This case involves a dispute over the Tacoma-Pierce County Board of Health’s resolution requiring municipal water districts and certain private water purveyors to fluoridate their water. Four sets of plaintiffs filed separate lawsuits against the Tacoma-Pierce County Board of Health (the Board) and the Tacoma-Pierce County Health Department (the Department), challenging the resolution’s validity. The trial court granted summary judgment in favor of the Board. We reverse and hold that the resolution conflicts with RCW 57.08.012, which gives water districts the power to control the content of their water systems and, with that power, the authority to fluoridate their water.
FACTUAL AND PROCEDURAL HISTORY
On October 2, 2002, the Board adopted Resolution No. 2002-3366.A-2, entitled, “Regulation Requiring Fluoridation of Drinking Water in Pierce County Water Systems Serving 5,000 or More People.” Br. of Appellants at 2. Essentially, the resolution purports to solve the dental caries problem in Pierce County by requiring that certain water systems be fluoridated by January 1, 2004. The resolution also imposes a penalty of up to $250 per day if water purveyors do not comply with the mandate’s implementation. The Board would provide funding to water *431purveyors in order to offset the costs of implementing the fluoridation mandate if they signed letters of intent or began implementation by December 31, 2002.
Four sets of plaintiffs filed separate lawsuits against the Board and Department challenging the resolution’s validity. The plaintiffs were (1) five private water companies called Parkland Light & Water Co., Fruitland Mutual Water Co., Mountain View-Edgewater Co., Summit Water & Supply Co., and Spanaway Water Co. (Parkland Light); (2) Lakewood Water District (Lakewood); (3) Citizens Opposing Fluoridation in Pierce County (Citizens); and (4) the City of Bonney Lake (Bonney Lake).
On December 20, 2002, the trial court consolidated the claims. The trial court set an expedited briefing and hearing schedule, and the parties exchanged cross-motions for summary judgment.
On February 19, 2003, the trial court entered an order granting the Board’s motion for summary judgment and denying the plaintiffs’ cross-motions for summary judgment.
Three of the four plaintiffs appealed the order.1 Parkland and Bonney Lake sought timely review of the order with Division Two of the Court of Appeals, while Lakewood sought an emergency stay and direct review with this court.2 We accepted review and applied the stay to Lakewood.3
The plaintiffs present four errors for review. Specifically, the private water companies allege that (1) the Board does not have the police power to exercise the resolution, (2) the resolution imposes an illegal tax in kind, and (3) the resolution violates their due process rights; and Bonney *432Lake alleges that (4) it has standing to assert forced medical treatment and voting rights violation claims on behalf of its citizens. We hold that the resolution irreconcilably conflicts with the statutes governing the authority of water districts. See RCW 57.08.005; RCW 57.08.012, infra.
ANALYSIS
On appeal from summary judgment, we engage in the same inquiry as the trial court. RAP 9.12. After considering all evidence and reasonable inferences in the light most favorable to the nonmoving party, summary judgment is appropriate if there is no genuine issue as to any material fact and the moving party is entitled to judgment as a matter of law. CR 56(c).
Interpreting a statute presents a question of law subject to de novo review. Waste Mgmt. of Seattle, Inc. v. Utils. & Transp. Comm’n, 123 Wn.2d 621, 627, 869 P.2d 1034 (1994). When interpreting a statute, our fundamental duty is to ascertain and fulfill legislative intent. However, if a statute is clear, it is not subject to judicial construction and its meaning is to be derived from the statute itself.
Under RCW 57.08.012, water districts are given the statutory authority to decide whether to fluoridate their water systems. RCW 57.08.012 specifically states that:
[a] water district by a majority vote of its board of commissioners may fluoridate the water supply system of the water district. The commissioners may cause the proposition of fluoridation of the water supply to be submitted to the electors of the water district at any general election or special election to be called for the purpose of voting on the proposition. The proposition must be approved by a majority of the electors voting on the proposition to become effective.
This section expressly provides that water districts have the authority to decide whether to fluoridate their water systems.
