Opinion ID: 2629221
Heading Depth: 2
Heading Rank: 1

Heading: The Commission's Decision Violated DHHL's Reservation Rights As Guaranteed By The HHCA, The Hawai`i Constitution, The Code, And The Public Trust Doctrine.

Text: The present appeal addresses an issue of first impression, namely, the extent to which a reservation of water precludes an applicant for a new water use permit from satisfying the conditions requisite to obtaining such permit, as set forth in HRS § 174C-49(a), see supra note 1. The crux of the appellants' contentions on appeal stem from (1) the Commission's decision that a reservation of water did not constitute an existing legal use for purposes of the Code and (2) the Commission's finding that DHHL's reservations were aquifer-specific and that, therefore, MR-Wai`ola's application for a water use permit in the Kamiloloa aquifer system could not interfere with DHHL's reservation in the Kualapu'u aquifer system as a matter of law. We address the foregoing issues at the outset because they are outcome-dispositive of many of the appellants' points of error.
The Ritte intervenors, with whom OHA and the Kahae intervenors join, contend that the Commission's conclusion that DHHL's reservations were aquifer-specific and, therefore, that MR-Wai`ola's proposed water use in the Kamiloloa aquifer system would not interfere with DHHL's reservation rights in the Kualapu'u aquifer system was arbitrary, capricious, and contrary to Hawai`i law. [24] More specifically, the Ritte intervenors assert that the concept of separate aquifer systems, upon which the Commission predicated its decision, was incongruous with the hydrological evidence adduced at the contested case hearing i.e., that the Kamiloloa and Kualapu'u aquifer systems were hydrologically connected and, thus, that a drawdown of water from one aquifer would, of necessity, affect the other. The Ritte intervenors posit that the Commission formulated the sixteen aquifers on Moloka'i based on topographical distinctions for administrative convenience and, in so doing, deprived DHHL of the effective use of its 2.905 mgd reservation in the Kualapu`u aquifer system, as guaranteed by HAR § 13-171-63, see supra note 13. The Commission responds that, although neither the HAR nor the Code expressly define the term reservation, the relevant sections that utilize the term imply that reservations are indeed aquifer-specific. The Commission argues that the HAR expressly entitle DHHL to a designated quantity of water in a particular aquifer and that, inasmuch as [a]ctual use of reserved water requires a water use permit, a reservation of water is almost [on] the same footing as another party's application for water. Similarly, MR-Wai'ola discounts the appellants' argument that, hydrologically speaking, the sixteen aquifers of Moloka'i are connected and, therefore, actually constitute a single overarching aquifer. In this regard, MR-Wai'ola contends that each aquifer has its own sustainable yield [25] of water and that the Code authorizes the Commission to establish each hydrologic unit [26] and sustainable yield through the adoption of the State Water Resources Protection Plan. As such, MR-Wai'ola maintains that, in order to change the boundaries of hydrologic units and sustainable yields, the Commission would have to conduct a separate rule-making process, and, therefore, that to accept the appellants' argument ( i.e., that the Kamiloloa and Kualapu'u aquifers are, in fact, a single aquifer) would circumvent the Hawai`i Administrative Procedures Act and rewrite rules without going through the proper process. Finally, MR-Wai'ola asserts that, assuming arguendo that the Kualapu'u and Kamiloloa aquifers were a single aquifer, the combined sustainable yields could nonetheless accommodate DHHL's 2.905 mgd reservation in addition to the permitted allocation of 655,928 gpd to MR-Wai`ola. Although we agree that the HAR denominate aquifer-specific reservations of water to DHHL, we hold that such a limitation for purposes of water resource management does not divest DHHL of its right to protect its reservation interests from interfering water uses in adjacent aquifers. Pursuant to HRS § 174C-5 (1993), [t]he general administration of the state water code shall rest with the commission on water resource management. Moreover, [t]he commission shall adopt and enforce such rules as may be necessary or convenient to administer the Code. HRS § 174C-8 (1993). Pursuant to the foregoing enabling statutes, the Commission adopted HAR § 13-170-2 (1996), [27] which mandates that the Commission formulate the Hawai`i water plan in order to protect, conserve, and