DORIS, J.

This is a civil action for a declaratory judgment brought under the provisions of the Uniform Declaratory Judgments Act, G.L. 1956 (1969 Reenactment) chapter 30 of title 9. The case was tried to a justice of the Superior Court sitting without a jury who entered judgment for the defendant. From this judgment, the plaintiffs now appeal.

The plaintiffs, a Rhode Island corporation, together with certain individuals, are owners of approximately one hundred acres of land in the Towns of Cumberland and Lincoln. In 1969, as part of a reclamation project, plaintiffs attempted to relocate some 3800 feet of the Blackstone River where it ran through their property. The director of Natural Resources required plaintiffs to submit detailed plans of the projected relocation, and after public hearings on the question, plaintiffs were ordered to cease all filling operations and to restore the river to its natural course.

On July 27, 1970, plaintiffs filed a complaint in Superior Court alleging that the department lacked jurisdiction over the relocation of the river. On July 2, 1971, after a hearing, judgment was entered for plaintiffs on the grounds the department lacked jurisdiction to order the reclamation stopped.

On July 16, 1971, the Legislature passed the "Fresh Water Wetlands Act" (hereinafter termed the Act), G.L. 1956 § 2-1-18 to § 2-1-24. The Act provides for regulation of all fresh water wetlands, a classification into which plaintiffs' property admittedly falls. It opens with a declaration of state policy in regards to wetlands; it then proceeds to define the geographical jurisdiction of the Act and to declare that approval of both the director of the Department of Natural Resources and the municipality in which the land is located is required before a wetland may be altered; the procedure for obtaining such approval is outlined and the Act closes with a delineation of the authority of the director to respond to violations of the provisions of the Act.

On May 18, 1973, plaintiffs filed a complaint for a declaratory judgment alleging that unless defendant, the director of Department of Natural Resources, is restrained from enforcing the Act they will suffer irreparable harm. The complaint further alleges that the Act is unconstitutional on its face in that it is an unlawful delegation of legislative authority, that it denies its subjects the equal protection of the law, and that it deprives the landowner of the beneficial use of his property without just compensation.

The defendant filed an answer denying plaintiffs' allegations of unconstitutionality, and both parties proceeded to file motions for summary judgment. After memoranda of law were submitted by the parties and amicus curiae, a hearing was scheduled before a justice of the Superior Court sitting without a jury. At the close of oral argument, the Superior Court held that the Act was not unconstitutional on its face, denied plaintiffs' motion for summary judgment, and granted defendant's motion.

Judgment for defendant was entered on October 18, 1973, and on October 23, 1973, plaintiffs filed their notice of appeal to this court. During the pendency of the appeal, the Act was amended by P.L. 1974, ch. 197, which in important part added a subsection to § 2-1-21. On appeal, plaintiffs develop the same arguments of unconstitutionality they offered below, directed this time towards the Act as amended.

We first address ourselves to the question of whether we should consider the Act as it existed at the time the case was heard below or in its amended form. There is a division of authority on the issue of whether an appellate court should apply the law existing at the time of its decision or the law existing at the time of the judgment below. Annot., 111 A.L.R. 1317 (1937). This court has noted that the resolution of this issue will depend on the peculiar nature of the case presenting the issue. Twomey v. Carlton House of Providence, Inc., 113 R.I. 264, 320 A.2d 98 (1974). Thus in recent years we have reached differing results when confronted with different kinds of cases. Compare Goodman v. Zoning Bd. of Review, 105 R.I. 680, 254 A.2d 743 (1969) with H.J. Bernard Realty Co. v. Director of Employment Sec., 104 R.I. 651, 248 A.2d 245 (1968) and King v. Brown, 102 R.I. 42, 227 A.2d 589 (1967).

Other jurisdictions have generally held that the right to an injunction will be determined on appeal according to the law prevailing at the time the decision is rendered on the theory that the rights at issue are future rights only. Annot., 111 A.L.R. supra at 1328; 5B C.J.S., Appeal and Error § 1841 (1958). We note that the instant action is for a declaratory judgment and could not possibly involve the abrogation of substantive rights already vested, the rights in question are all in futuro.

