N. PATRICK CROOKS, J.
¶ 1. Jim Hilton, acting on behalf of the Pages Homeowners' Association (Association) appeals an unpublished decision of the court of appeals, reversing the decision of the circuit court which had modified the order of the Administrative Law Judge (ALJ)1 requiring that the Association reduce the number of boat slips on its pier. There are three principal issues on appeal: What standard of review must a court apply to an ALJ decision that has [7]*7been expressly adopted by the Department of Natural Resources (DNR) on a matter in that agency's particular area of expertise? Whether the decision of the DNR, adopting that of the ALJ, that a 226-foot, 11-slip pier is the most that "reasonable use" allows, is reasonable, consistent with applicable law, and supported by substantial evidence in the record? Finally, if the DNR decision2 that the Association must reduce the number of slips from its current 22 to 11 is valid, whether the enforcement of that determination would constitute a taking of private property for public use under the state3 and federal4 constitutions, and therefore require the state to pay just compensation?
¶ 2. We affirm the decision of the court of appeals. We hold that because the DNR did not appeal the decision of the ALJ, and adopted by rule the decision as its own, the decision is entitled to great weight deference, because it is a decision within the DNR's area of expertise and satisfies the other necessary criteria. Furthermore, the decision of the DNR was reasonable, consistent with applicable law, and supported by substantial evidence in the record. The decision of the DNR was neither arbitrary nor capricious. Finally, because the issue of whether the reduction in the number of boat slips allowed on the Association pier is an unconstitutional taking is not properly before this court, we decline to address it.
[8]*8HH
¶ 3. The relevant facts are not in dispute. Nelson Page (Page) owned a 77-foot wide riparian lot on Green Lake, as well as nearby nonriparian land. In 1958 and again in 1961, Page subdivided, platted, and recorded the nonriparian land, developed a subdivision, and sold the lots. At the same time, Page also conveyed various undivided 1/38 interests in the riparian lot and a common pier to those buyers who purchased and built on the nonriparian land. The Association, an unincorporated entity, was established in 1966. Association membership consists of those persons who each own the 1/38 interest in the riparian lot.
¶ 4. Since 1966, the Association has placed an unpermitted pier, with various numbers of boat slips, extending from the riparian lot into Green Lake. In 1966, the pier had six boat slips. In 1974-76, the number of slips increased to 11. In 1990, the number of slips had increased to 20. The slips decreased to 16 in 1994-95 then rose to 21 by 2000. Currently, the pier is 249 feet long, 3 feet wide, and contains 22 boat slips. In 1993, when Green Lake County adopted an antipyra-miding ordinance there were 17 slips on the pier.5
¶ 5. The Association first contacted the DNR regarding its pier in 1993, at which point Association [9]*9representatives were told that although the pier's size and density were both excessive under DNR "reasonable use" guidance, the DNR would not commence an enforcement action unless a complaint was received.
¶ 6. In 1997, the DNR received a complaint about possible riparian zone conflicts involving the Association's pier. When the conservation warden inspected the site, an Association member informed him that the Association was interested in increasing the number of slips on the pier above the existing 22.6 The warden explained that the Association would need a permit to do so, and that the DNR would consider reasonable use, cumulative impact, and other public interest factors in deciding whether to issue a permit.
¶ 7. In 1998, the Association asked the DNR if it needed a permit to replace its existing pier with two piers containing 14 slips each. In response to that proposal, and repeatedly over the next four years, DNR staff advised the Association of the DNR's position: that the existing pier and any proposed expansion exceeded Wis. Stat. § 30.13 (1997-98) standards to maintain a pier without a permit; that the Association must apply for a permit if it wished to maintain the current pier or any pier exceeding the § 30.13 (1997-98) standards; if the Association did not reduce the pier to meet the [10]*10standards, or submit a permit application, the DNR would seek an abatement hearing under § 30.03 (1997-98)7
¶ 8. In 1998 and in 2000, the DNR received further complaints about the pier. By June 2001, having still not received a pier permit application, pursuant to its enforcement powers under Wis. Stat. § 30.03 (2001-02),8 the DNR requested an abatement hearing. Going into the abatement hearing, it was the DNR's recommendation that six slips represented the "reasonable use" that the Association pier could legally maintain without a permit.
