Maui's freshwater : status, allocation, and management for sustainability

Abstract

The water system on Maui Island in Hawaii is an integral part of the island’s infrastructure, affecting energy, agriculture, waste, and domestic systems. Both the built and the natural water systems are likely to be altered over the coming decades. Maui’s two major industries are agriculture and tourism, which compete for water and land resources. Maui faces high costs for food and fuel it must import, and agricultural efforts might shift from plantation-scale monocropping to energy production or diversified agriculture for food. Simultaneously, land use changes (like deforestation), climate change, and cyclical droughts affect Maui’s freshwater supply. Water planning and management based on careful assessment can be valuable tools for a community expecting that water will become increasingly scarce. Since water plays a large role in many other systems, choices about water allocation and use can help the island move toward solutions of multiple problems at once, including energy scarcity, coastal protection, and financial health. This work provides a dynamic snapshot of Maui’s current built and natural water systems, then analyzes two potential water management actions: pumped storage hydroelectric facilities built on existing reservoirs and use of secondary treated wastewater to irrigate biomass for power. Based on cost estimates and alternative solutions, neither of these applications are currently judged viable.