APPENDIX 3C OUTDOOR WATER CONSERVATION

Transcription

1 APPENDIX 3C OUTDOOR WATER CONSERVATION 1

2 Outdoor Water Conservation Purpose The purpose of this Section is to provide strategies for reducing outdoor water use associated with landscape irrigation. As part of this effort, recent studies, existing requirements and proposed criteria were reviewed relative to irrigation efficiency and low-maintenance landscaping strategies. Relevant water conservation and certification programs that were reviewed included: Comprehensive Plan Goals, Objectives and Policies Land Development Regulations Ordinances Florida Green Building Coalition certification programs Florida Water Star Gold Certification Program EPA WaterSense Background During the naturally recurring dry seasons and droughts that are part of the seasonal and periodic ebb and flow in Florida, homeowners are often asked to conserve water. The effects of such droughts are typically most severe in April, May and early June. In addition, irrigation needs for turf and landscaping vary significantly from month to month based on the supplemental irrigation demands of the applicable landscape material. However, irrigation control system timers are very often set for the driest months (i.e. highest demands). Figure 1.1 illustrates the typical monthly variations in supplemental irrigation demands for turf grass for a 1-in-10 year drought event using SWFWMD s modified Blaney-Criddle methodogy for the Peace River Manasota region. The horizontal red line corresponds to an average monthly irrigation application of 4-inches based upon a weekly application of 1-inch. As indicated in Figure 1.1, while a 1-inch/week application rate may in fact be needed during April and May, such application rates may be unnecessary for other months of the year when evapotranspiration is lower and/or rainfall is higher. Therefore, the practice of maintaining the use of higher application rates can result in over-irrigation, and place greater stress than necessary on source water supplies. The water conservation strategies for irrigation and landscaping contained herein are intended to reduce landscaping water demands and provide irrigation water in an efficient and as-needed basis, consistent with existing requirements and certification programs. By designing irrigation and landscaping conservation strategies up front, the Peace River Manasota region can promote healthy landscapes while reducing outdoor water demands by as much as 50% or more when compared to conventional irrigation system designs. 2

3 Irrigation Application (in inches) 6.0 Irrigation Requirements for Turf Grass Figure 1.1 Monthly Irrigation Demands for Turf Grass (1-in-10 year drought) Applicable Research Recent research projects undertaken by the University of Florida (UF) on behalf of the Southwest Florida Water Management Districts (SWFWMD) were reviewed and are reviewed below as key building blocks to the outdoor water conservation plan. Soil Moisture Sensors SWFWMD (inches) Recent and on-going research by the UF for the SWFWMD has shown that soil moisture sensors (SMS) used to control irrigation for residential landscapes can significantly and reliably reduce water use. Similar to rainfall sensors but less susceptible to exposure and more indicative of the actual water needs of plant root systems, SMS are installed and wired to override the irrigation control system if adequate water exists in the soil. SMS technology has been used successfully for agricultural irrigation for a number of years, but has not been broadly applied in residentialcommercial landscape settings. However, UF s research has shown that SMS can reduce irrigation water use by at least 50% in such settings. In particular, SMS hold great promise when considering the variation in true monthly irrigation needs vs. the homeowner s tendency to set and maintain their irrigation control timers based upon the worst case irrigation demands of April and May. With respect to recent SMS research, the following documents prepared by the UF for the SWFWMD were obtained and reviewed. 3

4 Evaluation of Soil Moisture Based On-Demand Irrigation Controllers, Interim Project Report (October 29, 2004) Evaluation of Soil Moisture Based On-Demand Irrigation Controllers, Phase II Progress Report 3 (July 23, 2007) Evaluation of Soil Moisture Based On-Demand Irrigation Controllers, Interim Progress Report 5 (July23, 2007) Field Guide to Proper Installation, Calibration, and Maintenance of Soil Moisture Sensor Control Systems in Residential Florida Landscapes (2007) Figure 1.2 presents various types of soil moisture sensors. The research indicated that the Acclima consistently exhibited the best performance. Figure 1.2 Typical Soil Moisture Sensors Figure 1.3 presents the results of residential irrigation data collected over a 5-month period for three groups of 15 homes located in Pinellas County. This data illustrates the relative water savings and specifically that homes with conventional timer-based controls applied 4