We also note that in zoning cases we have applied the law prevailing at the time of our decision on the theory that the public's interest in the zoning scheme should outweigh the individual's right to obtain a permit, at least in the situation where the landowner has not relied to his detriment on the original ordinance. Goodman v. Zoning Bd. of Review, supra; A. Ferland Sons v. Zoning Bd. of Review, 105 R.I. 275, 251 A.2d 536 (1969). A similar balance of interest obtains in the instant case except that here the landowners are actually requesting that the Act be considered as amended.

This factor of the public interest in the result of the decision may be applied to the question of what law should govern the decision in a somewhat different way. The United States Supreme Court has suggested that in a suit involving the limited concerns of two private parties, a court should attempt to avoid a construction having a retrospective impact on the rights of the parties, but that where great public rights are involved a construction of the present impact of the law should be attempted. United States v. Schooner Peggy, 5 U.S. (1 Cranch) 103, 2 L.Ed. 49 (1801), cited by Annot., 111 A.L.R. supra at 1326. In the instant case, plaintiffs are attempting to litigate the validity of a legislative enactment affecting the rights of all owners of wetlands and not merely the impact of the Act upon their own piece of property.

Finally, the determination that an appellate court should apply the law prevailing at the time of the decision below is based on the postulate that the basic function of an appellate court is to review the judgments made below for errors of law. While we subscribe to this view as a general principle, it is clear that its application is of substantially less force in a declaratory judgment action which presents pure issues of law on which the appellate court must in any case render an independent judgment.

The combined weight of these various factors convinces us that we should pass on the constitutionality of the Act in its amended form. We proceed now to an examination of plaintiffs' various allegations of unconstitutionality.

I

The plaintiffs' first contention is that the Act attempts to delegate legislative power in violation of R.I. Const. art. IV, §§ 1 and 2. The delegation is contained in § 2-1-21 as amended by P.L. 1974, ch. 197, and gives to the director of the Department of Natural Resources and the municipality in which the land is located, the authority to approve or disapprove a landowner's application to alter the character of any fresh water wetland. Section 2-1-21 reads in relevant part as follows:

"Such approval will be denied if in the opinion of the director granting of such approval would not be in the best public interest. Such approval shall not be granted if the city council or town council of the town within whose borders the project lies shall have disapproved within forty-five (45) days period provided for objections set forth in § 2-1-22. Appeal from such denial may be made to the superior court."

The plaintiffs argue that this language does not cloak the legislative delegation with sufficient standards confining the exercise of the power delegated to the public welfare sought to be served. They also argue that it fails to provide adequate guidelines for meaningful judicial review.

The nondelegation doctrine in Rhode Island stems from R.I. Const. art. IV, §§ 1 and 2, which provides that the Rhode Island Constitution shall be the supreme law of the state and that under the Constitution the legislative power shall be vested in the two houses of the Legislature. These sections, however, are not construed to prohibit entirely the delegation of legislative power. City of Warwick v. Warwick Regular Firemen's Ass'n, 106 R.I. 109, 256 A.2d 206 (1969). To the contrary they have been held to require only that a delegation of legislative power be cloaked with adequate standards. State ex rel. Colvin v. Lombardi, 104 R.I. 28, 241 A.2d 625 (1968); Opinion to the Governor, 91 R.I. 346, 162 A.2d 802 (1960).

With this relaxation of the nondelegation doctrine has come the realization that the adequacy of legislative standards cannot be meaningfully measured against some abstract limitation contained in R.I. Const. art. IV, §§ 1 and 2. Thus recent decisions have taken into account such factors as the need of the Legislature to utilize an administrative agent to accomplish the purposes of the legislation and secondly public benefit accruing from the enactment of legislative standards to accompany the delegation.

