Court Opinion

ID: 9538797
Source: CourtListenerOpinion
Date Created: 2023-08-07 07:41:49.994692+00
Date Added: 2024-06-11T14:58:10.197242
License: Public Domain

KENNARD, J., Dissenting.
When a public entity enacts a zoning ordinance prohibiting owners of private property from using their land in a specified manner, it generally permits those property owners already using their land in the prohibited manner to continue doing so, as a “nonconforming use.” This case concerns the degree to which public entities may regulate the scope of a nonconforming use; the nonconforming use here is mining.
Originally, plaintiff’s mining operations consisted almost entirely of scraping up gravel that had washed down a river, but plaintiff also operated a small rock quarry on land adjacent to the river. After a county ordinance was passed prohibiting mining in the area involved, plaintiff was permitted to continue mining as a nonconforming use. Now, because an upstream dam has rendered plaintiff’s riverbed operations virtually worthless, plaintiff seeks to greatly expand the intensity of its quarrying operations, and to remove rock at an annual rate of up to 250 times greater than past removal by plaintiff. The county planning commission, the county board of supervisors, the superior court, and the Court of Appeal all concluded that whatever right plaintiff enjoyed to scoop gravel from the riverbed could not be converted into a right to quarry rock out of the adjacent hillsides, and that plaintiff’s planned expansion exceeded the scope of its right to mine the property as a nonconforming use. A majority of this court 1 comes to a contrary conclusion, holding that plaintiff’s two mining operations—those in the riverbed and those on the adjacent land—must be viewed as a single *582nonconforming use. The majority directs the Court of Appeal to remand the case to the trial court for reconsideration in light of this conclusion.
I disagree with the majority. Substantial evidence supports the determinations by the board of supervisors and the trial court that plaintiff’s mining of the riverbed and its mining of the adjacent land were separate uses. Viewed in this light, plaintiff’s proposed plan represents a substantial intensification of its previous mining operations, and is therefore beyond the scope of its nonconforming use.
I
Since 1946, mining has been conducted on land that plaintiff purchased in 1954. The land is located on the Bear River, which divides Nevada and Placer Counties; the site is a wooded, scenic area near the town of Colfax, in the Sierra foothills. The mining involves roughly 60 acres, most of which is in Nevada County.2
In 1954, the Nevada County Board of Supervisors adopted a zoning ordinance prohibiting mining in an area that included plaintiff’s property. Nevertheless, as authorized by another ordinance, Nevada County Land Use and Development Code, article 29, section L-II 29.2 (hereafter section 29.2), the county has permitted plaintiff to continue its mining operations. Under section 29.2, when the county adopts a zoning ordinance prohibiting certain activities or “uses,” property owners who are already engaged in those uses may continue to do so, as a “nonconforming use."
Section 29.2 strictly limits the scope of nonconforming uses: they may not be “enlarged or intensified,” “extended to occupy a greater area of land,” or “moved in whole or in part to any other portion of the [property owner’s] land.” Also, any nonconforming use that is “discontinued for a period of one hundred eighty (180) days or more” loses its status as a nonconforming use.3
In 1989, plaintiff submitted a “reclamation plan” to Nevada County to comply with California’s Surface Mining and Reclamation Act of 1975. *583(Pub. Resources Code, § 2710 et seq.; hereafter SMARA.) This state law requires those engaged in surface mining to submit to a local agency, in this case the Nevada County Board of Supervisors, a reclamation plan describing the efforts to be made in minimizing adverse environmental effects resulting from the mining. No mining is permitted unless the agency approves the plan.4
Plaintiff’s reclamation plan is set forth on a form furnished by Nevada County. According to the plan, the hillsides on plaintiff’s property contain 5.000. 000 cubic yards of rock. Plaintiff proposes to remove all of this rock over the course of the next 100 or more years. The form requires those submitting a reclamation plan to describe—by checking the appropriate boxes on the form—the amount of materials that will be mined. Plaintiff checked 2 boxes, indicating that, depending on demand of its customers, it intended to remove between 5,000 to 50,000, or between 50,000 and 250.000, cubic yards per year. Plaintiff expects to remove 1,000,000 cubic yards of “overburden” covering the rock. Most of that material will be used to build access roads needed in the excavation process; 150,000 cubic yards of overburden, described as “soil," will be stored on the property and used in the reclamation process. Implementation of the plan will necessitate drilling and blasting, and will require excavation of plaintiff’s hillsides to a depth of 350 feet.
Both the Nevada County Planning Commission and the Nevada County Board of Supervisors conducted separate hearings to decide whether plaintiff’s reclamation plan should be approved. At those hearings, the following evidence was presented regarding plaintiff’s mining activities.
In 1954, and for many years thereafter, plaintiff’s primary mining activity consisted of harvesting gravel that washed down the Bear River (hereafter also referred to as riverbed mining). These materials were stored on site and sold. To accommodate customers who wanted riverbed gravel mixed with hard rock, plaintiff also operated small quarries on either side of the river to *584extract rock.5 Depending on the needs of its customers, plaintiff sold gravel and rock, or a combination of the two. The record does not disclose how much of the gravel sold by plaintiff was mixed with rock, or how many of plaintiff’s customers bought such a mixture.
Nor does the record show how much gravel plaintiff and its predecessors removed annually from the Bear River. Bill Goss, plaintiff’s plant manager, estimated that during the 18 years he had worked at the site, the total amount of materials harvested from the riverbed and mined from the quarries was roughly 3,000,000 tons. According to Goss, one-fifth of this total (or 600,000 tons) was rock extracted from the quarries and the rest gravel taken from the riverbed. Other evidence, however, showed that a far smaller portion was actually mined from the quarries. Alan Hess, a photogrammetric engineer, estimated, based on aerial photographs of the site, that in the 43 years during which the mining had been conducted (more than twice the length of time during which plant manager Goss had worked for plaintiff), only 266,000 tons of rock had been removed from the Placer County side of the river, and only 72,000 tons (or 45,000 cubic yards) had been quarried from the Nevada County side.