The issue we must resolve, then, is whether the Board’s resolution conflicts with the statutes governing the water *433districts’ specifically delegated discretionary authority by ordering fluoridation.
Local boards of health supervise all matters pertaining to the preservation of the life and health of the people within its jurisdiction. RCW 70.05.060. A Board’s statutory authority gives it the power to “[e]nact such local rules and regulations as are necessary in order to preserve, promote and improve the public health and provide for the enforcement thereof.” RCW 70.05.060(3).
These broad powers do not authorize the Board to act in areas where the legislature has made a more specific delegation of authority to another agency. For instance, where the Board’s action usurps specifically delegated statutory authority, a conflict can arise between the actions of one agency that negates the more specific statutory authority of another. If that occurs, the more specific statutory delegation of authority controls.
This court most recently considered whether a local regulation was invalid on grounds of conflict in HJS Development, Inc. v. Pierce County, 148 Wn.2d 451, 61 P.3d 1141 (2003). In HJS, we recognized and applied analytical framework for determining when a conflict occurs. We concluded that a local regulation conflicts with a statute when it “permits what is forbidden by state law or prohibits what state law permits.” HJS, 148 Wn.2d at 482 (citing Rabon v. City of Seattle, 135 Wn.2d 278, 292, 957 P.2d 621 (1998)). In other words, when two provisions are contradictory they cannot coexist. No conflict will be found, however, if the provisions can be harmonized. HJS, 148 Wn.2d at 482 (citing Heinsma v. City of Vancouver, 144 Wn.2d 556, 29 P.3d 709 (2001)).
In this case, we hold that the Board’s resolution irreconcilably conflicts with the authority granted to water districts under RCW 57.08.012, and the two cannot be harmonized. Essentially, the Board’s resolution is a local regulation that prohibits what state law permits: the ability of water districts to regulate the content and supply of their water systems expressly granted to them by statute. The *434resolution ordering fluoridation takes away any decision-making power from water districts with respect to the content of their water systems, and the express statutory authority granted to water districts pursuant to RCW 57.08.012 would be rendered meaningless. The purpose of the statute is to give water districts, not the Board, the authority over water fluoridation.
Here, the resolution is invalid as applied to Lakewood because it does not allow the water district to decide the issue of whether to fluoridate its water systems as provided for in RCW 57.08.012. No majority vote of the commissioners takes place. No vote of the electors (water users) within the water district takes place. The resolution deprives Lakewood of its specific statutory power and discretion provided under RCW 57.08.012.
The resolution is also invalid and ineffective as applied to the private water companies (Parkland Light). A local regulation that conflicts with state law fails in its entirety. See Adams v. Thurston County, 70 Wn. App. 471, 482, 855 P.2d 284 (1993) (holding that a county ordinance conflicted with state laws and was invalid as applied to all citizens); see also Employco Pers. Servs., Inc. v. City of Seattle, 117 Wn.2d 606, 618, 817 P.2d 1373 (1991) (holding that an entire ordinance which gave the city of Seattle blanket immunity from liability for damages for loss of electrical services was void because it conflicted with state statutes authorizing suits against utilities and permitting recovery of damages for negligently caused losses).
We lend further support for this conclusion by the fact that article XI, section 11 of the Washington State Constitution prohibits a local regulation from conflicting with a general law of the state. This means that when a local regulation conflicts with a state statute, we will invalidate the regulation. Because we conclude that an irreconcilable conflict exits, the Board’s resolution fails in its entirety and cannot be enforced against any party to the present suit. Thus, we need not decide any of the other issues raised by the parties in this case.
*435We reverse the trial court’s decision.
Alexander, C.J., and Madsen, Sanders, Chambers, and Owens, JJ., concur.
Citizens did not appeal.
The Board and Department joined in the request for direct review, and the private water companies did not object.
Before Lakewood filed its motion for an emergency stay, the commissioner of the Court of Appeals granted the same motion pending before that court. After the case was consolidated and transferred to this court, we extended the stay to include Lakewood. Commissioner’s Ruling (Mar. 19, 2003).