On appeal from Department of Environmental Protection.
J. H. Coleman, Baime and D'Annunzio. The opinion of the court was delivered by Baime, J.A.D.
American Cyanamid, Inc. (Cyanamid) appeals from the action of the New Jersey Department of Environmental Protection (DEP) promulgating an amendment to N.J.A.C. 7:13-7.1(d). The sole modification effected by this amendment was to alter the map reflecting the outlines of the flood hazard area surrounding the Raritan River and Peters Brook. The DEP undertook to amend the maps for the Raritan River and Peters Brook to reflect updated data and hydraulic analyses prepared by the United States Geological Survey (U.S.G.S.) for federal flood insurance studies. Modification of the maps was deemed to be necessary because of changes wrought by major stream encroachment applications, flood control projects, dams, revisions requested by private individuals and alterations based upon recent federal studies. 19 N.J.R. 168. As a result of this revision, the geographic area encompassed by flood hazard regulations has been expanded corresponding to a higher theoretical flood elevation. Cyanamid owns a facility in close proximity to the Raritan River in Bridgewater Township. Under the original map, Cyanamid's facility was not subject to land use restrictions because the dike surrounding it was higher than the elevation used to calculate the perimeter of the flood hazard area. Under the revision, however, the elevation of the flood hazard area is higher and overtakes the apical point of Cyanamid's dike, thereby placing portions of the site in a geographic area subject to enhanced land use regulations.
Cyanamid argues that the DEP acted in an arbitrary and capricious manner in its revision of the map reflecting the flood hazard area. This contention is predicated upon several related claims. More specifically, Cyanamid asserts that the DEP
violated the requirements of the Administrative Procedure Act (N.J.S.A. 52:14B-1 et seq.) by failing to adopt standard regulations governing the methodology and computer model utilized in delineating or charting flood hazard areas. It is also argued that the DEP violated several statutory provisions which require it to identify subportions of the flood hazard area for reasonable and proper land use according to the varying degrees of danger to life and property. Cyanamid further contends that the DEP arbitrarily deviated from its own regulations by applying a substantially different flood profile than required. It is also claimed that application of restrictions encompassed by other regulations was overly broad and unjustified. Cyanamid's final argument is that the different treatment accorded to delineated and nondelineated streams is not grounded upon a rational basis.
A brief description of the applicable statutes and regulations is necessary for a complete understanding of the issues presented. The Flood Hazard Area Control Act (Act), N.J.S.A. 58:16A-50, is the operative statutory scheme. The articulated objective of the Act, and hence the primary mission of the DEP, is to protect the "safety, health, and general welfare" of the public by "delineat[ing] and mark[ing] flood hazard areas" and subjecting them to "land use regulations." N.J.S.A. 58:16A-50(b). The Act confers broad authority to the DEP to accomplish its assigned goal. Under the Act, the DEP is empowered to map flood hazard areas, adopt land regulations, control stream encroachments, coordinate the development, dissemination, and use of relevant information and integrate the control activities of municipal, county, state and federal governments. Ibid.
Perhaps, the principal function of the DEP is to "study the nature and extent of the areas affected by flooding in the State." N.J.S.A. 58:16A-52a. The Act directs the DEP
"[a]fter public hearings [and] upon notice, and pursuant to the Administrative Procedure Act [citation deleted] [to] adopt rules and regulations which delineate as flood hazard areas such areas as, in [its] judgment, the improper development and use of which would constitute a threat to the safety, health, and general welfare from flooding." Ibid. The Act further provides that "[s]uch delineations shall identify the various subportions of the flood hazard area for reasonable and proper use and according to relative risk, including the delineation of floodways necessary to preserve the flood carrying capacity of natural streams." Ibid. In this regard, the words "relative risk" are defined in terms of the "varying degrees of hazard to life and property in a flood hazard area which are occasioned by differences in depth and velocity of flood waters covering and flowing over it." N.J.S.A. 58:16A-51(d). The Legislature obviously envisioned changes in delineations caused by external circumstances as well as by updated data. In this respect, the Act provides that the DEP may, after public hearing and notice and subject to the provisions of the Administrative Procedure Act, "revoke, amend, alter, or modify such regulations if in its judgment the public interest so warrants." N.J.S.A. 58:16A-52a. While the Act requires the DEP to "establish a procedure for reducing any delineated flood hazard area when a change has been made which increases the flood carrying capacity of the concerned stream," N.J.S.A. 58:16A-52c, the statutory scheme is entirely silent respecting the converse situation. In other words, the statute does not mandate that the DEP adopt a procedure for redelineation expanding the flood hazard area where changes have decreased the flood carrying capacity of the stream.
As noted previously, one of the more significant functions of the DEP is to coordinate the dissemination and use of information on floods and flood damages and integrate the flood control activities of the federal, state, county and municipal governments. N.J.S.A. 58:16A-50b. The Legislature contemplated that, at least to some extent, the DEP would follow the
lead of the federal government in delineating flood hazard areas. N.J.S.A. 58:16A-52b states that the DEP "shall wherever practicable, make floodway delineations identical to the floodway delineations approved by the Federal Government for the National Flood Insurance Program."
