Part 1 Many old-timers lament that Kaua‘i is dryer than it used to be. Even my peers comment that the amount of water in places like the “blue room” in Ha‘ena, or swimming holes we would spend days enjoying, is
Part 1
Many old-timers lament that Kaua‘i is dryer than it used to be. Even my peers comment that the amount of water in places like the “blue room” in Ha‘ena, or swimming holes we would spend days enjoying, is drastically lower. This observation may be worth paying some careful attention to.
I spent the past few days attending the 2009 Hawai‘i Conservation Conference on O‘ahu, hosted by a cooperative partnership of 15 government, education and nonprofit organizations. Titled “Hawai‘i in a Changing Climate,” the conference was three full days of both inspiring and alarming lectures by scientists, policy makers, cultural practitioners, and community leaders.
I found myself thirstily drinking during the conference as I listened to leading scientists from universities and government talk about the latest climate data and associated effects on our water supply. Climate change impacts will (and already do) include too much water, too little water and degraded water quality — all contributing to less freshwater for drinking and agriculture.
On Kaua‘i, groundwater is a vital resource. Kaua‘i Department of Water operates 13 separate, unconnected water systems that pump water from 48 underground wells and tunnels to deliver water to a majority of island homes and businesses. Contained in porous geological formations called “aquifers,” fresh groundwater floats on and is surrounded by more dense saltwater from the ocean. Recharge from rainfall, pumping, and saltwater intrusion all influence the availability of groundwater on tropical Pacific islands.
Gordon Tribble of U.S. Geological Survey reported that statewide data from 1913 through 2002 show significant decline in stream “base flow,” the amount of water that comes from groundwater discharge. All of the streams that were surveyed were not affected by upstream diversion or pumping, demonstrating an alarming trend in decreasing availability of groundwater over the past century.
Corresponding to decline in groundwater storage is evidence of decreasing rainfall. Over this same time period, rain gages with sufficient data commonly showed a downward trend. In 2008, Mount Waialeale received less than 330 inches of rainfall, as compared to the 460 inch average and 666 inch high of the 1980s. Key findings from the Global Climatic Data Center report that floods and droughts will become more common and intense. It is “most likely” that rainfall will continue to decline, and we will see further increase in extreme rain events, which could provide 50 percent to 70 percent of total annual rain in a few days.
Sea level rise resulting from global climate change also poses a grave threat to groundwater supply, as salt will intrude into aquifers and surface ecosystems. Chip Fletcher, University of Hawai‘i, urged the 50th state to plan for at least a three to four feet sea level rise. Future articles will further detail the multiple impacts of sea level rise, including erosion of beaches and bluffs, increased flooding and storm damage, marine inundation of low-lying areas, and higher water tables.
There is widespread consensus amongst scientists that climate change is upon us. Exact temperature rise, sea level increase, rainfall patterns, and other effects are impossible to forecast. However, general trends are being identified, and we must begin to adapt. Adaptation to climate change should be integrated into public policy setting, land use planning, agricultural systems, and the general public consciousness — the resilience of our community depends upon how we respond.
• Andrea Brower is project manager for Malama Kaua‘i, an organization committed to the ‘aina, community, and culture of the island. For more information visit www.malamakauai.org
