Column: We can do much today to invest in our isles’ water systems By Dana Okano November 1, 2018 Updated October 31, 2018 8:23pm
If you’ve never experienced it before, it’s hard to imagine a day without water. But considering our isolated geography and changing climate, we should all take a moment to imagine what such a day would mean to our lives. Recent findings have raised concern about long-term fresh water security for our islands. University of Hawaii and other scientists have documented troubling trends, including reduced rainfall, higher evaporation rates and declining stream flows in recent decades. These findings suggest that Hawaii is entering an era of fresh water uncertainty. Approximately 60 percent of Hawaii’s potable water supply is from groundwater aquifers, and for the urban core of the City and County of Honolulu, groundwater is 90 percent of the potable water supply. Groundwater is recharged by precipitation events. There has been reduced rainfall of 22 percent across the state of Hawaii over the past 30 years, and climate models show trends that drier areas will get drier and wetter areas will get slightly wetter. Hawaii’s watershed forests are the primary source of freshwater capture, and only half of those remain, with only 10 percent of the remaining acres currently in active protection. The scale of changing rainfall patterns, plans for increased local food production, and land use changes demand a proactive and coordinated response to water security that protects a sustainable and affordable water supply.