manage the waters of the state. HAR § 13-170-2(c) further provides that, [i]n preparing the Hawai`i water plan[,] each county shall be divided into sections [ (aquifers) ] which shall conform as closely as practicable to hydrologic units and that [t]he Plan shall describe and inventory the ... [s]ustainable yield. See supra note 27. The HAR also require the counties, in developing their own water use and development plan, to utilize the hydrologic units designated statewide by the commission for the presentation of data and analyses. HAR § 13-170-32(a) (1996); see also HAR §§ 13-170-30 and 13-170-42 (1996). With respect to interpreting the HAR, [t]he general principles of construction which apply to statutes also apply to administrative rules. As in statutory construction, courts look first at an administrative rule's language. If an administrative rule's language is unambiguous, and its literal application is neither inconsistent with the policies of the statute the rule implements nor produces an absurd or unjust result, courts enforce the rule's plain meaning. International Bhd. of Elec. Workers, Local 1357 v. Hawaiian Tel. Co., 68 Haw. 316, 323, 713 P.2d 943, 950 (1986) (citations omitted). Moreover, an administrative agency's interpretation of its own rules is entitled to deference unless it is plainly erroneous or inconsistent with the underlying legislative purpose. Id. Lee v. Elbaum, 77 Hawai`i 446, 457, 887 P.2d 656, 667 (App.1993). Furthermore, insofar as an administrative hearings officer possesses expertise and experience in his or her particular field, the appellate court `should not substitute its own judgment for that of the agency[.]' Okada Trucking Co., Ltd. v. Board of Water Supply, 97 Hawai`i 450, 458, 40 P.3d 73, 81, reconsideration denied, 101 Hawai`i 233, 65 P.3d 180 (2002). In the present matter, HAR § 13-171-63, see supra note 13, expressly reserves 2.905 mgd of groundwater for DHHL in the Kualapu'u aquifer system. On its face, HAR § 13-171-63 is unambiguously aquifer-specific in that the Commission dedicated a precise quantity of water in a particular aquifer for an enumerated purpose. In promulgating HAR § 13-171-63, the Commission, using the best available information, see HAR § 13-170-2(c)(3) supra note 27, ascertained the sustainable yield in the Kualapu'u aquifer and designated a reservation of water in such quantity as was deemed necessary for purposes that were consistent with the use of Hawaiian home lands, pursuant to HHCA § 221 and HRS § 174C-101(a). See HAR § 13-171-60(b) (1996). That being the case, insofar as (1) the Commission, as the agency authorized to administer the Code, determines the contents of the Hawai`i water plan, which includes the designation of hydrologic units and sustainable yields, and (2) the Commission's interpretation of its own rules is entitled to `deference unless it is plainly erroneous or inconsistent with the underlying legislative purpose,' Lee, 77 Hawai`i at 457, 887 P.2d at 667, we believe that it is within the Commission's authority to limit reservations of water to specific aquifers. Moreover, assuming arguendo that the Commission's designation of the sixteen aquifers on Moloka`i was strictly topographical i.e., without consideration of any sub-surface geological barriers that divide the bodies of underground waterwe do not believe that this court should redefine what constitutes an aquifer, or DHHL's aquifer-specific reservations for that matter, based purely on the hydrological data on the record before us. Quite simply, the Commission possesses the expertise and experience in its particular field and, thus, is in a better position to amend the HAR if necessary. Cf. Ko`olau Agricultural Co., Ltd. v. Commission On Water Resource Management, 83 Hawai`i 484, 493, 927 P.2d 1367, 1376 (1996) (The Commission, by virtue of its agency expertise, is certainly in a better position than the courts to evaluate scientific investigations and research to determine whether a water resource may be threatened by existing or proposed withdrawals and diversions of water. (Internal quotation marks omitted.)). Thus, in light of the foregoing, the Commission's designation of aquifer-specific reservations, as set forth in HAR §§ 13-171-61 through 63, although based in part on topographical distinctions, was not arbitrary, capricious, or contrary to law. Notwithstanding the foregoing, HAR § 13-171-63 does not divest DHHL of its statutory and public trust rights to protect and preserve its reservation interests from interfering uses in adjacent aquifers. See HRS § 174C-49(a)(7), supra note 1 ([T]he applicant must establish that the proposed