The issue in this case is whether the Director of the Division of State Lands had authority to issue an estuarian land fill permit. The Court of Appeals held that the Director lacked authority to issue the permit, 34 Or App 853, 581 P2d 520 (1978). This court granted the Director’s petition for review.
Pursuant to Oregon’s fill and removal law, ORS 541.605 to 541.665, the City of North Bend filed with the Division of State Lands an application for a permit to fill 32 acres of Coos Bay for the purpose of extending a runway at its municipal airport. The permit was granted and respondents, as persons claiming to be adversely affected by the proposed fill, requested a contested hearing. Following the hearing, the Director granted the application on the condition that the City mitigate the loss of estuarial resources by removing an old spoil island adjacent the permitted fill. Respondents sought judicial review and the Court of Appeals reversed, holding that the order was inconsistent with the Division’s administrative rule requiring that landfill projects be for a water-related purpose. Morse v. Division of State Lands, 31 Or App 1309,572 P2d 1075 (1977), rev. denied, 281 Or 431 (1978). The parties are in agreement that the airport extension is not for a water-related use.
Thereafter, the Director, by temporary rule, removed from the administrative regulations of the Division the requirement that fills be for a water-related activity.1 The City then renewed its application for the fill and, following a hearing on the permit *200in which the respondents participated, the Director issued a final order granting the renewed application. The testimony was largely that which had been taken pursuant to the previous application, and certain of the findings of fact made upon the first application were incorporated in the findings upon the second application. The Director found that the fill would reduce the water surface area and tidal prism of the Coos Bay estuary, that it would displace clams as well as other organisms and would eliminate some casual navigation of the recreational kind.
In an attempt to mitigate the harm to the estuary caused by the fill, the Director ordered the City to return certain diked submersible lands to the tidal influence rather than requiring a removal of the spoil island as directed on the first application. Respondents again appealed and the Court of Appeals held that the permit was beyond the authority of the Director because the public trust doctrine was intended to be incorporated into the statute and that the doctrine prohibited fills for non water-related uses. The opinion left open the question of whether the legislature has authority to modify the public trust doctrine. We granted review.
We agree that it is unnecessary to decide whether the legislature has authority to impinge upon the public trust doctrine but for a different reason than that given by the Court of Appeals. Contrary to that of the Court of Appeals, our conclusion is that the doctrine does not prohibit other than water-related uses in situations like the present one. Limitation *201upon the power of the state to permit alienation of the use of its waters is discussed in Shively v. Bowlby; 152 US 1, 14 S Ct 548, 38 L Ed 331 (1894), and Illinois Central Railroad v. Illinois, 146 US 387, 13 S Ct 110, 36 L Ed 1018 (1892). Illinois Central, which is considered to be the bellwether case, involved a situation in which the City of Chicago and the State of Illinois had granted the right to the railroad to the bed of Lake Michigan for an area a mile in length along the shore and a mile out into the lake, which encompassed substantially the entire lake bed available for the harbor of the City of Chicago. Because of the public interest, the jus publicum, in the use of the waters, the court held that the governmental authorities had exceeded their power in granting the use of the bed of the lake to the railroad which could, for all practical purposes, impede navigation except as desired or permitted by the railroad. At the same time it confirmed the right of the railroad to fill and destroy the shallow part of the harbor which was not fit for practical navigation and even went so far as to send the case back to the lower court for a determination whether certain areas had sufficient depth to be navigable.
There is no claim in the present case that the fill for the airport covers a part of the bed of the bay over which the waters are used for other than very casual navigation of the recreational kind.2 It should also be pointed out that in Rlinois Central the purported right had been given to private use and not to another public use as is the case here. Subsequently, Shively v. Bowlby, supra, defined the holding of Illinois Central as follows:
"* * * [I]t was recognized as the settled law of this country that the ownership of and dominion and sovereignty over lands covered by tide waters, or navigable lakes, within the limits of the several States, belong to the respective States within which *202they are found, with the consequent right to use or dispose of any portion thereof, when that can be done without substantial impairment of the interest of the public in such waters, and subject to the paramount right of Congress to control their navigation so far as may be necessary for the regulation of commerce. * * (Emphasis added.) 152 US at 47.
