preserving more of a site's natural features

* Planted bio-retention areas in parking lot islands, at the edge of paved areas, and at the base of buildings to filter stormwater pollutants

* Permeable paving materials that allow rainwater to percolate into the ground, such as pervious concrete or vegetated pavers

* Vegetated rooftop gardens or "green roofs" that capture rainwater and reduce indoor energy bills by adding insulation

* Cisterns or rain barrels that capture rainwater for reuse

* Native or drought-tolerant landscaping and drip irrigation

* Soil amendments to increase absorption and pollutant removal

* Vegetated swales and buffers, and trees to absorb water and provide shade

*Pollution prevention and good housekeeping.

LID costs less than traditional stormwater management systems to build and maintain, in part because it requires fewer pipes and in-ground infrastructure. But its benefits don't stop there. The associated vegetation also enhances aesthetics and property values, improves wildlife habitat and decreases flooding as a result of less impervious surface area.

A number of communities already are leading the way. Sarasota County has developed model "green building" ordinances that provide incentives to developers who meet more stringent environmental design standards in construction and site development. More and more developers are seeing the marketability of their projects increase as they incorporate environmentally sensitive building materials and retain natural features instead of clear-cutting a property.

In Gainesville, developers of Madera used LID to achieve zero stormwater discharge from residential lots, while cutting in half annual home energy and landscape maintenance costs over conventional development.

State and federal regulators have been supportive of LID concepts. Drawing on research, including FDEP and water management district funded studies of the effectiveness of berms and swales, and pervious parking materials at the Florida Aquarium and ongoing research on green roofs by the University of Central Florida, state officials hope to have a new stormwater rule in place by next July that actively promotes LID practices.

Water management districts have taken a cautious stance, expressing concerns about the ability to monitor long-term maintenance of decentralized lot-level stormwater treatment features that could replace the centralized stormwater ponds permitted today. Another concern is the manner in which a high groundwater table can impact the effectiveness of some LID methods. But they too are taking encouraging steps forward with plans for an LID workshop later this year.

Developers also are expressing interest, but until local development codes and current permitting requirements change to allow alternatives or provide incentives, they are likely to maintain the status quo.

Industry professionals can play an important role by advancing the discussion and helping to promote LID-friendly policies and practices at all levels.

The National Association of Home Builders' Guidelines for Green Building is an outstanding example of leadership in this direction. It recognizes the importance of low-impact site planning and land development in lessening a subdivision's overall impact on the environment and reducing infrastructure costs.

Local governments are on the front lines and will ultimately bear the financial burdens of responding to new mandates for reducing stormwater pollution.

The time to act is now.

Several steps can be taken to ensure a more ecologically sustainable future:

* Local governments should review their land development codes to identify and remove impediments to low-impact development, promote LID through model ordinances, and provide incentives such as fast-track permitting or reduced fees for developers who pursue these options.

* Communities can work with the water management districts to identify types of development where LID can more easily be controlled, including commercial sites and multi-family residential dwellings such as townhouses and condominiums.

* The state should continue to fund additional pilot studies to determine appropriate credits for certain practices and improve LID design techniques, particularly for nutrient removal.

Communities can no longer afford to conduct business as usual. The financial and environmental stakes are simply too high. Let's embrace a better path.

Elie G. Araj, PE, is president of Applied Sciences Consulting Inc. in Tampa and former environmental program manager of Hillsborough County's stormwater management department. He can be reached at elie.araj@applied sciencesci.com.