5 approximately 7.4 inches (189 mm); homes with properly functioning rain shutoff override applied approximately 5.9 inches (150 mm); and homes with properly function soil moisture sensor override applied approximately 2.9 inches (74 mm). Landscaping Figure 1.3 Comparison of Irrigation Applications with various Controllers A study entitled Residential Irrigation Efficiency Assessment Monitoring and published in 2005 by the UF Institute of Food and Agricultural Sciences (IFAS) for the St. John s River Water Management District (SJRWMD) was also reviewed. This study found that homes with an irrigation system designed according to specifications for optimal efficiency, including a landscape design that minimized turfgrass and maximized the use of Florida water-wise plants, consumed considerably less water than typical landscapes and irrigation systems. Figure 1.4 present the graphical results of this study. 5

6 Figure 1.4 Monthly Water Use (from Residential Irrigation Efficiency Assessment Monitoring) The corresponding treatments in Figure 1.4 are as follows: T1 homes with existing irrigation systems and typical landscape plantings, where the homeowner controlled the irrigation scheduling. T2 homes with existing irrigation systems and typical landscape plantings, with time clocks adjusted on a seasonal basis to replace 60% of historical ET. T3 homes with an irrigation system designed according to specifications for optimal efficiency, including a landscape design that minimized turfgrass and maximized the use of Florida water-wise plans. As indicated in Figure 1.4, once established, homes landscaped and irrigated in accordance with condition T3 can reduce water use by at least 25%. 6

7 Florida Green Building Coalition Certification Programs The Florida Green Building Coalition (FGBC) has certification programs for site development, residential homes, residential high rises, and commercial buildings. These certification programs all contain a check list with water-related points. The following excerpts are provided for each FGBC certification program relative to the landscape and irrigation checklists. FLORIDA GREEN BUILDING COALITION SITE DEVELOPMENT Prerequisites None Category 3: Green Utilities Practices - Outdoor (Minimum of 12 points required including others) U-3 Supply irrigation system with storm or reuse water 15 U-4 Irrigation meter system 5 U-5 Water irrigation budget 10 U-6 Submeter parcels by end user 5 Total points 35 Category 4: Amenities - Outdoor (Minimum of 5 points required including others) A-5 Golf Courses is Audubon International certified or excluded 6 A-6 Landscape criteria and management plan for common areas and amenities 6 Total points 12 7

8 FLORIDA GREEN BUILDING COALITION RESIDENTIAL HOME Category 2: Water - Outdoor (Minimum of 14 points required including indoor) Prerequisites Waterfront Considerations: Use native aquatic vegetation in shoreline area No turf adjacent to water (low maintenance plants instead) Use of terraces, swales, or berms to slow storm water Home site does not border natural water body Reclaimed Water Reuse For irrigation 2 Meter on reclaimed irrigation system 2 Volume based pricing arrangement 2 For toilet flushing 2 Installed Landscape Drought tolerant turf, no turf in densely shaded areas 2 50%, 80%, 100% of plants/trees from Water-wise: Florida Landscapes or local drought tolerant list Plants/trees selected to be compatible w/local environment/microclimate 2 Turf less than 50% of landscape 3 Evenly shaped turf areas, no turf on berms 2 Plants with similar maintenance requirements grouped together 2 Mulch applied 3-4 inches deep around plants 2 Non Cypress mulch used 2 Soil tested and amended where necessary 2 No permanent installed irrigation system 10 Innovative irrigation technology 2 Meet or exceed Florida Water Star standards 5 > 10,000 sq. ft. irrigated to FGBC standards 1 7,500 9,999 sq. ft. irrigated to FGBC standards 2 5,000 7,499 sq. ft. irrigated to FGBC standards 3 2,500 4,999 sq. ft. irrigated to FGBC standards 4 1 2,499 sq. ft. irrigated to FGBC standards Total points 60 8