¶ 9. In May 2002, all Association members but one submitted an application for a pier permit. The abstaining member opposed the application. Because the Association is an unincorporated entity, it does not have the authority to act on behalf of its members unless the members are unanimous. The DNR's policy is that it does not have a complete application for which it can grant a permit unless all owners apply.
¶ 10. The abatement hearing began on August 27, 2002, and testimony ensued for three days. Administrative Law Judge Jeffrey D. Boldt issued his decision in the abatement action on November 22, 2002, and determined that the existing pier violated public rights [11]*11in exceeding the "reasonable use" threshold, negatively impacted the aquatic habitat, and created a safety hazard. After considering both the rights of riparians and the rights of the public, ALJ Boldt determined that the Association should be limited to a 226-foot pier with no more than 11 slips. Eleven slips also happened to be the number he had concluded represented the "historic use" of the pier.
¶ 11. On December 17, 2002, the Association petitioned for judicial review in the circuit court of the DNR decision. The circuit court found that the DNR's determination of the historic use of the pier at 11 slips was arbitrary, without rational basis, and without sufficient basis in the record. The circuit court determined that a better historic use date was 1993, when the antipyramiding ordinance went into effect. At that time there were 17 slips on the pier. Therefore, the circuit court set the number of allowable slips at 17. The DNR appealed.
¶ 12. The court of appeals reversed the circuit court. In an order dated August 18, 2004, the court of appeals determined that the circuit court had applied an improper standard of review and substituted its judgment for the decision adopted by the DNR. The court of appeals, therefore, reinstated that determination. The Association appealed, and this court granted its petition for review.
HH
¶ 13. The parties disagree as to the appropriate standard of review a court should apply to an ALJ determination that has been expressly adopted by the DNR. The Association suggests that the determinations of the ALJ should be reviewed de novo, because the [12]*12DNR failed to employ its expertise in evaluating the ALJ decision. The DNR maintains that the decision is entitled to great weight deference. We agree with the DNR.
¶ 14. In this case, we review the ALJ's determination as a decision of the DNR. See Borsellino v. DNR, 2000 WI App 27, ¶ 5, 232 Wis. 2d 430, 606 N.W.2d 255 (citing Sea View Estates Beach Club, Inc. v. DNR, 223 Wis. 2d 138, 146-47, 588 N.W.2d 667 (Ct. App. 1998)). We do so because "the DNR did not petition for judicial review of the ALJ's decision, and adopted the decision as its own pursuant to § 227.46(3)(a) Stats.,9 and Wis. Adm. Code § NR 2.155(1)." Borsellino, 232 Wis. 2d 430, ¶ 5 (footnote omitted). Wisconsin Admin. Code § NR 2.155(1) provides, in pertinent part, "The administrative law judge shall prepare findings of fact, conclusions of law and decision subsequent to each contested case heard. Unless the department petitions for judicial review as provided in s. 227.46(8), Stats., the decision shall be the final decision of the department.. . ." Wis. Admin. Code § NR 2.155(1) (Sept., 1986). In this case the DNR chose not to appeal the ALJ's decision, "thereby making the ALJ decision its own under its own rule." Sea View, 223 Wis. 2d at 147. Therefore, because the DNR has expressly adopted the ALJ decision, the ALJ decision should be afforded the same deference afforded the agency. Id. at 146-47.
[13]*13¶ 15. When an appeal is taken from a circuit court order reviewing an agency decision, we review the decision of the agency, not the circuit court. Clean Wisconsin v. Pub. Serv. Comm'n, 2005 WI 93, ¶ 36, 282 Wis. 2d 250, 700 N.W.2d 768. The DNR's decision consisted of both findings of fact and conclusions of law. "We apply different standards of review to agency conclusions of law and agency findings of fact." Borsellino, 232 Wis. 2d 430, ¶ 6 (citation omitted). Great weight deference is applied to an agency's legal conclusions when:
"(1) the agency was charged by the legislature with the duty of administering the statute; (2)[ ] the interpretation of the statute is one of long-standing; (3)[ ] the agency employed its expertise or specialized knowledge in forming the interpretation; and (4)[ ] the agency's interpretation will provide uniformity and consistency in the application of the statute."