The dispute in Shively was over the ownership in tidelands, and the Supreme Court set forth the following language of the Supreme Court of Oregon in the same case, 22 Or at 427:
«* * * Thg whole question is for the state to determine for itself; it can say to what extent it will preseve its rights of ownership in them, or confer them on others. Our state has done that by the legislation already referred to, and our courts have declared its absolute property in and dominion over the tide lands, and its right to dispose of its title in such manner as it might deem best, unaffected by any 'legal obligation to recognize the rights of either the riparian owners, or those who had occupied such tide lands,’ other than it chose to resign to them, subject only to the paramount right of navigation and the uses of commerce. * * 152 US at 56.
The Supreme Court then said:
"By the law of the State of Oregon, therefore, as enacted by its legislature and declared by its highest court, the title in the lands in controversy is in the defendants in error; and, upon the principles recognized and affirmed by a uniform series of recent decisions of this court, above referred to, the law of Oregon governs the case.” 152 US at 57.
In a discussion of Illinois Central in Sax, "The Public Trust Doctrine in Natural Resource Law: Effective Judicial Intervention,” 68 Mich L Rev 473, 489 (1970), we find the following:
"The Supreme Court upheld the state’s claim and wrote one of the very few opinions in which an express conveyance of trust lands has been held to be beyond the power of a state legislature. It is that result which has made the decision such a favorite of litigants. But the Court did not actually prohibit the *203disposition of trust lands to private parties; its holding was much more limited. What a state may not do, the Court said, is to divest itself of authority to govern the whole of an area in which it has responsibility to exercise its police power; to grant almost the entire waterfront of a major city to a private company is, in effect, to abdicate legislative authority over navigation.”
The article states, after a review of the cases, that "* * * what one finds in the cases is not a niggling preservation of every inch of public trust property against any change,nor a precise maintenance of every historical pattern of use. * * *.
"‡ * * * *
"These traditional cases suggest the extremes of the legal constraints upon the states; no grant may be made to a private party if that grant is of such amplitude that the state will effectively have given up its authority to govern, but a grant is not illegal solely because it diminishes in some degree the quantum of traditional public uses. ” (Emphasis added.)
There is nothing in the public trust doctrine as espoused by Illinois Central or Shively which limits fills of the present kind to those for water-related uses. There is no grant here to a private party which results in such substantial impairment of the public’s interest as would be beyond the power of the legislature to authorize.
Having decided that the public trust doctrine does not prevent all fills for other than water-related uses, we address the next issue which is the extent of the authority granted to the Director to approve permits for fills. This must be determined by an examination of legislative purpose as expressed in the fill and removal law. The legislature expressed its policy in ORS 541.610, as follows:
"(1) The protection, conservation and best use of the water resources of this state are matters of the utmost public concern. Streams, lakes and other bodies of water in this state, including not only water *204and materials for domestic, agricultural and industrial use but also habitats and spawning areas for game and food fish, avenues for transportation and sites for public recreation, are vital to the economy and well-being of this state and its people. Unregulated removal of material from the beds and banks of the waters of this state may create hazards to the health, safety and welfare of the people of this state. Unregulated filling in the waters of this state may result in interfering with or injmying public navigation, fishery and recreational uses of the waters. In order to provide for the best possible use of the water resources of this state, it is desirable to centralize authority in the Director of the Division of State Lands, and implement control of the removal of material from the beds and banks or filling of the waters of this state.
"(2) The Director of the Division of State Lands shall take into consideration all beneficial uses of water including streambank protection when administering fill and removal statutes.
"* * * * *.” (Emphasis added.)
