Water conservation

Preserving natural vegetation is part of a Florida Water Star^SM -certified home and of LID.

Low impact development (LID)

A new approach to water management

The need

In Florida, untreated stormwater runoff contributes to the pollutants entering our rivers, lakes and streams. Untreated stormwater runoff carries road residues, pesticides, fertilizers, pet wastes and other pollutants into our waterways. An estimated 80 to 95 percent of the heavy metals (copper, lead and cadmium) entering Florida waters are the result of untreated stormwater runoff. Natural processes that would otherwise retain, cleanse and filter storm water have been reduced by the impervious surfaces — roads and rooftops — associated with traditional urban development.

What is LID?

Low impact development (LID) is an approach to land development that uses various land planning, design and construction practices to simultaneously conserve and protect natural resource systems while reducing infrastructure costs. LID stands apart from other concepts through its emphasis on cost-effective strategies at the lot level. Designing an individual site to replicate predevelopment hydrology can reduce the project’s impacts on natural systems.

LID and water conservation

Florida’s available water supply will, in the not too distant future, be surpassed by the population it supports. Reducing stormwater runoff is only half of the equation in stretching our water supply to its fullest potential. Water conservation — whether on the lawn or inside the home — must become a more widespread way of life. In 2008, total freshwater use was more than one billion gallons per day in the 18-county region within the St. Johns River Water Management District. Public water supply use represents nearly half of this amount, making it the largest water use category in the District.

To preserve the quality of life and Florida’s natural systems, it is important to consider different ways of developing communities and implementing new ideas.

The District developed Florida Water Star^SM, which is similar to the federal Energy Star® program, to provide criteria for demonstrating water savings through water efficient household appliances, plumbing fixtures, irrigation systems and landscapes. In addition to homes, the program has certification criteria for commercial properties and communities. Homes are certified under a tiered system and qualifications points lists offer ways for every property owner to succeed in obtaining certification for their water efficiency efforts both indoors and in their landscapes. Numerous local governments support Florida Water Star^SM through incentives and rebates, and the program is offered in the St. Johns River, South Florida and Southwest Florida water management districts.

Benefits

LID strategies move away from a centralized method of collecting, conveying and discharging water to one that minimizes both impervious areas and stores and treats storm water in a more distributed fashion, sometimes even on the individual lot level.

Uniformity is generally the rule with traditional developments. In traditional developments, houses may be fronted by St. Augustine sod and serviced by a centralized stormwater system that may include a retention pond. In contrast, LID allows and encourages the integration of treatment and management measures into individual lots or house sites. Strategic placement of distributed lot-level controls — such as preservation of natural on-site wetlands — can be customized to closely mimic a watershed’s natural hydrology. The result is a hydrologically functional landscape that generates less surface water runoff, less pollution and erosion, and reduced overall damage to lakes, streams, rivers and coastal waters.

Challenges to LID

Incorporating LID into new development faces several challenges. Contractors and their subcontractors may need to change customary construction practices to accommodate LID. Some subcontractors may need to receive additional training to learn how to properly install irrigation systems and landscaping, and learn about evolving LID technologies. Local regulations, ordinances and codes may need to be modified to allow for changes in design and construction. Regulatory staff may need to become more familiar with both the benefits and limitations of LID practices.

The District works closely with applicants applying LID concepts to projects. Senior District regulatory staff members are trained in how to review systems that employ LID practices. Attention is given to matching appropriate practices with site specific needs.

Common LID practices

Many different types of LID practices can be used and new practices are being created. Some common LID practices include

• Vegetated swales, buffers and strips
• Narrower streets without curbs and gutters
• Curb cutaways for median storage
• End-of-island bioretention cells
• Permeable pavers
• Green roofs
• Rain gardens and bioretention
• Tree or natural area preservation
• Rain gardens, rain barrels or cisterns
• In-ground infiltration and storage
• Green build programs such as Florida Water Star^SM

For additional information about LID, contact Deirdre Irwin at (386) 546-8437 or Mike Register at
(386) 329-4212.