Clean Wisconsin, 282 Wis. 2d 250, ¶ 39 (citations omitted). Further "the correct test is whether the agency 'has experience in interpreting [the] particular statutory scheme' at issue." Id., ¶ 40.
¶ 16. In reviewing agency findings of fact, we apply the " 'substantial evidence' standard." Borsellino, 232 Wis. 2d 430, ¶ 7 (citation omitted). Wisconsin Stat. § 227.57(6) requires the court to set aside or remand an agency action "if the agency's decision depends on any findings of fact not supported by substantial evidence in the record." Borsellino, 232 Wis. 2d 430, ¶ 7. "Substantial evidence does not mean a preponderance of the evidence." Madison Gas & Elec. Co. v. Pub. Serv. Comm'n, 109 Wis. 2d 127, 133, 325 N.W.2d 339 (1982). [14]*14Instead, the test is whether, after considering all the evidence of record, reasonable minds could arrive at the same conclusion. Id.
¶ 17. Because we conclude this is a decision of the DNR, and that the requirements set forth in Sea View and Roehl Transportation v. Div. of Hearings & Appeals, 213 Wis. 2d 452, 458, 570 N.W.2d 864 (Ct. App. 1997) are met, the DNR's legal conclusions should be granted great weight deference, and the factual findings should be evaluated using the substantial evidence test. Under great weight deference, we will sustain an agency's interpretation, if reasonable, even if an equally reasonable or more reasonable interpretation is offered. Therefore, we will affirm the decision of the DNR if it conforms to applicable law and is supported by substantial evidence from which reasonable minds could arrive at the same conclusion. See Hixon v. Pub. Serv. Comm'n, 32 Wis. 2d 608, 615-16, 146 N.W.2d 577 (1966).
r — 1 hH HH
¶ 18. Our first inquiry is to examine applicable law to determine whether the conclusions of the DNR are consistent with the law governing piers. When considering actions that affect navigable waters in the state, one must start with the public trust doctrine, rooted in Article IX, Section 1 of the Wisconsin Constitution.10 Under the public trust doctrine, "the state of Wisconsin holds the beds of navigable waters in trust for all its citizens.. .." Hixon, 32 Wis. 2d at 618 (citing [15]*15Muench v. Pub. Serv. Comm'n, 261 Wis. 492, 499, 53 N.W.2d 514 (1952)).
¶ 19. The legislature has the primary authority to administer the public trust for the protection of the public's rights, and to effectuate the purposes of the trust. See State v. Bleck, 114 Wis. 2d 454, 465, 338 N.W.2d 492 (1983). Even though the beds of navigable waters are held in trust, "the legislature may authorize limited encroachments upon the beds of such waters where the public interest will be served." Hixon, 32 Wis. 2d at 618 (citing State v. Pub. Serv. Comm'n, 275 Wis. 112, 117, 81 N.W.2d 71 (1957)). Furthermore, under the common law, riparian rights must be reasonably exercised. Borsellino, 232 Wis. 2d 430, ¶ 21 (citing Sterlingworth Condo. Ass'n v. DNR, 205 Wis. 2d 710, 731, 556 N.W.2d 791 (Ct. App. 1996)).
¶ 20. The legislature has delegated to the DNR the duty of enforcing the state's environmental laws. Sea View, 223 Wis. 2d at 149 (citing Barnes v. DNR, 178 Wis. 2d 290, 304, 506 N.W.2d 155 (1993)). Particularly relevant to this case, the legislature "has charged the DNR with regulating piers under §§ 30.12 and 30.13, and the DNR has technical expertise in regulating piers and waterways." Borsellino, 232 Wis. 2d 430, ¶ 6 (citation omitted).
¶ 21. There are three policy factors identified by the legislature that the DNR must balance in enforcing environmental laws related to navigable waters: "the desire to preserve the natural beauty of our navigable [16]*16waters, to obtain the fullest public use of such waters, ... and to provide for the convenience of riparian owners."11 Hixon, 32 Wis. 2d at 620. The legislature has articulated this balancing requirement in Wis. Stat. §§ 30.12 and 30.13, disallowing any deposit or structure on the bed of navigable water that constitutes " 'a material obstruction to navigation'" or is " 'detrimental to the public interest.'" Id. (citation omitted). "The job of applying these two standards in each particular situation was delegated to the [DNR]." Id.