In Pascale v. Capaldi, 95 R.I. 38, 41, 182 A.2d 435, 436 (1962), we concluded that a delegation to the director of public works was valid where it was "* * * the most practical manner in which the legislative power to condemn may be exercised." Likewise in City of Warwick v. Warwick Regular Firemen's Ass'n, supra at 113, 256 A.2d at 209 we stated that:

"Where the purposes of the antecedent legislative enactment may be best accomplished through the employment of an agent acting in its stead, the legislature may delegate to that agent a sufficient portion of its power to enable it to make the statute operative."

In addition to this practical limitation on the standards required for a valid delegation is the conclusion that the adequacy of legislative standards may best be measured against their intended purposes. In City of Warwick v. Warwick Regular Firemen's Ass'n, supra, for example, we concluded that the standards prescribed in the legislation were sufficient to accomplish their bifurcated purpose of limiting the discretion of the administrative delegates and providing a basis for judicial review of the actions taken pursuant to the authority delegated.

With these general principles in mind, we proceed to consider the validity of a delegation of authority to the director of the Department of Natural Resources to disapprove applications to alter fresh water wetlands. Section 2-1-21 requires anyone who would alter the character of a wetland to obtain the approval of the director and fixes the governing standard as the "best public interest." The plaintiffs argue that this is not a meaningful standard. In response to this contention, we first note that the director is given jurisdiction over only a very limited area, wetlands. The term "wetlands" is precisely defined in § 2-1-20. In a previous case where this court found a valid delegation of authority to the Blackstone Valley Sewer District Commission, City of Central Falls v. Halloran, 94 R.I. 189, 179 A.2d 570 (1962), we placed great weight on the fact that the administrative agency was given discretion to act only in a well-defined geographical area. Here, also, the scope of administrative authority is clearly confined.

Secondly, the Legislature in §§ 2-1-18 and 2-1-19 has set forth basic legislative policy in the area of wetlands. Section 2-1-18 recognizes specifically the valuable function played by wetlands in acting as buffer zones and absorption areas for flood waters and providing both wildlife habitats and recreational areas. The section goes on to say that protection of such wetlands for those and other stated purposes is in the "best public interest." Section 2-1-19 reiterates that it is state policy to preserve wetlands and declares that in order to accomplish this purpose, wetlands shall be regulated under the police power.

It is our opinion that the repetition of "best public interest" in § 2-1-21, the delegation section, may reasonably be construed to incorporate the contents of §§ 2-1-18 and 2-1-19. Thus § 2-1-21 delegates to the director the authority to disapprove an application whenever the proposed project would thwart the policies expressed in § 2-1-19 to preserve wetlands in order that they may continue to carry out the functions expressly enumerated in § 2-1-18. This court has consistently held that the stated purposes of a legislative enactment are relevant to the issue of whether the delegation was adequately cloaked with standards. Pascale v. Capaldi; City of Central Falls v. Halloran; City of Warwick v. Warwick Regular Firemen's Ass'n, all supra.

We conclude that the Legislature has thus enacted into law the general policy of preserving fresh water wetlands in order that the functions of these wetlands as enumerated in § 2-1-18 may continue to be fulfilled. Pursuant to this authoritative statement in the best public interest, an administrative official has been delegated the power to make case-by-case determinations of whether a proposed project would significantly inhibit the present valuable functions of wetlands. In our opinion the statements of purpose and policy contained in the Act adequately limit the discretion of the director, and the Act therefore does not violate R.I. Const. art. IV, §§ 1 and 2 in granting authority to the director of the Department of Natural Resources accordingly to disapprove applications to alter fresh water wetlands.

We move now to a consideration of the delegation of authority to municipal units to disapprove an application to alter a wetland. Section 2-1-21(a) states in pertinent part that:

"* * * approval shall not be granted if the city council or town council of the town within whose borders the project lies shall have disapproved within the forty-five (45) days period provided for objections set forth in § 2-1-22."

The plaintiffs argue that this constitutes a delegation without even the best public interest standard and is therefore invalid.

