Public utilities and water supply managers and our citizens will not benefit from public policies promising water conservation and not delivering. Our public utilities and all Florida citizens should only support those landscape water use conservation strategies that demonstrate and quantify numbers of gallons conserved and available for reallocation. Proposed quantifiable solutions must also satisfy reasonable cost/benefit analysis. I believe the State of Florida, our cities, counties, water utilities and the Florida Green Industry must support establishment of an enforceable landscape water use conservation standard, based on good science and empirical data.
I wish to present a multifaceted strategy to conserve 50% or more of the current landscape water used annually and primarily by those residences with in-ground irrigation systems.
Based on Hillsborough County water use data, many homeowners with in-ground irrigation systems use, on average, 22,000 gallons per 1,000 SF of landscape area per year, or 110,000 gallons/year. Unpublished soil moisture sensor research confirms: most homeowners overwater existing landscape plants and turf by 50-75% on average. Overwatering turf or landscape plants contributes to shallow roots, reducing plant vigor, decreasing drought tolerance, increasing pests and disease, increasing pesticide and fungicide use, contributing to increased stormwater runoff, contaminants, and ground water pollution.
I believe most Florida citizens will support conservation strategies supported by good science. I believe many new industry innovations and technologies, quantifiable strategies, and creative design solutions are on the near horizon and will further aid in decreasing landscape water use. As a landscape architect, I personally support priority investment in rebuilding and reestablishing soil ecosystem biological functions within disturbed fill soils, urban soils, sandy soils, clay soils, wet soils, and dry soils found within new and existing landscapes. Improving soil organics with compost will play a significant role.
The proposed Sustainable Landscape Water Conservation Allowance and Conservation Standard is expressed as up to 11,000 gallons per year per 1,000 SF of landscape area. We then quantify, enforce, and support the proposed conservation standard with two simple strategies:
- A landscape water meter is required for all new and existing in-ground irrigation systems, public or private. The cost incurred by utilities to purchase, install, and monitor landscape meters should be easily integrated into the rate structure.
- A tiered rate structure for landscape water use is required; the lowest rate is charged for use at or below the Landscape Water Use Annual Allowance (11,000 gallons per 1000SF). For those exceeding their allowance, water rates should double for up to 40% use over the established allowance, and rates should triple for water used and exceeding 40% over-allowance amounts. The highest rate should reflect the cost and charges for RO water.
There should probably be a solid discussion of reallocating the money spent creating and enforcing regulations to:
- The cost of the water meter installation;
- The education of the residential user;
- The “cost sharing” incentives (NOT rebates) to large water users to jump-start aggressive landscape water reduction plans and implementation. (This should be done by properly credentialed professionals!)
With reduced ink and very few new regulations, I believe the Sustainable Landscape Water Use Conservation Program will deliver significant quantifiable results within the first year. Incentives should be provided for homeowners consistently using 50% less water than their ‘allowance’.
David Drylie is owner and landscape architect at Green Images Nursery in Orlando, Florida. He may be contacted at firstname.lastname@example.org
Editor's Note: This proposal is a version of the water-budget approach now used successfully in over three dozen cities in the U.S. and outlined in the new EPA WaterSense for new homes guidelines.