¶ 22. Under existing statutory guidelines, a riparian owner with a lot including 77 feet of shoreline would be entitled by statutory presumption to maintain a pier, without a permit:
no more than 6 feet wide, that extends no further than to a point where the water is 3 feet at its maximum depth,... and which has no more than 2 boat slips for the first 50 feet of riparian owner's shoreline footage and no more than one additional boat slip for each additional 50 feet of the riparian owner's shoreline.
Wis. Stat. § 30.12(lg)(f) (2003-04). However, the public trust analysis requires the DNR to go beyond the statutory presumption to determine what the "reasonable use" is in light of the relevant facts particular to each situation. In this case, the ALJ examined environmental impact, natural scenic beauty, historic use, safety, the statutory presumption, the absence of a permit, and the DNR's delayed enforcement, among [17]*17other factors, in determining "reasonable use." There is ample evidence in the record that the ALJ considered the relevant factors in this case and weighed them appropriately in light of the public trust doctrine. We conclude, therefore, that the decision of the DNR is consistent with applicable law.
IV
¶ 23. Because we have concluded that the DNR's decision to limit the number of permissible slips was consistent with applicable law, we next turn to the DNR's specific findings of fact and conclusions of law. We must determine whether the decision is reasonable and is supported by substantial evidence in the record.
¶ 24. There are four elements of the decision, in particular, that the Association challenges: that the pier directly and cumulatively adversely impacts the aquatic habitat, that the pier presents a safety hazard, that the determination of 11 slips as the "historical use" of the pier was reasonable, and that a 226-foot pier with 11 slips is the most that can reasonably be maintained, without a permit. There is a dispute as to which elements of the decision are findings of fact versus conclusions of law.12 We are satisfied that the first two issues are findings of fact, and the last two are conclusions of law. We will first examine the findings of fact.
[18]*18¶ 25. The "substantial evidence" rule affords significant deference to an agency's factual findings. "The agency's decision may be set aside by a reviewing court only when, upon an examination of the entire record, the evidence, including the inferences therefrom, is such that a reasonable person, acting reasonably, could not have reached the decision from the evidence and its inferences." Sterlingworth, 205 Wis. 2d at 727 (citing Hamilton v. DILHR, 94 Wis. 2d 611, 618, 288 N.W.2d 857 (1980)). Additionally, "the weight and credibility of the evidence are for the agency, not the reviewing court, to determine." Id. (citing Bucyrus-Erie Co. v. DILHR, 90 Wis. 2d 408, 418, 280 N.W.2d 142(1979)).
¶ 26. First, we will examine whether there is sufficient evidence in the record to support the DNR's finding that the Association pier, in its current form, has direct and cumulative adverse impacts to the wildlife and fish habitat in Green Lake. The area in which the Association pier is located is part of the littoral zone13 of Green Lake — the relatively small, shallow portion of the lake. It is in these areas that aquatic plant growth can develop, providing habitat for fish and other aquatic life, stabilizing sediment, improving water quality, and providing sustenance for waterfowl, both migratory and residential.
¶ 27. Green Lake County Conservation Warden Cletus Alsteen (Warden Alsteen) testified that wild celery, upon which migratory birds feed, is limited to growth in the littoral zone. Shawn Eisch (Eisch), a DNR water management specialist, stated that the area, and the access to wild celery, is important for canvasback [19]*19duck and geese migration. Eisch explained that because Green Lake is one of the last lakes in the area to freeze, it provides access to food after snow cover eliminates ground sources. Eisch also testified that it was very apparent that the pier and shading by boats was restricting growth of wild celery in the area. Both the DNR and the Association presented expert testimony that the existing pier configuration and size, as well as the parking of boats in pier slips, shades out beneficial aquatic vegetation in the littoral zone, although they disagreed about the extent of the harm.