After construction of the Rollins Reservoir Dam, upstream from plaintiff’s property, the amount of gravel washing down the river declined dramatically.6 In early 1986, a flood washed a substantial quantity of sand and gravel over the dam; plaintiff harvested those materials in 1986 and 1987. Thereafter, plaintiff ceased its riverbed mining, but continued to store rock and gravel on the property. Although witnesses for plaintiff asserted that plaintiff continued to operate the quarry,7 neighbors opposed to plaintiff’s reclamation plan provided conflicting evidence. Randall Atkins, who lived near the mine, told the planning commission that he had purchased gravel from plaintiff in the past, but that in recent years he had been unable to do so because, in his words, “there is no operation there.” Atkins’s comments were confirmed by Bill Dickson, who also lived near the mine. According to other witnesses living near the mine, there had been no more than three trucks traveling along the road to the mine in the year and a half preceding the *585hearing before the planning commission. And in a letter dated October 3, 1988, Nevada County Counsel James Curtis stated that he had visited the mine and concluded that “the last time any mining occurred on land was more than three years ago.”
The Nevada County Planning Commission, acting in its capacity as a local agency under SMARA, denied approval of plaintiff’s reclamation plan. As relevant here, the commission also concluded that the mining operations described in the plan exceeded the scope of plaintiff’s nonconforming use under section 29.2, the county ordinance governing nonconforming uses; the commission left open the possibility that plaintiff could continue its mining operations if it obtained a conditional use permit.
The planning commission determined that the mining described in plaintiff’s reclamation plan was not within the scope of plaintiff’s nonconforming use because (1) mining under the proposed plan would violate section 29.2’s requirement that nonconforming uses may not be “enlarged or intensified,” and (2) plaintiff had quarried no rock for a period of more than 180 days and therefore was deemed to have abandoned its right to mine the land.8 Plaintiff appealed the commission’s decision to the Nevada County Board of Supervisors, which upheld the planning commission.
Plaintiff then filed a petition for administrative mandate in the superior court, seeking a judicial determination that the mining described in its permit application was a permissible continuation of its preexisting nonconforming use, and that it could engage in such operations without obtaining a conditional use permit.9 After an independent examination of the administrative record, the superior court ruled that plaintiff had received a fair hearing before the Nevada County Planning Commission and the Board of Supervisors. The court found that (1) the mining described in plaintiff’s reclamation plan was a “substantial expansion and intensification of any previous use of the property,” and that (2) plaintiff had abandoned its right to mine the hillsides on its property. The Court of Appeal affirmed.
II
As a general rule, local governmental entities may use their zoning power to prohibit a property owner from using the property in a specified manner, *586and such restrictions ordinarily will not constitute a “taking” that would entitle the property owner to “just compensation” under the Fifth Amendment to the United States Constitution. (Penn Central Transp. Co. v. New York City (1978) 438 U.S. 104, 125 [57 L.Ed.2d 631, 648-649, 98 S.Ct. 2646].) But “because of the hardship and doubtful constitutionality” of forbidding a property owner from conducting a use that is already ongoing when an ordinance prohibiting that use is enacted, most zoning ordinances permit any such use to continue as a “nonconforming use.” (County of San Diego v. McClurken (1951) 37 Cal.2d 683, 686 [234 P.2d 972].)
A property owner’s right to continue a nonconforming use, however, is a right that is limited, narrowly construed, and subject to ultimate extinction. “[Z]oning legislation looks to the future in regulating district development and the eventual liquidation of nonconforming uses within a prescribed period commensurate with the investment involved. [Citation.] The mere fact that some hardship may thereby be experienced is not controlling, for ‘every exercise of the police power is apt to affect adversely the property interest of somebody.’ ” (Livingston Rock etc. Co. v. County of LA. (1954) 43 Cal.2d 121, 127 [272 P.2d 4].) As a result, “courts throughout the country generally follow a strict policy against [the] extension or enlargement” of nonconforming uses. (County of San Diego v. McClurken, supra, 37 Cal.2d at p. 687; see also City of Los Angeles v. Wolfe (1971) 6 Cal.3d 326, 337 [99 Cal.Rptr. 21, 491 P.2d 813] [“The policy of the law is for elimination of nonconforming uses . . . .”].)
With these principles in mind, I turn to section 29.2, the nonconforming use ordinance at issue, and apply it to the facts of this case.
III
As I have noted previously, section 29.2 provides that a nonconforming use may not “be extended to occupy a greater area of land” and may not “be moved in whole or in part to any other portion” of the land in question. Thus, on its face, section 29.2 seemingly would bar plaintiff from extending its mining activities to any part of its property not being mined when the zoning ordinance prohibiting mining was enacted in 1954.
As applied to mining and similar activities, a prohibition against expanding the use to other portions of the land may be tantamount to prohibiting the use altogether. A leading treatise explains: “Application of the rule that a nonconforming use may not be extended to land not so used prior to the enactment of a restrictive ordinance may work a singular hardship where the use in question involves the removal of natural products from the earth. *587Quarries and sources of topsoil are particularly vulnerable because, by their very nature, they commence on one spot and spread to additional ground as the gravel, coal, or topsoil is exhausted.” (1 Anderson, American Law of Zoning (3d ed. 1986) § 6.52, p. 604, fn. omitted.)
