Maintaining and replenishing Hawaii’s water supply is a top priority for the Department of Land and Natural Resources this legislative session. In particular, the agency wants $11 million per year to carry out a plan that would double the acreage of protected rainforest watersheds in the next 10 years, DLNR Deputy Director Guy Kaulukukui said Wednesday.
Already, $5 million was allocated for actions outlined in the plan, such as fencing and removing invasive animals from priority areas, which DLNR Division of Forestry and Wildlife managers helped select. More work will likely be done in West Hawaii than East Hawaii, he said.
However, for the plan to be successful, action must occur on a large scale. Currently only 10 percent of the priority watershed areas are protected — something that took 40 years to achieve, Kaulukukui said.
Kaulukukui’s presentation was one of six shared at West Hawaii Civic Center during an informal public forum on the status and use of the island’s water resources. Topics included Kahaluu watershed, using wastewater as a resource and Kohanaiki’s water-quality monitoring program.
Despite tight fiscal times and some resistance, Kaulukukui said funding is needed to ensure water availability and protect the supply from threats. DLNR wants dedicated funding so it doesn’t have to continue to argue for it, and some think the money should come out of the general fund because fresh water is so fundamental, he said.
The remaining $6 million being requested not only helps mauka areas, but will be used for nearshore fisheries, manifesting an ahupuaa approach to resource management that takes into account the interconnectedness of natural resources. Kaulukukui said the issue is urgent based on evidence showing declines in rainfall, stream base flow and water levels for selected wells, as well as trends indicating hotter, drier conditions. Forests, which can increase water capture up to 30 percent, are being ravaged by invasive species and other threats. The ecosystem is so out of balance it cannot recover on its own, he said.
He said education is a critical component to achieving goals. There’s a lack of public awareness about more than 500 watersheds statewide and how they provide nearly all of Hawaii’s water, which is why DLNR produced a half-hour television program and a 16-page magazine.
Presenter Don Thomas of the University of Hawaii Center for the Study of Active Volcanoes explained how little scientists know about the island’s hydrology cycle, an understanding needed to better manage resources. He shared how the standard Hawaii hydrology model, produced 70 years ago, was too simple and did not show the full picture — something proved by the Hawaii Scientific Drilling Project, funded more than 20 years ago.
The National Science Foundation drilled a 11,551-foot hole — the deepest hole that’s ever been drilled into an ocean island — near Hilo International Airport to look at the history, structure and evolution of Hawaiian volcanoes. It discovered lots of unexpected freshwater, including layers of freshwater after they passed through the saltwater they anticipated to find, Thomas said.
“We encountered perhaps a half a dozen to a dozen separate layers where freshwater was present. These layers were interspersed with zones of rock that were saturated with seawater, something not at all what we expected,” he said. “The freshwater in many of these aquifers was artesian, and there was evidence of freshwater extending down to 10,000 feet below sea level. … We had a well flowing at a rate of about 2,000 gallons a minute of freshwater coming out completely spontaneously from a system encountered at a depth of about 1,000 feet below sea level.”
The foundation estimated half a billion gallons of freshwater was moving through the system daily and discharging well below sea level. Scientists now think similar conditions might exist elsewhere on the island, and Thomas plans to find out when a well observation project begins monitoring three sites in the Mauna Kea/Mauna Loa saddle region. Drilling of the first site is anticipated to begin by early October. The draft environmental assessment should be published at the end of the month, he said.