¶ 28. Department of Natural Resources fisheries biologist, David Bartz, testified that the pier had a detrimental impact on the fish in the area. He stated that there was no question that fish habitat in the area would improve if the pier and boats in the area were removed. Finally, the ALJ heard testimony from DNR wildlife biologist James Holzwart that, to a reasonable degree of scientific certainty, allowing the pier to remain as it is will continue to have a degrading effect on the aquatic habitat. We are satisfied that there is sufficient evidence in the record to support a reasonable conclusion that aquatic life was and is harmed by the existing pier. As the court in Sterlingworth noted:
Whether it is one, nine or ninety boat slips, each slip allows one more boat which inevitably risks further damage to the environment and impairs the public's interest in the lakes. The potential ecological impacts include direct impacts on the water quality and sediment quality alteration, as well as direct and indirect influences on flora and fauna. For this very reason, the consideration of "cumulative impact" must be taken into account.
[20]*20Sterlingworth, 205 Wis. 2d at 721.14
¶ 29. Next, we turn to the DNR's finding that the existing pier creates a safety hazard due to congestion and impaired visibility. Warden Alsteen testified that the west end of Green Lake, where the Association pier is located, is a heavy use, high boat traffic area. He expressed concerns for safety posed by the fact that the Association pier extends beyond the line of navigation, and is one of the longer privately-owned piers on the western side of Green Lake. Warden Alsteen also expressed concern for safety of swimmers and boaters as a result of the design and congestion of the slips on the Association's pier, which causes limited visibility for boat operations.
¶ 30. In addition, Warden Alsteen testified that the configuration of slips required a boat operator entering the area of the Association pier to maneuver the boat past neighboring piers and boats and turn to enter the slip, as very few slips at the Association pier [21]*21have a straight-line approach. He further stated that even experienced boat operators might have trouble maneuvering in limited space, and such maneuverability becomes even more difficult when compounded by waves and boat wakes. In addition, the ALJ heard testimony that the positioning of the pier and slips may necessitate incursion into neighboring riparian areas while navigating into and away from the pier.
¶ 31. The ALJ, uniquely in a position to weigh the credibility of the testimony of the witnesses, determined that the greater weight of the credible evidence demonstrated that the existing pier constitutes a hazard to navigation because of its length, configuration, and the large number of boats navigating in a relatively narrow access area. There is substantial evidence in the record to support the finding that the Association pier creates a safety hazard.
¶ 32. Next we turn to the conclusions of law, to which we give great weight deference. Under great weight deference, if the conclusions of law are reasonable, are based upon substantial evidence in the record, and are consistent with the applicable law, we will uphold the decision of the agency.
¶ 33. The Association first urges that the DNR's determination that 11 slips constituted the historic use of the pier was not reasonable. In contrast to the DNR's conclusion, the Association maintains that the circuit court's determination of 17 slips as the proper historic use number, dating to the antipyramiding ordinance, is reasonably supported by the evidence.
¶ 34. The Association's position is based upon the assertion that the ALJ ignored the legal methodology for establishing historic use with reference to actual events, as articulated in Sea View, and what it claims is the legal requirement enunciated in Sterlingworth to [22]*22consider similar pier usages on Green Lake. The Association misinterprets the holdings in those cases.
¶ 35. Sea View and Sterlingworth suggest that historical use, however it is determined, is one of the factors that the ALJ may weigh in balancing the private rights and public interests at stake in riparian rights/public trust doctrine cases like this one. See Sea View, 223 Wis. 2d at 155-56; Sterlingworth, 205 Wis. 2d at 733. The cases do not establish any set definition of historical use or any hard and fast methodology for determining it. The court of appeals in Sea View and Sterlingworth did not even use the phrase "historic use" (or "historical use"), let alone define it.
¶ 36. To the extent that the Association is suggesting that historic use must be based on something like passage of an ordinance or DNR contact, that suggestion is without solid underpinnings in the law, and is not required by public policy considerations. In fact, in Borsellino, a case decided shortly after Sea View and Sterlingworth, the court of appeals explained that, under Sea View, "an ALJ may review local ordinances in making a permit determination under § 30.12(2), Stats., but an ALJ is not required to do so." Borsellino, 232 Wis. 2d 430, ¶ 10 (citation omitted).