To address this problem, courts in other states have developed what is now known as the diminishing asset doctrine, under which a landowner may not be prohibited from extending an otherwise permissible nonconforming use onto adjacent portions of the owner’s property if the use consists of extracting nonrenewable resources from the earth. (See 1 Anderson, op. cit. supra, § 6.52, pp. 604-605, and cases cited therein.) Before today’s decision by this court, the status of the diminishing asset doctrine in California was somewhat uncertain because only one published decision by a California court, McCaslin v. City of Monterey Park (1958) 163 Cal.App.2d 339 [329 P.2d 522], had addressed the diminishing asset issue.
In McCaslin, the plaintiff mined decomposed granite at a 70-acre site in Monterey Park. The city first enacted a zoning ordinance prohibiting mining, then enacted a second ordinance prohibiting any expansion of the plaintiff’s mine onto adjoining property. The trial court enjoined enforcement of the second ordinance. In affirming that ruling, the Court of Appeal stated: “Defendants assert that. . . plaintiff was limited to excavating that portion of the property already excavated. We do not agree. The very nature and use of an extractive business contemplates the continuance of such use of the entire parcel of land as a whole, without limitation or restriction to the immediate area excavated at the time the ordinance was passed.” (McCaslin v. City of Monterey Park, supra, 163 Cal.App.2d at p. 349.) Although McCaslin did not use the term “diminishing asset doctrine,” the passage I have just quoted indicates McCaslin’s acceptance, in substance, of the principles underlying the doctrine.
The majority in this case embraces the diminishing asset doctrine. In essence, the majority creates a presumption that any local governmental entity enacting a zoning ordinance that permits a property owner to continue to engage in nonconforming uses but prohibits expansion of those uses to other portions of the owner’s property has adopted the diminishing asset doctrine. (Lead opn., ante, at p. 559.) I have no quarrel with this conclusion insofar as it applies to mines that extract materials from the ground; it should *588not, however, apply to a mine that, as here, extracts materials washing down a stream or river.10
Although a number of decisions from other jurisdictions have adopted the diminishing asset doctrine, no court, so far as my research has disclosed, has applied the doctrine to a riverbed mine. (See Hawkins v. Talbot (1957) 248 Minn. 549 [80 N.W.2d 863, 864] [gravel pit]; Stephan & Sons v. Municipality of Anchorage (Alaska 1984) 685 P.2d 98, 99 [56 A.L.R.4th 761] [same]; Gibbons & Reed Company v. North Salt Lake City (1967) 19 Utah 2d 329 [431 P.2d 559, 563] [same]; County of Du Page v. Elmhurst-Chicago Stone Co. (1960) 18 Ill.2d 479 [165 N.E.2d 310, 311] [open pit limestone quarry]; Moore v. Bridgewater Tp. (1961) 69 N.J.Super 1 [173 A.2d 430, 431] [stone quarry]; Smart v. Dane County Bd. of Adjustments (1993) 177 Wis.2d 445 [501 N.W.2d 782, 783] [mine described as “pit”; materials extracted not named]; Syracuse Aggregate Corp. v. Weise (1980) 51 N.Y.2d 278 [434 N.Y.S.2d 150, 414 N.E.2d 651, 652-653] [sand, gravel, and topsoil excavation].) Unlike other mines, the “assets” of a riverbed mine do not “diminish”: the owner can “mine” the same area again and again, removing new sand and gravel that washes downstream. By its very nature, such a mine is not designed to spread over the entire land; rather, the mine is confined to the bed of the body of water on which it is located. As I explained earlier, underlying the creation of the diminishing asset doctrine was the recognition that, in general, mining operations must move from one spot to another, to allow for extraction of materials from additional ground after exhaustion of a previous mining source. That cannot be said of a mining operation that extracts materials washing down a stream or a river, and therefore the diminishing asset doctrine should not apply to such mining.
Furthermore, although the diminishing asset doctrine permits mine operators to extend their mines to portions of their property not previously excavated, the doctrine does not restrict the power of a governmental entity to limit, as was done here, the intensity of the operator’s mining activities. Thus, in this case the doctrine has no bearing on that portion of section 29.2 providing that a nonconforming use may not be “intensified.”
IV
Here, the county planning commission, the county board of supervisors, the trial court, and the Court of Appeal all determined that the excavation *589proposed in plaintiff’s reclamation plan exceeded the scope of plaintiff’s nonconforming use, because it violated section 29.2’s requirement that nonconforming uses may not be “intensified.” They therefore concluded that, without a conditional use permit, plaintiff could not engage in the mining operations described in its reclamation plan.11 They reached this conclusion by a two-step process.
First, they found that plaintiff’s riverbed mining and its rock quarrying were two separate “uses” of its property, rejecting plaintiff’s assertion that all of its mining operations were an indivisible unit. Second, they compared plaintiff’s rock quarrying operation to the quarrying proposed in plaintiff’s reclamation plan, and concluded that the intensity of the quarrying in the reclamation plan greatly exceeded that of plaintiff’s previous quarrying operations.
The lead opinion rejects the first step of that analysis. It asserts that the issue of whether plaintiff’s reclamation plan proposes an intensification of its previous mining activity should be decided by comparing plaintiff’s proposal to the amount mined in plaintiff’s entire operation, including the amount extracted from the river. I disagree.
Although closely related, plaintiff’s riverbed mine and the quarry from which it extracts rock are separate operations that remove different types of materials; neither operation depends on the other for its continued existence. Before construction of the Rollins Reservoir Dam, plaintiff’s mining operation was devoted almost entirely to the removal of gravel from the river. On some occasions, at the request of customers, plaintiff mixed the gravel extracted from the river with rock quarried from the adjacent land. Other customers, however, purchased either gravel only, or rock only. Thus, although plaintiff sometimes combined the rock mined from the quarry with the gravel mined from the river, plaintiff offered no evidence that the continued operation of the quarry was an indispensable part of the riverbed mining operation, or vice versa. Because the riverbed mine and the quarry on the adjacent land produced, in essence, two separate “products” extracted from different parts of the property and sold to different customers, the county board of supervisors and the trial court could properly regard the *590mining of the riverbed and the mining of the quarry as two separate “uses” rather than a single nonconforming use.
