Projects

Determination of Landscape Irrigation Water Use in Southwest Florida

Sponsor: Southwest Florida Water Management District

Timeline: 5/1/2010 – 12/31/2015

Abstract:

It is important to have an accurate baseline of existing water use to track impact of future conservation efforts. Currently, only scattered and isolated data of irrigation water use on residential homes in southwest Florida exist. It is difficult to assess the current efficiency of irrigation water use and to benchmark conservation efforts without measuring representative irrigation water use data in the DISTRICT. Then, it is important to measure the effectiveness of FFL’s practices.

There is no existing representative database of actual landscape irrigation water use in Florida. Public Supply Utilities routinely meter potable water delivery for billing purposes. For purposes of this project, public supply is defined as potable drinking water provided by a public or private utility. However, use of existing meter data is complicated by several factors. First, most utility meter data include both indoor and outdoor use. In warm climates such as central and south Florida, separation of indoor and outdoor use by assuming zero irrigation in the winter is not a valid assumption (Haley and Dukes, 2007; Mayer et al., 1999). The turf, landscape and irrigation system quality and composition also influence water used for residential irrigation. Meter data will vary as the size of the irrigated area varies. Thus, volumetric water data need to be normalized based on the irrigated area. Irrigated area is not typically collected by utilities. These data are available from property appraiser databases; however, substantial errors can exist when assuming that pervious area is equal to irrigated area. Issues associated with measuring unmetered reclaimed water for irrigation or from a shallow well are beyond the scope of this project. Given the noted challenges, it is necessary to develop a hybrid monitoring program that will use existing utility and property appraiser data to determine irrigation water use throughout the DISTRICT. Water use patterns for irrigation among residential and small commercial establishments are assumed to be fairly consistent; however, large landscapes are associated with additional variables and are therefore not included in this proposed study. This PROJECT will use Automatic Meter Recording (AMR) devices on subsets of utility customer bases throughout the DISTRICT to monitor utility meters at a high frequency (i.e. every 5 or 10 minutes). This frequency of monitoring will allow the separation of relatively low volumetric uses inside the house compared to the higher irrigation water use. Thus, the irrigation water use can be determined from select customers without solicitation of the customers.