A comprehensive approach to an urban water reuse system to meet irrigation demand and conserve water: City of Cape Coral, FL, USA

Abstract

Maximizing the reuse of domestic wastewater is a critical objective, spurred by the pressing need to avoid water loss, reduce environmental discharges, and manage irrigation water demand. In the City of Cape Coral (FL, USA), thousands of old-fashioned and inefficient irrigation systems have been installed over the past 50 years. The city has adopted year-round external water use restrictions, but demands continue to increase. In 2020, peak 24-h irrigation water demands exceeded 177,914 m3. In response to recurrent dry seasons and growing demand over the past 20 years, the city has diversified its water resources. The city uses brackish groundwater with reverse osmosis treatment to produce drinking water and reuses 100% of its wastewater effluent for irrigation by blending the treated wastewater with fresh water from 483 km of freshwater canals. To promote efficient irrigation water use among consumers, a new approach has been adopted to automate private irrigation systems. The Environmental Resource Assessment and Management System Integrated Urban Water Model was used to simulate water management scenarios. The simulation showed that increasing automatic irrigation efficiency can save millions of cubic meters of irrigation water and help the city meet the future build-out peak-day demand of 219,758 m3/d, as estimated by the Blaney–Criddle method.