The fundamental difference between riverbed mines and quarries, as I have set forth in part III, ante, provides an additional ground for treating them as two separate “uses” instead of a single nonconforming use in deciding whether a change in either operation amounts to an intensification. As I have pointed out, the diminished asset doctrine applies to quarries but not to riverbed mines because riverbed mines are continually replenished when new materials are washed downstream, and operators of such mines therefore need not expand to other portions of their property to continue in operation. Because a quarry needs to expand simply to continue to exist, determining whether such expansion amounts to an intensification or instead is simply a necessary extension of the existing mine presents an issue that is entirely different from deciding whether a riverbed mine’s proposed expansion of operations is an intensification of its existing use. For this reason, it is appropriate for nonconforming use purposes to regard a riverbed mine and a land-based quarry as two separate “uses” rather than a single nonconforming “use.”
To support its conclusion that plaintiff’s riverbed gravel mine and its nearby rock quarry must be viewed as one nonconforming use, the lead opinion, quoting a respected treatise, states: ‘“[0]ne entitled to a nonconforming use has a right to . . . engage in uses normally incidental and auxiliary to the nonconforming use . . . .’ ” (Lead opn., ante, p. 565, quoting 8A McQuillin, Municipal Corporations (3d ed. 1994) § 25.200, p. 89.) The lead opinion appears to suggest that plaintiff’s quarry is a use “normally incidental to and auxiliary to” plaintiff’s riverbed mine, and that the two mines should therefore be treated as an indivisible unit. But here, as I have shown, substantial evidence supports the trial court’s conclusion that plaintiff’s quarry was not just an “auxiliary” to plaintiff’s riverbed mine, but a separate, independent “use."12
The lead opinion also advances the theory that plaintiff’s quarry is an “integral part” of plaintiff’s mining business, which in the past consisted *591primarily of mining the riverbed. (Lead opn., ante, at pp. 565, 568.) It states: “Unless an independent aspect of the business had been discontinued, the use may not be broken down into component parts and vested rights recognized for less than the entire business operation.” (Id. at p. 566, italics added.) In this case, however, plaintiff’s reclamation plan proposes to discontinue “an independent aspect of the business,” namely, its riverbed mining operation. The plan specifically states that “no additional gravel removal is expected in the 100 year flood channel of the Bear River.”13 This means that the riverbed mine will cease to exist. Because plaintiff proposes to discontinue “an independent aspect of the business” (the riverbed mine), even under the lead opinion’s analysis the county board of supervisors and the trial court could break down plaintiff’s mining use into its “component parts.” Accordingly, in determining whether plaintiff’s reclamation plan represents an intensification of plaintiff’s previous mining activities, the county board of supervisors and the trial court could properly ignore the discontinued “component part” (the riverbed mine) and base the intensification determination only on the sole part remaining: the quarry.
For the reasons set forth above, the Nevada County Planning Commission, the Nevada County Board of Supervisors, the trial court, and the Court of Appeal, correctly concluded that plaintiff’s quarry and its riverbed mine are not an indivisible, integrated operation, but instead are two separate uses. Accordingly, in determining whether plaintiff’s reclamation plan, which did not involve riverbed mining, represented a change in the intensity of plaintiff’s nonconforming use, these entities properly compared the intensity of the mining activities plaintiff proposed in the plan to plaintiff’s previous quarrying activities, without consideration of plaintiff’s riverbed mining operations. Based on this comparison, these entities concluded that plaintiff’s reclamation plan proposes a substantial intensification of plaintiff’s previous quarrying activities. As I shall explain, substantial evidence supports this conclusion.
In the 43 years (1946-1989) during which mining has been conducted on plaintiff’s land, a total of roughly 45,000 cubic yards, or roughly 1,000 cubic yards per year, has been removed from the quarry in Nevada County.14 Plaintiff now proposes to quarry between 5,000 and 250,000 cubic yards of rock per year over the next century. Thus, plaintiff seeks authorization to remove rock from its hillsides at a rate that is as much as 250 times greater than plaintiff has taken out in the past.
*592To guide the trial court in its consideration of the intensification issue on remand, the lead opinion states that a “gradual and natural” increase in the volume of a mining operation is not an intensification of the operation, and therefore does not violate section 29.2’s provision that nonconforming uses may not be “intensified.” (Lead opn., ante, at p. 573.) This statement hardly seems consistent with this court’s “strict policy against [the] extension or enlargement” of nonconforming uses (County of San Diego v. McClurken, supra, 37 Cal.2d at p. 687), and the expectation in zoning legislation that nonconforming uses will eventually be extinguished “within a prescribed period commensurate with the investment involved.” (Livingston Rock etc. Co. v. County of L.A., supra, 43 Cal.2d at p. 127.) But even if a “gradual and natural” increase would not violate section 29.2, the Nevada County Board of Supervisors and the trial court could reasonably conclude that the intensification proposed by plaintiff, which includes mining operations on a scale up to 250 times greater than those conducted by plaintiff in the past, is not “gradual and natural.”15
Conclusion
For the reasons set forth above, I would affirm the judgment of the Court of Appeal.
George, J., concurred.
Respondents’ petition for a rehearing was denied February 29, 1996. Mosk, J., Kennard, J., and George, J., were of the opinion that the petition should be granted.