Assuming, without deciding, that the nondelegation doctrine applies equally to the conferring of legislative power upon a unit of local government as to like delegation to a legislatively-created agency, we would find no violation of that doctrine here. The clear thrust of § 2-1-21 is to confer upon the director the authority to decide whether a proposed wetland alteration is in the "best public interest," which determination is to be made by him, as we have already indicated, by reference to the express legislative statements of purpose and policy contained in §§ 2-1-18 and 2-1-19. To read the final sentence of § 2-1-21 to confer upon local government the power to disapprove a proposed wetland change without regard to those same purpose and policy standards would be, in our opinion, a highly dubious if not absurd construction of that sentence and one we are therefore unable to accept. Thus, while there are no express limitations placed on a town's or city's authority under § 2-1-21, the same standards that control the director's determinations obtain by implication to actions taken thereunder by local governmental units.

This would mark the conclusion of our inquiry into the validity of powers delegated by this Act were it not for the fact that plaintiffs' brief on appeal attacks not only the dearth of standards in § 2-1-21 but also the nature of the authority delegated to the municipalities. They characterize this authority as an "unfettered, arbitrary and capricious veto power." Furthermore, the parties have stipulated that the decision of the Superior Court in the case of Colapietro et al. v. Murphy, C.A. No. 74-1734 may be added to the record before us. The text of this decision develops an argument which attacks the delegation to a municipality of power to disapprove an application to alter a wetland on the grounds of denial of due process under U.S. Const. art. XIV, § 1. In the interests of judicial economy and believing the parties intended to incorporate these arguments, we will briefly consider the issues.

At the outset the parties would undoubtedly accept the principles that the Legislature may neither authorize arbitrary or otherwise unconstitutional action by a city or town council nor delegate the authority to do what it could not do itself, and that there exist potential limitations on the authority a delegatee may exercise other than those arising from R.I. Const. art. IV.

The authority delegated by § 2-1-21 is the authority to regulate the use of fresh water wetlands within municipal boundaries. This court has held that the exercise of such power is the exercise in part of the state police power. Atlantic Tubing Rubber Co. v. City Council, 105 R.I. 584, 254 A.2d 92 (1969); State v. Krzak, 97 R.I. 156, 196 A.2d 417 (1964). In the Atlantic Tubing case, we noted that a municipality's authority to regulate the use of private property within its jurisdiction, being an exercise of the police power, is not inherent and is possessed by the municipality only by a grant from the Legislature. We went on to say that the exercise of such authority must be in accordance with the limitations on the police power. It is settled law that the exercise of the state's police power by municipality must be consistent with the law and policy of the state and that such exercise must not be arbitrary, capricious, or confiscatory. McQuillin, supra, § 24.46.

As these inherent limitations on the exercise of the police power are necessarily included in § 2-1-21, the city and town councils have been granted the authority to disapprove an application to alter a wetland only where such disapproval would not violate the constitutional rights of the landowner and where it is in accordance with the state policy on wetlands as established in §§ 2-1-18 and 2-1-19 of this Act. That being so, we conclude that the authority granted by § 2-1-21 is not unconstitutional on its face as a denial of substantive due process.

Nor does § 2-1-21, as written, deny a landowner procedural due process. The Act grants the municipality the power to share in the regulation of wetlands within its boundaries, but it does not specify the procedures by which this municipal regulation is to be accomplished.

[5,6] Having concluded, however, that a city or town council may disapprove an application under § 2-1-21 only if the "best public interest" would otherwise be violated, it follows that its proceedings are judicial in character and that, as a condition precedent to those actions, an applicant is entitled even in the absence of statutory language providing therefore to due notice of a hearing, and an opportunity to be heard and offer evidence. See Davis v. Cousineau, 97 R.I. 85, 196 A.2d 153 (1963); Cugini v. Chiaradio, 96 R.I. 120, 189 A.2d 798 (1963); Aniello v. Marcello, 91 R.I. 198, 162 A.2d 270 (1960); Norton v. Adams, 24 R.I. 97, 52 A. 688 (1902). Whether the municipal council has succeeded in satisfying those preconditions in a given case is a question that may be raised on appeal to Superior Court. By providing for judicial review, the Legislature has given the landowner the opportunity to attack the decision below on the grounds that it denies him procedural or substantive due process or that it frustrates state policy by not taking cognizance of the considerations set out in §§ 2-1-18 and 2-1-19. Should the municipal council fail to specify its findings of facts or its reasons for disapproval, its decision should be dealt with by the Superior Court which is vested with jurisdiction to hear appeals in such matters in the same manner as would be an appeal from an agency decision under the Administrative Procedures Act. We cannot say at this time that § 2-1-21 denies a landowner due process of law.