use of water ... [w]ill not interfere with the rights of the [DHHL] as provided in section 221 of the [HHCA].); HRS § 174C-49(e), supra note 1 (All permits issued by the commission shall be subject to the rights of the [DHHL] as provided in section 221 of the [HHCA], whether or not the condition is explicitly stated in the permit.); HRS § 174C-53(b), supra note 5 ([T]he commission need consider only those objections filed by a person who has some property interest in any land within the hydrologic unit ... or who will be directly and immediately affected by the water use proposed in the application....); HRS § 174C-101(a), supra note 4 (Decisions of the commission on water resource management ... shall, to the extent applicable and consistent with other legal requirements and authority, incorporate and protect adequate reserves of water for current and foreseeable development and use of Hawaiian home lands as set forth in section 221 of the [HHCA].). To hold otherwise would cripple DHHL's ability to contest proposed uses in adjacent aquifers that could significantly diminish its ability to utilize its reservations in the future simply because the proposed use was outside the Kualapu'u aquifer; such an interpretation defies not only legal but also scientific logic. That being the case, MR-Wai`ola had the burden of establishing, pursuant to HRS § 174C-49(a)(7), that the proposed use would not interfere with DHHL's 2.905 reservation of water in the Kualapu'u aquifer system. Likewise, the Commission was duty bound to hold MR-Wai'ola to its burden under the Code and the public trust doctrine. See further discussion infra in section III.A.3.c.
One of the conditions requisite to obtaining a water use permit, pursuant to HRS § 174C-49(a), is that the proposed use not interfere with any existing legal use of water. See HRS § 174C-49(a)(3) supra note 1 (emphases added). The appellants presuppose, or otherwise urge this court to hold, that a reservation of water constitutes an existing legal use, for purposes of HRS § 174C-49(a)(3). The appellants essentially contend that HHCA §§ 220 and 221 grant to DHHL a first call right to all government-owned waters and that the 1991 amendments to the Codenamely, HRS §§ 174C-49 and 174C-101incorporated DHHL's priority water rights under the HHCA by mandating that the State reserve water for DHHL's water needs and protect DHHL's reservations against competing interests. The appellants assert that the Commission erred in concluding (1) that DHHL's reservation in the Kualapu'u aquifer system was not an existing legal use and (2) that MR-Wai'ola's proposed water use in the Kamiloloa aquifer system would not affect DHHL's reservation rights in the Kualapu`u aquifer system. The appellants maintain that the Commission has a duty to set aside adequate reservations to meet DHHL's current and foreseeable needs and that DHHL's rights take priority over other government and private interests, all of which requires the Commission to insure that other users do not interfere with DHHL's reservations. For its part, DHHL argues that the legislature amended the Code in order to grant DHHL an `absolute' priority to water by (1) requiring applicants for new water use permits to establish that the proposed use would not interfere with DHHL's rights, see HRS § 174C-49(a)(7), supra note 1, (2) mandating that existing users be subject to DHHL's rights under HHCA § 221, see HRS § 174C-49(e), and (3) providing that the Commission incorporate and protect adequate reserves of water for current and foreseeable development and use of Hawaiian home lands as set forth in section 221 of the [HHCA], see HRS § 174C-101(a). In addition, DHHL contends that the increased salinity in its existing wells in Kualapu'u, the Commission's rejection of DHHL's application to pump additional water from its existing wells, and MR-Wai`ola's proposed well, in combination, will inevitably force DHHL (1) to decrease its permitted uses, (2) forego exercising its reservation rights from its existing wells in Kualapu'u, and (3) acquire alternative water sources that are both geographically and economically undesirable. Thus, the appellants posit that the only effective way to give meaning to a reservation is not to grant other uses subject to recall, but to actually bar use which draws down any of DHHL's reserved water. The Commission counters that, inasmuch as HRS § 174C-49(d) separately denominates existing legal uses and reservations, it would be fallacious to interpret a reservation as coextensive with an existing legal use. In addition, the Commission reiterates its argument that reservations of water are