¶ 37. The DNR found that the evidence showed the following maximum number of members and/or slips in the following years:
Years: Numbers:
1966-68 5-6
1971 8
1972-74 10
1974-76 11
1978 15
1981 17
[23]*231988 05 H
1990 (N N
1991 05 H
1994-95 CO H
2000 H (M
Present IN N
Considering these facts, the ALJ made a determination to use 11 slips as the "historic use" factor, in that "no more than 11 slips were placed at the site for the first 10 years that the Association placed a pier." Although he acknowledged that "the number of slips has increased beyond 11 after 1976," he did not determine that the increase reflected the " 'historic use' but rather the Association's continuing effort to pack as many boats as possible into its small riparian zone to accommodate Association members."
¶ 38. The Association and the circuit court found this conclusion to be unreasonable and arbitrary. We disagree. While the circuit court's conclusions were reasonable, arguably even more reasonable than that of the DNR, the standard of review requires us to decide differently. Certainly, the DNR could have reasonably selected a different number of slips as determinative of the historic use factor, based on the facts of record, but the DNR did not. The Association's argument is apparently that historic use had to be considered to be the high end of the various levels of use through the last 40 years, but that argument is no more reasonable or accurate than what the DNR did in light of the evidence. It would not have been unreasonable, perhaps, if the DNR had selected the original number of slips as the historic use. It must be kept in mind that this is not a case where the same number of slips had remained [24]*24constant over a long period of time. Rather, it is a case where the number of slips started out very small and slowly increased over four decades, sometimes even decreasing in certain years. Thus, the DNR's decision to choose some sort of midpoint as historic use was both supported by substantial evidence in the record and was a reasonable determination.15
¶ 39. We now turn to the DNR's conclusion that an unpermitted reasonable use for the Association is a 226-foot pier with 11 boat slips, which would adequately balance riparian rights with the public interest.
¶ 40. In Sterlingworth, the court of appeals noted that the common law requires "reasonable use" by riparian owners to be determined by " 'the extent and capacity of the [lake], the uses to which it has been put, and the rights that other riparian owners on the same [lake] also have.'" Sterlingworth, 205 Wis 2d at 731, (citing Apfelbacher v. State, 167 Wis. 233, 239, 167 N.W [25]*25244 (1918)). Such an inquiry is a highly fact-specific one, and determinations are made on a case-by-case basis.
¶ 41. In this case, the decision of the DNR that the limit of "reasonable use" by the Association was a 226-foot, 11 slip pier was reasonable, consistent with applicable law, and supported by substantial evidence in the record. The Association was entitled to no more than reasonable use, without a permit, for its pier. Riparian rights have always been qualified by reasonable use and subordinate to public rights. It is evident from the record that the ALJ considered the convenience of riparians, environmental impacts, natural scenic beauty, historic use, safety, the statutory presumption in Wis. Stat. § 30.12(1g)(f)(2003-04), the absence of a permit, and the DNR's delayed enforcement. While not the only reasonable conclusion, the ALJ weighed all of the relevant factors in light of the public trust doctrine and arrived at a conclusion that is reasonable and supported by substantial evidence in the record. Therefore, applying great weight deference, we affirm the ALJ's decision and, thus, the decision of the DNR.
V
¶ 42. Finally, we turn to the Association's argument that the abatement of the present number of boat slips constitutes an unconstitutional taking. Because neither party appealed that portion of the circuit court's decision, the issue is not properly before this court. We decline, therefore, to address it.
[26]*26VI
¶ 43. We hold that because the DNR did not appeal the decision of the AL J, and adopted by rule the decision as its own, the determination is entitled to great weight deference, since it is a decision within the DNR's area of expertise and satisfies the other necessary criteria. Furthermore, the decision of the DNR was reasonable and supported by substantial evidence in the record and was consistent with applicable law. The decision of the DNR was neither arbitrary nor capricious. Finally, we determine that the issue of whether the reduction in the number of boat slips allowed on the Association pier is an unconstitutional taking is not properly before this court. We decline to address it further.
By the Court.— The decision of the court of appeals is affirmed.