II

The plaintiffs' second contention is that the Act denies them equal protection of the law as guaranteed by U.S. Const. amend. XIV, § 1. They allege that owners of fresh water wetlands are accorded different and less favorable treatment under the General Laws of Rhode Island than are owners of salt water wetlands.

Unless a suspect classification is created, a legislative decision to distinguish between two sets of persons will be upheld if it has any rational basis. Dandridge v. Williams, 397 U.S. 471, 90 S.Ct. 1153, 25 L.Ed.2d 491 (1970). In order to establish a denial of equal protection in the instant case, plaintiffs must show that owners of fresh and salt water wetlands are similarly situated and that the differences in procedure adopted by the Coastal Wetlands Act, §§ 2-1-13 to 2-1-17 and by the instant Act lack all rational basis.

The Coastal Wetlands Act envisions affirmative action on the part of the Department of Natural Resources to the end of establishing a statewide plan for the protection of wetlands. The instant Act, on the other hand, sets out a permit procedure whereby the landowner is required to initiate the proceedings. This difference in overall approach is susceptible to a variety of reasonable explanations: the greater development pressure on coastal wetlands suggests the need for immediate state action while the situation regarding fresh water wetlands might not be so pressing; the high incidence of state-ownership in coastal wetlands might facilitate centralized action while the almost exclusively private ownership of fresh water wetlands would tend to hinder such an approach; the probable interdependence and interactions of coastal wetlands could necessitate unitary state action while the more random pattern of fresh water wetlands might thwart such an attempt.

Having in mind the need for significantly different approaches to the regulation of fresh and salt water wetlands, the Legislature could reasonably conclude that the two methods of regulation posed dangers of differing magnitude to the rights of private individuals. Thus they may have decided that a statewide program of affirmative action, being less sensitive to individual circumstances, required the inclusion of prior hearings and a provision for compensation, while a procedure that envisioned the processing of a series of individual applications required only the availability of judicial review to ensure the protection of all constitutional rights, including that of just compensation. In these circumstances, we cannot say that the classifications created by the Legislature lack all rational basis. The plaintiffs' argument is without merit.

III

The plaintiffs' final contention is that § 2-1-21(b) deprives them of property without just compensation in violation of U.S. Const. amend. V, § 1 and R.I. Const. art. I, §§ 2 and 16. They do not include the provisions of § 2-1-21(a) in their challenge. As we believe the provisions of § 2-1-21(b) cannot be meaningfully construed without an understanding of the preceding subsection, we first examine the function of § 2-1-21(a) in the context of the just compensation issue.

The final sentence of § 2-1-21(a) provides that appeal from the denial of approval to alter the character of a wetland may be taken to the Superior Court. The formal denial of such approval will in all cases come from the Department of Natural Resources, a body whose actions are governed by the provisions of the Administrative Procedures Act, G.L. 1956 (1969 Reenactment) §§ 42-35-1 to 42-35-18. Section 42-35-15 provides for judicial review of contested cases. It specifically gives an aggrieved party the right to raise all legal issues concerning the validity of the agency decision, including all relevant constitutional issues. Section 42-35-15(g)(1).

As the Act does not confer the power of eminent domain on the director, his decision to withhold approval of a proposed alteration may be attacked on appeal as a denial of any beneficial use of the landowner's property and a violation of the constitutional right not to have that property taken without just compensation. U.S. Const. amend. V; R.I. Const. art. I, § 16. If this contention were upheld, presumably the action of the director would be null and void, and the landowner, as a matter of constitutional right, would be permitted to proceed with his project. Thus the Act, by incorporating the provisions of the Administrative Procedures Act, gives any landowner the opportunity to vindicate his constitutional rights in a judicial forum. By reserving to the courts the question of whether the Act as applied may be unconstitutional, § 2-1-21(a) is clearly constitutional on its face.