aquifer-specific and that, therefore, the proposed use in the Kamiloloa aquifer system would not interfere with DHHL's existing uses or reservation rights in the Kualapu'u aquifer system. We agree with the Commission that, pursuant to the plain language of HRS § 174C-49(d) and HAR § 13-171-63, a reservation of water does not constitute an existing legal use for purposes of HRS § 174C-49(a)(3). At the outset, we note that the term reservation is nowhere defined in the HRS or the HAR. Both the HRS and the HAR, however, expressly refer to a reservation of water. See HRS § 174C-49(d) and HAR §§ 13-171-61 through 63 (designating reservations of water to DHHL in certain WMAs on O`ahu and Moloka`i). Specifically, HRS § 174C-49(d), see supra note 1, provides that [t]he commission, by rule, may reserve water in such locations and quantities... as in its judgment may be necessary. Such reservations shall be subject to periodic review and revision in light of changed conditions; provided that all presently existing legal uses of water shall be protected. (Emphases added.) Moreover, HAR § 13-171-63 states that DHHL's 2.905 mgd reservation of groundwater from state lands in the Kualapu'u aquifer system shall be in excess of the existing uses of water on Hawaiian home lands[.] (Emphasis added.) The foregoing language plainly and unambiguously distinguishes a reservation from an existing legal use, and, accordingly, it is inconceivable that the legislature intended that the terms be coextensive with each other. We therefore hold that a reservation of water does not constitute an existing legal use within the meaning of HRS § 174C-49(a)(3). Although we ground our holding in the plain language of HRS § 174C-49(d) and HAR § 13-171-63, we nonetheless note that, to read the Code as defining a reservation as an existing legal use would also render HRS § 174C-49(a)(7), which expressly addresses DHHL's rights under the HHCA, superfluous. See supra note 1. HRS § 174C-49(a)(7) requires that an applicant for a water use permit establish that the proposed use [w]ill not interfere with the rights of the [DHHL] as provided in Section 221 of the [HHCA]. That being the case, insofar as DHHL's right to reservations of sufficient water ... for current and foreseeable domestic, stock water, aquaculture, and irrigation activities stem from HHCA § 220, HRS § 174C-49(a)(7), and not HRS § 174C-49(a)(3), protects DHHL's reservation rights in the present matter. See Coon v. City and County of Honolulu, 98 Hawai`i 233, 250, 47 P.3d 348, 365 (2002) (`Our rules of statutory construction requires us to reject an interpretation of [a] statute ... that renders any part of the statutory language a nullity.') (quoting Potter v. Hawai`i Newspaper Agency, 89 Hawai`i 411, 423-24, 974 P.2d 51, 63-64 (1999) (citations omitted) (bracket in original)); Keliipuleole v. Wilson, 85 Hawai`i 217, 221, 941 P.2d 300, 304 (1997) (`[C]ourts are bound to give effect to all parts of a statute, and that no clause, sentence, or word shall be construed as superfluous, void, or insignificant if a construction can be legitimately found which will give force to and preserve all words of the statute.') (Citations omitted.). Thus, existing legal uses and reservations of water constitute distinct interests in the State's water resources, which HRS § 174C-49(a) protects separately against interference by competing interests.
The appellants assert that the Commission's decision violated the State's constitutional public trust duty to honor and carry out the terms and conditions of the HHCA. The appellants essentially contend that DHHL has an absolute or first call priority to all government-owned waters. More specifically, the appellants argue (1) that DHHL's priority water rights stem from HHCA §§ 220 and 221, the Hawai`i Constitution, which adopted the HHCA as a provision of the state Constitution, and HRS §§ 174C-49, 174C-101, and 174C-31 (1993) and (2) that the legislature intended to insure that Hawaiian homelands (a) received adequate water for future uses, (b) not be prejudiced by DHHL's delay in developing infrastructure for Hawaiian homestead lands, and (c) not be prejudiced by other private land owners' attempts to exploit water resources without regard to the present and future needs of DHHL. Put simply, the appellants maintain that the Commission is subject to a duty to set aside adequate reservations of water to meet DHHL's current and future needs and to insure that other users do not interfere with DHHL's reservations of water, all of which takes priority over other government and private interests. As we mentioned supra in section III.A.2, the