Pursuant to its rule-making authority, the DEP has adopted a series of regulations designed to implement the provisions of the Act. N.J.A.C. 7:13-1.1 et seq. Where the DEP has specified the location of a flood hazard area for a particular stream, the stream is said to have been "delineated." N.J.A.C. 7:13-1.1(b)(1). When the DEP has not designated the flood hazard area for a stream, it is said to be "nondelineated." N.J.A.C. 7:13-1.1(b)(2). Since the DEP is statutorily required to make a risk assessment in choosing which streams to delineate, see N.J.S.A. 58:16A-52a, we are advised by the agency that it has delineated first the largest streams with the greatest velocity because they present an enhanced flooding danger.
The flood hazard area is determined by the "flood hazard area design flood," which is defined as the 100-year storm in nondelineated areas and the 100-year storm plus 25% (the "25% add-on") in delineated areas. N.J.A.C. 7:13-1.2. Stripped to its essentials, the flood hazard area is deemed to be that geographic expanse adjacent to a stream which will be inundated by a storm of a particular size. For nondelineated streams, the DEP uses the 100-year storm, meaning a storm of a size that is expected to occur once a century or have a one percent chance of occurring in any one year. See N.J.A.C. 7:13-1.2, which defines a "one hundred year flood plain." With respect to a delineated stream, the DEP defines the flood hazard area as the area covered by the 100-year storm plus the 25% add-on, which is an additional 25% of the volume of water created by the 100-year storm. The DEP then plots the water surface elevation for the design flood at cross-sections on a map, see 20 N.J.R. 392, and connects these elevations with lines that delineate the flood hazard area.
It is important to note that the 100-year storm is not based on any actual storm. Instead, a theoretical storm is constructed by using mathematical models. A hydraulic computer model is applied to generate the width and location of the floodway at each cross-section at which the stream is measured. The water surface elevation for the design flood is plotted onto a corresponding topographical map showing relative ground elevations. 20 N.J.R. 392. Areas in which the plotting reveals the flood elevation of the theoretical design flood to be higher than the ground elevation are then included within the flood hazard area. In determining the volume of water and other characteristics of the theoretical design flood, the DEP uses one of several hydraulic computer models. Although the format of each program is different, the models apparently generate substantially the same answers. While we will describe the models generally employed later in our opinion, we merely observe at this posture that the different computer models utilized are not presently the subject of any regulation. The particular model chosen by the DEP depends upon the model used by the federal government, which is essentially a question determined by contract.
The variation in programs in State delineations thus reflects the use of a number of different computer methodologies in the federal flood insurance program. The DEP uses these models whenever possible in order to comply with the statutory mandate requiring the use of floodway delineations "approved by the Federal Government for the National Flood Insurance Program." N.J.S.A. 58:16A-52b. As we have pointed out, no single computer model is used for the federal flood insurance program because the Federal Emergency Management Agency (FEMA) contracts with a number of different agencies and private firms to perform the technical calculations by which flood-prone areas are identified. 42 U.S.C., § 4101 et seq. Under the federal statute, the Secretary of Housing and Urban Development is authorized to enter into contracts for the purpose of retaining public agencies or private companies to perform
delineations of flood hazard areas. 42 U.S.C. § 4101(a). The object is to "establish flood-risk zones" with a view toward identify[ing] and publish[ing] information" as to "flood plain areas. . . ." 42 U.S.C. § 4101(a)(1). Thus, our statutory and regulatory framework interfaces with its federal counterpart.
Returning to New Jersey's regulations, N.J.A.C. 7:13-1.2 divides flood hazard areas into two parts, called the "floodway," which is basically the stream channel and those areas immediately adjacent to the channel needed to carry away flood waters, and the flood fringe area. While we are not concerned here with nondelineated streams, we note that they have been divided in a somewhat similar manner. The floodway equivalent is "the encroachment line," ibid., and the flood fringe area is the 100-year flood plain.
Key to the present dispute is the fact that strict land use restrictions apply in the flood hazard area. In the floodway of a delineated stream and within the encroachment line of a nondelineated stream, virtually all construction of structures and addition of fill is prohibited. N.J.A.C. 7:13-3.1(a). In the flood fringe area of a delineated stream and the 100-year flood plain of a nondelineated stream, most fill activity is also prohibited. N.J.A.C. 7:13-4.7(d) limits fill and structures to 20% of the volume of net fill in such areas. In addition, construction is sharply limited. N.J.A.C. 7:13-4.7(c). In contrast, property outside the flood fringe area is not subject to any net site limitation or land use restriction under the Act or or its implementing regulations.
It is against this statutory and regulatory backdrop that we examine the facts of this case which are essentially undisputed and a matter of public record. As we mentioned at the outset of our opinion, Cyanamid owns a 600 acre facility in the area of the Raritan River. The area was originally delineated in 1972 by the Division of Water Policy under the auspices of the
predecessor statute. L. 1962, c. 19. Apparently relying on this 1972 delineation, Cyanamid constructed a dike which bordered its facility to be higher than the flood hazard area design flood elevation. After Cyanamid built the dike, the DEP on at least three occasions over the next 16 years readopted the 1972 delineation. Each of these regulatory actions left unchanged the 1972 ...