Justice Baxter’s lead opinion has been signed by the Chief Justice and Justice Arabian. A fourth Justice, Justice Werdegar, concurs in Justice Baxter’s opinion, although she has not signed it. Because I see no significant differences between the views expressed in Justice Baxter’s lead opinion and Justice Werdegar’s concurring opinion, I use the term “majority” to refer collectively to Justices Baxter, Arabian, Werdegar, and the Chief Justice. When referring to Justice Baxter’s opinion, I shall call it the “lead opinion.”

As the lead opinion notes, plaintiff acquired some portions of the property at issue after 1954. Without a conditional use permit, plaintiffs may mine these portions of the property only if they were being mined in 1954, when the county prohibited mining. (Lead opn., ante, at pp. 560-564.) Because I have no quarrel with the lead opinion’s treatment of this issue, I do not discuss the facts concerning the points in time at which plaintiff acquired its property.

Section 29.2 provides in full:
“Any use lawfully in existence at the time this Chapter or amendments thereto takes effect, although such use does not conform to the provisions of this Chapter, may continue as follows:
“A. No such use shall be enlarged or intensified. Nor shall any such use be extended to occupy a greater area of land than that occupied at the time of the adoption of this Ordinance. Nor shall any such use be moved in whole or in part to any other portion of the lot or parcel *583of land occupied at the time of the adoption of this Chapter or amendment thereto.
“B. If the nonconforming use is discontinued for a period of one hundred eighty (180) days or more, any following use shall be in conformity with all applicable requirements of this Chapter.”