appellants posit that MR-Wai'ola's proposed well would adversely affect DHHL's section 221 first call rights to water from government lands and DHHL's ability to exercise its 2.905 mgd reservation in the Kualapu'u aquifer system in light of the fact that the Commission had previously rejected DHHL's request to pump additional water from its existing wells in Kualapu'u due to rising salinity, which, in turn, would inevitably require DHHL to drill a new well in close proximity to MR-Wai`ola's proposed well site in Kamiloloa. The appellants argue that if DHHL were subject to the impairment of its ability to withdraw water from its reservation by virtue of intervening water use permits granted prior to DHHL obtaining its own water use permit, then DHHL's reservation would be completely illusory, affording no rights beyond those already enjoyed by persons without existing reservations. [28] The Commission counters that its decision upholds the public trust doctrine, the Commission having evaluated the water available, evaluated the competing interests, and... accommodate[d] all interests in the Kamiloloa aquifer. In particular, the Commission maintains that its decision accommodated all of the parties' interests by allocating only one-half of the quantity of water that MR-Wai'ola had requested and keeping all allocations from the Kamiloloa aquifer system significantly below the sustainable yield without adversely affecting the nearshore environment. The Commission asserts that it considered DHHL's argument that it needed more water from the Kualapu'u aquifer and recognized that DHHL had a reservation in Kualapu'u for 2.905 mgd. The Commission, however, argues that DHHL was unable to demonstrate additional future needs of water distinct from its reservation in Kualapu`u and that there was evidence that DHHL could secure other sources of water for future development if necessary. As such, the Commission contends that, inasmuch as DHHL's evidence regarding its future needs was speculative, it correctly found that DHHL was able to use its reservation in the Kualapu'u aquifer and that the proposed use would not interfere with DHHL's reservation rights protected by the HHCA.
In Waiahole, this court held that the public trust doctrine applied to all water resources, unlimited by any surface-ground distinction. 94 Hawai`i at 133-35, 9 P.3d at 445-47 (affirming Robinson, 65 Haw. at 674, 658 P.2d at 310, wherein the court stated that a public trust was imposed upon all the waters of the kingdom). In so doing, this court traced the historical development of the public trust doctrine in Hawai`i and reasoned therefrom that article XI, sections 1 and 7 of the Hawai`i Constitution, see supra note 3, adopted the public trust doctrine as a fundamental principle of constitutional law in Hawai`i and that the legislature, pursuant to the constitutional mandate of article XI, section 7, incorporated public trust principles into the Code. Id. at 130-32, 9 P.3d at 443-45. Moreover, in holding that the Code does not supplant the protections of the public trust doctrine, this court recognized that [e]ven with the enactment and any future development of the Code, the doctrine continues to inform the Code's interpretation, define its permissible `outer limits,' and justify its existence. Id. at 133, 9 P.3d at 445. In addressing the substance of the state water resources trust, this court identified three valid trust purposes, which the Commission was duty-bound to protect against competing interests in the State's water resources: (1) water resource protection, which includes the maintenance of waters in their natural state as a distinct use and disposes of any portrayal of retention of waters in their natural state as `waste'; (2) domestic use protection, particularly drinking water; and (3) the exercise of native Hawaiian and traditional and customary rights. Id. at 136-38, 9 P.3d at 448-50. This court held, however, that, while the state water resources trust acknowledges that private use for `economic development' may produce important public benefits and that such benefits must figure into any balancing of competing interests in water, private commercial use is not a public trust purpose. Id. at 138, 9 P.3d at 450. This court opined that if the public trust is to retain any meaning and effect, it must recognize enduring public rights in trust resources separate from, and superior to, the prevailing private interests in the resources at any given time. Id. (Emphasis added.) Consequently, this court affirmed the Commission's conclusion that the public trust doctrine effectively prescribes a `higher level of scrutiny' for