The court finds that it has no unanimity of opinion concerning the authority granted to the Director. The majority believes that it was intended that the Director weigh the extent of the public need for the fill as compared with the public interest in the preservation of the water for navigation, fishing and public recreation and that after doing so he should grant the permit accordingly. The remainder of the court believes that it was the intention of the legislature that water resources be used only to provide a water-related public benefit and that the Director, without regard to the requirements of the public trust doctrine, was not intended to be granted the authority to issue fill permits for other than water-related uses. As can be imagined from the almost evenly divided court, the two competing interpretations of the statutes have been long and arduously debated and any analysis necessarily involves a comparison of the two constructions.
*205No one claims that the provisions of ORS 541.610 are clear, precise or other than ambiguous. Therefore, we examine the balance of the statutes within the fill and removal law as an aid in determining legislative intent. ORS 541.625(2) specifies the considerations imposed upon the Director in granting a permit. They are, in part, as follows:
* * * *
"(2) The Director of the Division of State Lands may issue a permit applied for under ORS 541.620 for filling waters of this state. In determining whether or not a permit shall be issued, the director shall consider the following:
"(a) Whether the proposed fill unreasonably interferes with the paramount policy of this state to preserve the use of its waters for navigation, fishing and public recreation;
"(b) Whether the proposed fill conforms to sound policies of conservation and would not interfere with public health and safety;
"(c) Whether the proposed fill is in conformance with existing public uses of the waters; and
"* * * * (Emphasis added.) *207"(a) The proposed fill does not interfere with the paramount policy of this state to preserve the scenic beauty of its waters and their use for navigation, fishing and public recreation;” (Emphasis added.)
*205This language demonstrates that the legislature intended to allow some interference with the preservation of navigation, fishing and public recreation. It suggests it was not intended to limit permits to water-related uses because it allows interference with such uses as long as the interference is not unreasonable. Whether or not the interference with water-related uses is unreasonable necessarily depends upon the extent of public need for the use which so interferes. The only way this can be determined is by weighing the extent of the public need for the fill against the interference with the named water-related uses. This, we believe, is how the statute was intended to be read.
There is nothing in the statement of policy in ORS 541.610 which leads us to believe that the legislature intended to prohibit the granting of permits for all fills except for water-related uses. If the legislature had so *206intended, it could and surely would have said so in simple terms. It did not. Words such as "Unregulated filling,” "implement control of the * * * filling,” and "shall take into consideration all beneficial uses of water * * * when administering fill * * * statutes,” do not indicate the legislature intended to prevent all uses except those which are water related. It intended that all doubt should be resolved in favor of the protection of the water-related uses of navigation, fishing, and recreation, but it did not intend to prohibit fills for all other uses. No one has suggested how piers for bridges or fills for bridge approaches are going to be permitted if permits are limited to water-related uses and, obviously, they cannot be.3 Bridges for motor traffic are no more water related than are airports for airplanes.
It can be argued that a legislative intent as espoused by this opinion can no more be found in ORS 541.610 than an intent to permit fills for only water-related uses can be found. However, when the balance of the statutory scheme is searched as an aid in determining what was intended by the inexact and ambiguous language of that statute, language is found which indicates a weighing process was intended with any doubt always being cast on the side of preservation. The use of "unreasonably interferes” necessarily requires a weighing process. The statutory format does not make it appear that it was intended that the issuance of permits be limited to situations in which water-related uses do not interfere with water-related uses.
The Attorney General suggested to the legislature a list of enumerated criteria for the granting of permits, which list contained the following:
*207The emphasized portion demonstrates that the Attorney General was advocating a statutory scheme similar to the one which the minority opinion says the legislature enacted. It also demonstrates that the legislature had no intention of adopting such a restriction because it deleted the words "does not interfere” and inserted the words "unreasonably interferes.” It is also interesting to note that the law covers removal of the material from beds of water as well as fills and that in much of the statutory scheme parallel language is used in the statutes without regard to whether it has reference to removals or fills. While it would be foolish to assert that there is no difference between filling waters and removing material from their beds, if it was intended to limit filling to the enumerated water-related uses, it is remarkable that identical language is used in both instances when no one can rationally contend that removal of material must be for a water-related purpose.