9 FLORIDA GREEN BUILDING COALITION HIGH RISE RESIDENTIAL Category 2: Water - Outdoor (Minimum of 3 points required including indoor) Prerequisites Drought Tolerant Landscape 25% Credit 1.1 Drought Tolerant Landscape 50% 1 Credit 1.2 Drought Tolerant Landscape 75% 1 Credit 1.3 Drought Tolerant Landscape 100% 1 Credit 2.1 Water Efficient Irrigation, Reduce Potable Water Use for 50% of area 1 Credit 2.2 Water Efficient Irrigation, Reduce Potable Water Use for 75% of area 1 Credit 2.3 Water Efficient Irrigation, Reduce Potable Water Use or No Permanent Irrigation 1 Credit 6 Florida Yards & Neighborhoods Certified 1 Total points 7 FLORIDA GREEN BUILDING COALITION - COMMERCIAL Category 2: Water - Outdoor (Minimum of 3 points required including indoor) Prerequisites Drought Tolerant Landscape 25% Credit 1.1 Drought Tolerant Landscape 50% 1 Credit 1.2 Drought Tolerant Landscape 75% 1 Credit 1.3 Drought Tolerant Landscape 100% 1 Credit 2.1 Water Efficient Irrigation, Reduce Potable Water Use for 50% of area 1 Credit 2.2 Water Efficient Irrigation, Reduce Potable Water Use for 75% of area 1 Credit 2.3 Water Efficient Irrigation, Reduce Potable Water Use or No Permanent Irrigation 1 Florida Water Star Gold Certification Program Total points 6 The Florida Water Star Certification (FWS) was launched in 2006 and is service-marked by the SJRWMD. The Southwest Florida Water Management District (SWFWMD) in coordination with the SJRWMD developed the Florida Water Star Gold Certification (FWSG) program. SWFWMD is also currently working to incorporate it into the existing Florida Green Building Coalition (FGBC) certification. The following excerpts are provided from SWFWMD s FWSG certification program relative to the landscape and irrigation checklists. 9

10 Landscape (Minimum of 70 points required) Prerequisites All state, county, and municipal codes must be met and will supersede items in the prerequisites or points list unless Florida Water Star Gold Certification requirements are more stringent. Prereq Description Yes No LS PR 1 - Landscape areas that are irrigated by high volume shall not exceed 50 percent of the total landscaped area. LS PR 2 - Plant root balls are at least 2.5 feet on center from the foundation of any structure. LS PR 3 - If an in-ground irrigation system is used, turf grass and landscape bed areas are distinctly separate and micro-irrigation is used in landscape beds. LS PR 4 - Organic byproduct/alternative mulches shall be used, such as pink bark, melaleuca, pine needles, or shredded wood debris. LS PR 5 - Mulch is applied to a depth of 2 to 4 inches, leaving a 2-inch clear space around stems/trunks of plants/trees. LS PR 6 - No invasive plant species are on-site. Invasive plants are defined as those identified by the University of Florida/Institute of Food and Agricultural Sciences Assessment of Non-Native Plants: LS PR 7 - Florida Water Star - Gold Certification requires that all plants be installed according to Florida Green Industry best management practices. The installer of the landscape must attest to this. The documentation must be received prior to certification. (See attached.) Point LS CR 1 LS CR 2 Point LS CR 3 Description Preservation of Existing Vegetation Choose the option that best applies: - 30% or more of the preserved landscape covered by existing or non-invasive trees, shrubs, or ground covers (not including conservation easements) % or more of the preserved landscape covered by existing or non-invasive trees, shrubs, or ground covers (not including conservation easements) % or more of the preserved landscape covered by existing or non-invasive trees, shrubs, or ground covers (not including conservation easements). 5 - Four or more existing trees or palms greater than 4 inches in diameter at breast height (dbh) are preserved. 15 Description Built Landscape or Naturally Vegetated Site - Plant selections are compatible with soils and other site-specific growing conditions Up to 15 LS CR 4 - Plants are grouped with similar moisture and maintenance requirements Up to 15 Choose the option that applies: LS CR 5 - High-water use area is less than 40% of the total landscaped area 10 - High-water use area is less than 30% of the total landscaped area 15 LS CR 6 - Landscape beds have no permanent in-ground irrigation system Up to 25 LS CR 7 - Planted trees will provide shade up to 40% of landscaped area at maturity 15 LS CR 8 - Maintenance instructions for recommended fertilizer and pesticide applications for both turf and beds permanently posted next to the irrigation controller. 5 LS CR 9 - Organic soil amendments have been incorporated into top layer of existing soil. (Amendment of at least 5% of the soil weight recommended). 10 LS CR 10 - Downspouts are directed to pervious areas, outfall is 2 or more feet of foundation. 5 LS CR 11 - can be awarded for the installation of new and innovative water conservation technology and features. Up to 10 Subtotal