private commercial uses ... [and] that the burden ultimately lies with those seeking or approving such uses to justify them in light of the purposes protected by the trust. Id. at 142, 9 P.3d at 454. This court has described the public trust relating to water resources as the authority and duty to maintain the purity and flow of our waters for future generations and to assure that the waters of our land are put to reasonable and beneficial uses. Id. at 674, 658 P.2d at 310 (emphases added). Similarly, article XI, section 1 of the Hawai`i Constitution requires the state both to protect natural resources and to promote their use and development. The state water resources trust thus embodies a dual mandate of 1) protection and 2) maximum reasonable and beneficial use. The mandate of protection coincides with the traditional notion of the public trust developed with respect to navigable and tidal waters. As commonly understood, the trust protects public waters and submerged lands against irrevocable transfer to private parties, see, e.g., Illinois Central [Railroad Co. v. Illinois], [146 U.S. 387, 452-53, 13 S.Ct. 110, 36 L.Ed. 1018 (1892),] [ ] or substantial impairment, whether for private or public purposes, see, e.g., State v. Public Serv. Comm'n, [275 Wis. 112, 81 N.W.2d 71, 74 (1957) ] [ ]. In this jurisdiction, our decisions in McBryde [ Sugar Co., Ltd. v. Robinson, 54 Haw. 174, 504 P.2d 1330 (1973) ] and its progeny and the plain meaning and history of the term protection [footnote omitted] in article XI, section 1 and article XI, section 7 establish that the state has a comparable duty to ensure the continued availability and existence of its water resources for present and future generations. Id. at 138-39, 9 P.3d at 450-51. In Hawai`i, the water resources trust also encompasses a duty to promote the reasonable and beneficial use of water resources in order to maximize their social and economic benefits to the people of this state. Id.; see also article XI, section 1 of the Hawai`i Constitution, supra note 3 (For the benefit of present and future generations, the State ... shall promote the development and utilization of these [water] resources in a manner consistent with their conservation and in furtherance of the self-sufficiency of the State.). As we have mentioned, however, maximizing the water resource's social and economic benefits includes the protection of the resource in its natural state. Thus, unlike other jurisdictions, this court noted that the object is not maximum consumptive use, but rather the most equitable, reasonable, and beneficial allocation of state water resources, with full recognition that resource protection also constitutes `use.' Id. at 140, 9 P.3d at 452. Finally, with respect to balancing the foregoing mandates of the state water resources trust, this court held that the trust embodies the following fundamental principles. Id. at 141-43, 9 P.3d at 453-55. First, the state has both the authority and duty to preserve the rights of present and future generations in the waters of the state, which, in effect, precludes any grant or assertion of vested rights to use water to the detriment of a public trust purpose. Id. This authority empowers the state to revisit prior diversions and allocations, even those made with due consideration of their effect on the public trust. Id. at 141, 9 P.3d at 453. Second, [t]he state [ ] bears an `affirmative duty to take the public trust into account in the planning and allocation of water resources, and to protect public trust uses whenever feasible.' Id. at 141, 9 P.3d at 453 (quoting National Audubon Society v. Superior Court of Alpine County, 33 Cal.3d 419, 189 Cal.Rptr. 346, 658 P.2d 709, 728, cert. denied, 464 U.S. 977, 104 S.Ct. 413, 78 L.Ed.2d 351 (U.S.Cal.1983)) (emphasis in original) (footnote omitted). Third, there are no absolute priorities between broad categories of [trust] uses under the water resources trust, precisely because all public trust purposes must be protected; thus, the Commission must weigh competing public and private water uses on a case-by-case basis[.] Id. at 142, 9 P.3d at 454. That being the case, the Commission, as the primary guardian of public rights under the trust, must take the initiative in considering, protecting, and advancing public rights in the resource at every stage of the planning and decisionmaking process. Id. at 143, 9 P.3d at 455. In sum, the state may compromise public rights in the resource pursuant only to a decision made with a level of openness, diligence, and foresight commensurate with the high priority these rights command under the laws of our state. Id.