The plaintiffs, however, base their arguments on § 2-1-21(b). This subsection reads as follows:

"Whenever a landowner shall be denied approval to alter a wetland by the director, or by the city or town within whose borders the wetland lies under subsection (a), the landowner may elect to have the state, or such city or town, acquire the land involved by petitioning to the superior court. If such court shall determine that the proposed alteration would not essentially change the natural character of the land, would not be unsuited to the land in the natural state, and would not injure the rights of others, the court shall, upon determining the fair market value of the wetland, based upon its value as a wetland, direct the state, if approval were denied by the director, or the city or town, if approval were denied by such city or town, or both, if they concurred in such disapproval, to pay to the landowner the fair market value of the wetland; provided, however, that if the state, or the city or town, or both, where both are ordered to pay, shall decline such acquisition, the landowner may proceed to alter the wetland as initially requested. Any amount paid by the state hereunder shall be paid from any funds in the treasury not otherwise appropriated. If the director of natural resources alone denied approval under subsection (a) then the city or town shall make payment. If both the state and the city or town denied approval then payment shall be shared equally by the state and the city or town."

While the intended impact of this subsection is admittedly ambiguous, this court must construe a duly enacted statute to be constitutional if such construction is reasonably possible. Giving this admonition due weight, we note that the subsection speaks in terms of "electing" to petition to the Superior Court. This language suggests that the Legislature viewed § 2-1-21(b) as an alternative to the review procedure provided in § 2-1-21(a), a non-essential addition to the statute supplementing, but in no way limiting, the landowner's right, already secured by the previous subsection, to raise all relevant constitutional claims.

An examination of the relative kinds of review offered by the two subsections reinforces this construction; they are in no sense duplicitous. Section 42-35-15(g) states specifically that the reviewing court shall not substitute its judgment for that of the agency on questions of fact. To overturn a decision on factual grounds, a landowner must establish that it is "clearly erroneous in view of the reliable, probative, and substantial evidence on the whole record." Section 42-35-15(g)(5).

Earlier in this opinion we noted that the director would disapprove a landowner's application when he concluded that the proposed alteration would thwart the legislative mandate to preserve and protect wetlands in order that they continue to fulfill the functions specified in § 2-1-18. We also noted that this determination inevitably invokes difficult factual questions of a scientific nature. With the scope of review provided by § 42-35-15, the landowner faces a difficult task if he should wish to contest the findings made below as to the ecological impact of his proposed project. If, however, a landowner elects to petition under subsection 2-1-21(b), the Superior Court must make an independent determination of whether "* * * the proposed alteration would not essentially change the natural character of the land, would not be unsuited to the land in the natural state, and would not injure the rights of others * * *." (Emphasis added.) In effect these determinations constitute a de novo review of the essential questions of fact and law in the case. Should the court decide that the landowner is correct in his contention that the proposed use will not essentially alter the natural character of the land, and by implication that the director was incorrect in denying his approval, then the landowner must either be compensated or he must be allowed to proceed with his project. This compensation provision does not replace the judicial determination on appeal under § 2-1-21(a) of what, in the event that the director was correct in his disapproval, would constitute just compensation for taking. Rather, it functions as a gratuitous offer by the state to purchase a landowner's property in some cases where the director is found to have overestimated the impact of a proposed alteration.

We anticipate that § 2-1-21(a) will be the usual avenue of appeal and that the provisions of § 2-1-21(b) will be invoked only where an appeal under § 2-1-21(a) proves unavailing or where the landowner allows the appeals period to run, thereby foregoing his opportunity to raise issues of a constitutional dimension. If then, § 2-1-21(b) is so construed only as a limited supplementary remedy giving those landowners who have no interest in substantially altering the character of their wetlands an opportunity to gain de novo review of certain essential issues of fact and law, the Act does not on its face deprive any person of property without just compensation.

For the reasons stated, the plaintiffs' appeal is denied and dismissed, and the judgment appealed from is affirmed.