11 Property Bordering a Water Body (Minimum of 10 points required) A letter of modification to the permit must be received by the administrator prior to grant certification. Point WB CR 1 WB CR 2 Description - A 6-foot border of non-irrigated, unfertilized site-appropriate plants is established on the lot between the lawn and shoreline/seawall to absorb nutrients. - Non-irrigated and unfertilized vegetated terraces, swales, or berms are used to prevent storm water from entering the water body. Up to 10 Up to 10 Subtotal 20 Possible maximum landscape total

12 Irrigation (Minimum of 50 points required) Prerequisites Irrigation design and installation shall meet or exceed all state, county, and municipal codes and will supersede items in the prerequisites or points list. Prereq Description Yes No IRR PR 1 IRR PR 2 IRR PR 3 IRR PR 4 IRR PR 5 IRR PR 6 IRR PR 7 IRR PR 8 IRR PR 9 IRR PR 10 IRR PR 11 IRR PR 12 IRR PR 13 IRR PR 14 IRR PR 15 IRR PR 16 IRR PR 17 - If irrigation is used for landscape beds, micro-irrigation is used and is properly installed - Irrigation zones for turf grass and landscape beds are separate - High volume irrigation shall not exceed 50% of the irrigated area - Sprinklers and emitters are located 2 feet from structures, at minimum - Irrigation system is free from leaks - Pipes are sized for appropriate flows to prevent velocities greater than 5 feet per second (fps) - Application rates for all sprinklers and emitters within a zone shall be matched - Head spacing does not exceed 90% of the nozzle throw radius - Rotor heads and fixed pattern spray heads shall not be installed in the same zone and do not overlap - Pop-up sprinklers heads sufficiently rise above turf grass height - Application occurs in proper spray patters, minimizing overspray on impervious surfaces - Sprinklers in low-lying areas have check valves - A rain shut-off device is installed in an operable location and is functioning - Irrigation controller contains a battery backup or non-volatile memory to maintain schedule settings Each of the following items in stalled adjacent to controller: Controller handbook/operating instructions Zone diagram Specific zone application rates and maintenance run times Soil moisture sensor probe location, when applicable Option A: Irrigation controller is set on a regular maintenance schedule (i.e. 1 day/week) for a properly scheduled amount of time Option B: The controller has specific run times posted if it is operating more than 1 day per week for plan establishment The irrigation schedule for maintenance does not exceed 21 gallons (34 inches) per sq. ft. annually Choose the option that best applies: Description 12 High-volume irrigation is less than 40% of the landscaped area 15 IRR CR 1 High-volume irrigation is less than 30% of the landscaped area 20 IRR CR 2 Pressure-regulated valves are installed for spray zones 5 IRR CR 3 Pressure-compensating spray heads are installed for spray zones 10 IRR CR 4 Leak detection shutoff system is installed 5 IRR CR 5 In-line pressure regulator limiting pressure to 65 psi or less installed 5 IRR CR 6 can be for only one of the following three options: Soil moisture sensor (SMS) with one SMS probe is properly installed, using approved water tight spliced connectors in the valve box, and is correctly functioning Soil moisture sensor (SMS) with multiple SMS probes is properly installed, using approved water tight spliced connectors in the valve box, and is correctly functioning ET, Smart, or weather-based controller is properly installed, programmed, and functioning 15 IRR CR 7 Non-potable water source used for irrigation, not including any type of well 5 IRR CR 8 No permanent in-ground irrigation is used for site-appropriate/drought-tolerant landscape material Up to 90 IRR CR 9 Innovative irrigation water conservation Up to 10 TOTAL Total irrigation points