We have consistently recognized the heightened duty of care owed to the native Hawaiians. See PASH, 79 Hawai`i at 451, 903 P.2d at 1272 (holding that the Hawai`i Planning Commission must protect the reasonable exercise of customary and traditional rights of the native Hawaiians); Pele Defense Fund v. Paty, 73 Haw. 578, 620-21, 837 P.2d 1247, 1272 (1992) (holding that native Hawaiian rights protected by article XII, section 7 may extend beyond the ahupua`a in which a native Hawaiian resides); Kalipi v. Hawaiian Trust Company, Ltd., 66 Haw. 1, 7-8, 656 P.2d 745, 749 (1982) (interpreting HRS § 7-1 to assure that lawful occupants of an ahupua[`]a may, for the purposes of practicing native Hawaiian customs and traditions, enter undeveloped lands within the ahupua[`]a to gather those items enumerated in the statute); Ahuna v. Department of Hawaiian Home Lands, 64 Haw. 327, 338, 640 P.2d 1161, 1168 (1982) (holding that DHHL assumed the obligation to implement the state's fiduciary duty under the HHCA on behalf of eligible native Hawaiians). Native Hawaiians' water rights are no exception. Waiahole, 94 Hawai`i at 137, 9 P.3d at 449 (upholding the exercise of native Hawaiian and traditional and customary rights as a public trust purpose). Our analysis in Waiahole, however, begs the question whether a reservation of water constitutes a public trust purpose with respect to the state's continuing trust obligation to ensure the continued availability and existence of its water resources for present and future generations. 94 Hawai`i at 139, 9 P.3d at 451. We answer the foregoing in the affirmative and hold that, pursuant to article XI, sections 1 and 7 of the Hawai`i Constitution, HHCA § 220(d), and HRS § 174C-101(a), a reservation of water constitutes a public trust purpose. As discussed supra in section III.A.3.a, the Commission bears a duty to protect the continued availability of water resources in balancing the competing interests for a water use permit. In addition, HHCA § 220(d), see supra note 2, expressly requires that sufficient water shall be reserved for current and foreseeable domestic, stock water, aquaculture, and irrigation activities on tracts leased to native Hawaiians.... Moreover, HRS § 174C-101(a) states in relevant part that [d]ecisions of the commission on water resource management relating to the planning for, regulation, management, and conservation of water resources in the State shall ... incorporate and protect adequate reserves of water for current and foreseeable development and use of Hawaiian home lands as set forth in section 221 of [HHCA]. (Emphasis added.) See also HRS § 174C-49(e), supra note 1 (All permits issued by the commission shall be subject to the rights of the [DHHL] as provided in section 221 of the [HHCA], whether or not the condition is explicitly stated in the permit.). Inasmuch as a reservation of water is an essential mechanism by which to effectuate the State's public trust duty to ensure the continued availability and existence of its water resources for present and future generations, see Waiahole, 94 Hawai`i at 139, 9 P.3d at 451, we hold that DHHL's reservations of water throughout the State are entitled to the full panoply of constitutional protections afforded the other public trust purposes enunciated by this court in Waiahole. To hold otherwise would undermine the public trust doctrine, which is a state constitutional doctrine, and the relevant policy declarations set forth in the Code. See HRS § 174C-101(a), supra note 4 (Traditional and customary rights of ahupua'a tenants ... shall not be abridged or denied by this chapter.); HRS § 174C-2(c), supra note 21 ([A]dequate provision shall be made for ... the protection and procreation of fish and wildlife, the maintenance of proper ecological balance and scenic beauty, and the preservation and enhancement of waters of the State for municipal uses, public recreation, public water supply, agriculture, and navigation....). [29] (c) Although the Commission discharged its public trust duty to protect DHHL's existing legal uses in the Kualapu'u aquifer, it failed adequately to discharge its duty to protect DHHL's reservation in the Kualapu'u aquifer. In light of the foregoing, we now address whether the Commission discharged its duty to protect DHHL's reservation rights in the Kualapu'u aquifer system against competing interests in the state's water resources trust. To begin, we recognize that, generally, agency decisions affecting public trust resources carry a presumption of validity. Wai&amacr;hole, 94 Hawai`i at 143, 9 P.3d at 455. Moreover, [t]he presumption is particularly significant where the applicant challenges a substantial decision within the agency's expertise as `clearly erroneous,' HRS § 91-14(g)(5), `arbitrary,capricious,' or an `abuse of discretion,' HRS § 91-14(g)(6). Id. However, the foregoing presumption of validity presupposes that the agency has grounded its decision in reasonably clear FOFs and COLs. In the present matter, the record is void of a single FOF regarding whether MR-Wai`ola established that the proposed use would interfere with DHHL's reservation in the Kualapu'u aquifer as mandated by the Code. The Commission concluded that, because (1) HAR § 13-171-63 granted DHHL an aquifer-specific reservation in the Kualapu`u aquifer and (2) the proposed use was located in the Kamiloloa aquifer, MR-Wai'ola