Because we hold that the statutory scheme authorizes the issuance of a permit in this case if the Director finds that the public need for the enlargement of the airport outweighs the detriment to the use of the waters in question for navigation, fishing and recreational purposes, and because we hold that the public use doctrine does not prevent a permit in such circumstances, it is necessary to examine the record to see if the Director’s findings justify the issuance of the permit. Such an examination shows that they do not. The Director set out in the right direction by finding that adequate air service at the airport in question was "important to the life and economy of the southern coastal area of Oregon.”4 The same document also contains the following:
*208"In order to help evaluate a fill project in terms of the first two criteria stated above [ORS 541.625(2)(a) and (b)], The Division of State Lands feels it is necessary to first answer the following questions:
******
"3. Does the project fulfill a public need? If it does, what is it?
sfc * H« *
"The Division evaluates the question of unreasonable interference as follows:
"1. If the proposed project has a public benefit, the project is evaluated on its merits, the impact on the public resources of the waterway is determined, and conditions to reduce or eliminate the adverse impacts caused by the project are placed in the permit.
"2. If the project has no public benefit of any kind, then it is unreasonable to use public resources for the project and the project would be denied.
"The airport runway extension has been found to have considerable public benefit. * * *.
«H: ^ ‡ H* H?
"In summary, the evaluation of the airport runway extension project shows that the project benefits the general public * *
However, the final opinion of the Director5 contained the following:
"Issue 2 — Economic Evidence. Evidence was offered by Western Bank et al to show that the Coos Bay-North Bend community needs the airport. The Director in his order dated January 21, 1977, after the first contested hearing, ruled that the John Morse et al contention that there was a ’lack of legitimate need’ for the runway extension was a question that should be argued in the local government forum where the issue was heard. Based on this ruling the hearings officer properly did not allow submission of economic information except as evidence to support the contention that Western Bank et al has standing as a party to this case.
*209"The Director of the Division of State Lands in following the directives of ORS 541.605 et seq. has a responsibility to determine the legitimacy of the project and possible alternative locations for the project. However, the basic concern of the Director is the impact of the project on the natural resources of the waterway involved. The issue of the project’s relative economic impacts on the local community is more properly a subject of local government and its planning functions.”
This clearly demonstrates that the Director was of the opinion that he had no duty to evaluate independently the extent of the public need for the extension of the airport and that he relied upon the determination of the City of North Bend that the public needed it. The extent of the need must be evaluated by the Director before he can balance it against the detriment to navigation, fishing and recreational uses of the water in question. This he failed to do. He also failed to make any ultimate finding of fact that the public need for the airport extension outweighed the detriment to such water-related uses.
In the absence of a finding that the public need predominates, there is no basis for the issuance of the permit and the decision of the Court of Appeals setting aside the issuance of the permit by the Director of State Lands is affirmed.
Former OAR 141-85-205(6) provided:
"Applicants for fill projects must show that the land to be created will be used for a water-related activity * *
As amended by temporary rule, the rule now provides:
"(6) Applicants for fill projects must show:
"(a) How much fill is necessary to accomodate the proposed use. "(b) How the land created will be used.
"(c) Whether or not the project has significant public benefit.
*200"(d) Whether or not filling is necessary to cany out the proposed activity.
"(e) Whether or not the proposed use is consistent with existing land use plans.
"The purpose of this section is to make additional information on fill projects available to the Director and reviewing parties and is not intended to be a limitation on the Director’s authority to issue fill permits.”
The U. S. Army Engineers has granted a permit for the fill in question.
It could be argued that using the water and its bed as an aid to transporting vehicular motor traffic across or over the water is a water-related use. However, this argument is too tenuous because water-related uses under the statute have to do with navigation, fishing, and water recreation.
Director’s finding of fact of January 21,1977, subsequently incorporated in his findings of May 3, 1978.
Document entitled, "FINDINGS OF FACT, OPINION, ULTIMATE FINDINGS OF FACT, CONCLUSIONS OF LAW AND ORDER,” dated May 3, 1978.