13 EPA WaterSense Certification WaterSense is a program sponsored by the U.S. Environmental Protection Agency (EPA) to identify and promote water-efficient products and practices through a certification label program. With respect to landscape irrigation, WaterSense certifies professionals and technologies in water-efficient irrigation expertise and efficiency. Irrigation Professionals EPA has established specifications to recognize certification programs for irrigation professionals in three areas: system design, installation and maintenance, and system auditing. The following web link provides a listing of the current certified professionals by State: Weather-Based Irrigation Controllers WaterSense has also developed specifications for weather-based irrigation controllers. WaterSense labeled irrigation controllers act like a thermostat for irrigation systems, turning them on an off using local weather and landscape conditions to meet actual site conditions. Instead of irrigating using a controller with a clock and a preset schedule, WaterSense labeled controllers allow watering schedules to better match plants' water needs. With proper installation, programming, and maintenance, homeowners and businesses can use WaterSense labeled controllers instead of standard clock-timer controllers. To earn the WaterSense label, landscape irrigation controllers must be able to adequately meet the watering needs of a landscape without overwatering. As with all other WaterSense labeled products, WaterSense labeled controllers are independently certified to ensure that they meet the WaterSense criteria for efficiency and performance. It is estimated by EPA that replacing a standard clock timer with a WaterSense labeled irrigation controller can save an average home nearly 8,800 gallons of water annually. Soil Moisture Sensors To help increase water efficiency outdoors, WaterSense has issued a Notice of Intent to develop a specification for soil moisture based control technologies, which will complement the existing weather-based irrigation controller specification. Soil moisture based control technologies water plants based on their needs by measuring the amount of moisture in the soil and tailoring irrigation schedules accordingly. Studies suggest that soil moisture sensors can result in water savings of at least 20 percent, potentially saving millions of gallons of water across the country. Soil moisture based control technologies that earn the WaterSense label will take the guesswork out of watering and help improve irrigation system efficiency. 13

14 Recommendations Emerging trends in water management, land use planning, and related regulatory requirements are compelling water utilities and large-scale community developments to explore opportunities to better conserve water and to use alternative water supply sources. Although the Peace River region is in the Southern Water Use Caution Area, home buyers are likely to continue to demand that their communities contain attractive landscaping amenities. To maintain a competitive advantage in such a marketplace will require the effective implementation of emerging water conservation technologies that can substantially decrease water use without compromising the aesthetic expectations of consumers. Fortunately, opportunities exist to explore and take advantage of new technologies and water management techniques that can accomplish this goal. The following recommendations are provided in the context of aforementioned certification programs and in consideration of emerging irrigation efficiency technologies. With the exception of the prerequisites for waterfront considerations as indicated in the residential home criteria on page 8, it appears that the FGBC certification program is generally consistent with many of the landscape and irrigation ordinances for the Authority member governments and customers. While it may be premature for the Authority member governments and customers to commit to meeting the FWSG certification program, its evolution should be actively monitored and its benefits carefully evaluated. Consider requiring all irrigation design, installation and auditing contractors to be WaterSense certified. The various certification programs provide opportunities for additional credit points for innovative landscaping and irrigation water management. It is recommended that the Authority member governments and customers investigate the development of landscape designs that integrate soils, roots, plants, and water use to reduce water and fertilizer use. 14