need not meet its burden with respect to DHHL's reservation. As discussed supra in section III.A.1, the aquifer-specific nature of DHHL's reservation, as set forth in the HAR, does not eliminate MR-Wai`ola's burden under HRS § 174C-49(a)(7), and, consequently, the Commission was duty bound to hold MR-Wai`ola to its burden. Inasmuch as the Commission failed to render the requisite FOFs and COLs with respect to whether MR-Wai`ola had satisfied its burden as mandated by the Code, it violated its public trust duty to protect DHHL's reservation rights under the HHCA, the Code, the Hawai`i Constitution, and the public trust doctrine in balancing the various competing interests in the state water resources trust. Accordingly, we vacate and remand for the entry of further FOFs and COLs on the matter. Notwithstanding the foregoing violation of the public trust doctrine, we believe that the Commission upheld its public trust obligation to protect DHHL's existing legal uses in Kualapu'u i.e., DHHL's existing wellsagainst the competing private commercial use proposed by MR-Wai'ola. As this court observed in Waiahole with respect to offstream uses, article XI, section 1 of the Hawai`i Constitution mandates that all water uses, public or private, promote the best economic and social interests of the people of this state. 94 Hawai`i at 141, 9 P.3d at 453. Moreover, as discussed supra in section III.A.3.a, private commercial use for economic development, although not a cognizable trust objective, may produce important public benefits and ... must figure into any balancing of competing interests of water. Id. at 138, 9 P.3d at 450. Unquestionably, our decision in Waiahole does not preclude the controlled development of water resources for private commercial use. Id. at 141, 9 P.3d at 453 (The public has a definite interest in the development and use of water resources for various reasonable and beneficial public and private offstream purposes[.] (Emphasis added.)). Instead, Waiahole ensures (1) that any balancing between public and private purposes begin with a presumption in favor of public use, access, and enjoyment, id. at 142, 9 P.3d at 454, and (2) that the planning and allocation of water resources for purposes of economic development must account for the public trust and protect public trust uses to the extent feasible. Id. (recognizing that the public trust establishes use consistent with trust purposes as the norm or `default' condition). Consequently, we stated that reason and necessity dictate that the public trust may have to accommodate offstream diversions inconsistent with the mandate of protection, to the unavoidable impairment of public instream uses and values. Id. at 141, 9 P.3d at 453. The Commission, however, owes a duty to consider the cumulative impact of existing and proposed diversions on trust purposes and to implement reasonable measures to mitigate this impact, including the use of alternative sources. Id. at 143, 9 P.3d at 455. In the present matter, the Commission clearly addressed the potential impact of MR-Wai'ola's proposed water use in the Kamiloloa aquifer system on DHHL's existing wells in the Kualapu'u aquifer system. First, the Commission considered two hydrological studies in rendering its FOFs and COLS. In particular, the McNulty Model (proffered by MR-Wai`ola) predicted that the impact of pumping 1.25 mgd from the proposed well in Kamiloloa will result in water level declines of 0.17 to 0.32 feet at the existing Kualapu'u well field with [t]he largest impact ... at the nearest well in Kakalahale. Accordingly, the Commission found that the [w]ater level declines at the levels predicted by the McNulty Model would have no measurable effect on the quality or quantity of water drawn from existing wells  in Kualapu`u. (Emphasis added.) The USGS Model, the study proffered by DHHL, predicted that pumping 1.326 mgd from the proposed well in Kamiloloa (0.076 mgd more than the amount requested by MR-Wai'ola) would result in a drawdown greater than 0.1 feet and less than 0.5 feet and that [s]uch change is likely to be less than normal seasonal fluctuations of the groundwater level and of the same order of magnitude of normal semi-diurnal water level fluctuations created by varying barometric pressure. In other words, the impact is relatively small.  (Emphasis added.) Second, the Commission granted MR-Wai`ola a water use permit for only 655,928 gpd, approximately one-half of the requested quantity, thereby diminishing the foregoing predictions with respect to water-level declines in Kualapu'u, and only for the proposed future uses that were consistent with state and county general plans and land use designations and county land use plans and policies. Finally, in recognition of the importance and need for long-range planning for the efficient and effective use of water, the Commission's decision proposed a municipal reservation in the Kamiloloa aquifer system, which would not be limited to any one user but would be set up for municipal uses as defined in the Water Code. Thus, to the extent that the Commission's decision compromised DHHL's existing wells in the Kualapu'u aquifer system, we believe that the Commission did so with a level of openness, diligence, and foresight commensurate with the high priority these rights command under the laws of our state. Waiahole, 94 Hawai`i at 143, 9 P.3d at 455.