On May 20, the state Commission on Water Resource Management voted unanimously to accept a petition by the Honolulu Board of Water Supply to designate the Wai\u02bbanae aquifer sector as a ground water management area.<\/p>\n\n\n\n
The area incudes the aquifers for N\u0101n\u0101kuli, Lualualei, Makaha, Wai\u02bbanae, and Kea\u02bbau, and is the only sector on O\u02bbahu not yet designated.<\/p>\n\n\n\n
In voting to approve the petition, commissioner Lawrence Miike questioned why the Wai\u02bbanae sector had not already been designated, since demand as long exceeded the available supply, requiring the BWS to pump water in from the Pearl Harbor aquifer sector to meet about half of the sector\u2019s needs.<\/p>\n\n\n\n
Before the commission can vote to designate, a public hearings must be held, scientific information must be gathered to inform proposed findings of fact, and there must be further consultation with the May, City Council and BWS.<\/p>\n\n\n\n
If and when the Water Commission votes to designate, existing and new users will then have to apply for water use permits.<\/p>\n\n\n\n
At the Water Commission\u2019s May 20 meeting, program administrator for the BWS Water Resources Division Barry Usagawa explained how reliant the sector is on outside water, as well as the limitations of developing more capacity both within and outside the Wai\u02bbanae sector.<\/p>\n\n\n\n
Before voting to accept the petition, the Water Commission approved a scope of work for the BWS\u2019s Waianae Watershed Management Plan update, which will be part of the O\u02bbahu Water Use and Development Plan.<\/p>\n\n\n\n
Usagawa explained that the watershed management plan will be prepared by its consultant, SSFM. The plan will include projections low, medium, and high of demand and supply through the year 2045, as required by ordinance. <\/p>\n\n\n\n
\u201cBut that\u2019s not enough \u2026 when you\u2019re talking about sustainability,\u201d he said.<\/p>\n\n\n\n
\u201cThe rainfall forecasts, they\u2019re all looking at a drying trend. \u2026 When you start to look forward far enough, you start to run out of water at some point, and when you start doing that, then it drives specific actions that we should be setting sooner than later. So taking that longer-term look allows us to spread that cost out and then devise alternatives and work out those problems.<\/p>\n\n\n\n
So the plan will also include low and high projections to the year 2100. \u201cIt\u2019s a low and high because [the University of Hawai\u02bbi] has a low and high forecast [that] contribute to amount to sustainable yield we\u2019ll find in Wai\u02bbanae,\u201d he said.<\/p>\n\n\n\n
The plan is expected to be complete in 2027. Should the Water Commission vote to designate the sector, as appears likely, it would be in the midst of considering water use permits for the area when the plan is done.<\/p>\n\n\n\n
Commission chair Dawn Chang asked, \u201cWhile we\u2019re proceeding with our process, how do you see the integration with the planning process?\u201d<\/p>\n\n\n\n
\u201cIt\u2019s complicated,\u201d Usagawa replied. In applying for its water use permit, the BWS would seek an allocation that is \u201cmore tied to what the [sustainable] yields will be, not the demand. \u2026 We don\u2019t want to be asking for more than what the wells can actually produce.\u201d<\/p>\n\n\n\n
With regard to the supply from the Pearl Harbor aquifer sector that Wai\u02bbanae relies on, he noted that the Waipahu-Waiawa aquifer\u2019s sustainable yield is 104 million gallons a day and only about 60 mgd is being pumped. <\/p>\n\n\n\n
“There\u2019s unused sustainable yield there that may be affected by climate change,\u201d he said. The Ewa-Kunia aquifer sustainable yield, however, is predicted to decrease, he said.<\/p>\n\n\n\n
With yields for Makaha and Wai\u02bbanae also predicted to decrease, Usagawa suggested that bringing water in from outside is not a panacea. <\/p>\n\n\n\n
Meeting demand with whatever what sustainable yields are set must take into account the BWS system\u2019s limitation. <\/p>\n\n\n\n
\u201cWe can\u2019t get water all the way to Makaha. \u2026 If the straw is long enough, you can only blow so much. Nothing comes out the other end,\u201d he said, adding that the system can only take Pearl Harbor aquifer water as far as Wai\u02bbanae town.<\/p>\n\n\n\n
Addressing more broadly of system capacity and development on the island, commissioner Hannah Springer asked whether, for the BWS, water availability may \u201ccome in line ahead of land use.\u201d <\/p>\n\n\n\n
\u201cIt seems like we investigate water resources after commitments to develop land have been made. Using my water sensibility hat, I\u2019m not going to build a lo\u02bbi if there is no stream nearby. Are we inclined in that direction now?\u201d she asked.<\/p>\n\n\n\n
Usagawa replied that he looked at land use and water availability concurrently. <\/p>\n\n\n\n
\u201cThey go hand-in-hand,\u201d he said. \u201cYou cannot plan for the next big growth area until you know how much water we got. And we don\u2019t know how much water \u2026 we\u2019ll need in our system capacity. We can\u2019t plan for expanding that until we know how much the growth is. It\u2019s chicken and egg, but it\u2019s concurrent.\u201d<\/p>\n\n\n\n
He added that he hoped developers \u201chave the wherewithal to at least ask us what is it going to take and we can comment on a land use plan.” <\/p>\n\n\n\n
\u201cThis whole climate change layer and potential reducing of the sustainable yield of the aquifers because rainfall is decreasing, we have already told some of the large transit-oriented developments that we cannot confirm all the water you\u2019re projecting. So then it\u2019s a first come, first served, on our system on the remaining amount.\u201d<\/p>\n\n\n\n
He said the shutting down of wells as a result of contamination from the U.S. Navy\u2019s Red Hill fuel tanks exacerbates the problem. “Now there\u2019s less for \u02bbEwa and Wai\u02bbanae, if you start to reduce sustainable yield, you start to get to the point we don\u2019t have the capacity. It\u2019s thin now,\u201d he said.<\/p>\n\n\n\n
\u201cWe\u2019re trying to support growth but [developers] have to have an idea of how much water got. Otherwise, we\u2019ll just say, \u2019Not yet,\u2019\u201d he said.<\/p>\n\n\n\n
\u2014 Teresa Dawson<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" On May 20, the state Commission on Water Resource Management voted unanimously to accept a petition by the Honolulu Board of Water Supply to designate the Waiʻanae aquifer sector as a ground water management area. The area incudes the aquifers … Continued<\/a><\/p>\n","protected":false},"author":1,"featured_media":16405,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[540,28],"tags":[3],"class_list":["post-16673","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-august-2025","category-water","tag-teresa-dawson"],"_links":{"self":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts\/16673","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=16673"}],"version-history":[{"count":0,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts\/16673\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/media\/16405"}],"wp:attachment":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=16673"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=16673"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=16673"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}