Plaintiff also submitted a reclamation plan to the Placer County Board of Supervisors for the portion of plaintiff’s property located in Placer County. That board approved plaintiff’s plan.

For convenience, I refer to the substances harvested from the river as “gravel” and the hard rock quarried from the adjacent land as “rock,” although these terms no doubt lack technical precision.

Several witnesses mentioned that the dam was already in existence in 1986, but no evidence was introduced establishing the date on which the dam was completed. The dam was probably built in the early 1980’s.

Notwithstanding the evidence that quarrying activity had occurred on both sides of the river, all witnesses mentioned only one quarry, apparently the one located on the north side of the river, in Nevada County.

Although the planning commission found that plaintiff had abandoned the right to mine the remainder of its land, it determined that plaintiff retained the right to extract gravel from the river.

Plaintiff has also appealed Nevada County’s rejection of plaintiff’s reclamation plan. That appeal, however, was made to the State Mining and Geology Board (which has apparently postponed resolution of the appeal pending the outcome of this litigation), and was not the subject of plaintiff’s petition in the superior court. Thus, the adequacy of plaintiff’s reclamation plan is not at issue in this case.

The lead opinion declines to address whether the diminishing asset doctrine applies to such mines, asserting that it is not an issue in this case. (Lead opn., ante, at p. 542, fn. 6.) But as I shall explain in part IV, post, it is an issue, because it is relevant to the question whether plaintiff’s riverbed mine and its quarry may be viewed separately to determine whether plaintiff proposes an intensification of its use of the property.

The planning commission, the board of supervisors, the trial court, and the Court of Appeal also determined, in the alternative, that plaintiff’s plan required a conditional use permit because plaintiff had abandoned the right to mine the land on its property. Because I conclude that plaintiff’s reclamation plan represented a substantial intensification of plaintiff’s mining operation, and thus necessitated a conditional use permit, I do not address this alternative ground relied on by the planning commission, the board of supervisors, the trial court, and the Court of Appeal.

On a petition for administrative mandate challenging an administrative order that substantially affects a fundamental vested right, as in this case, the trial court must “ ‘exercise its independent judgment on the evidence and find an abuse of discretion if the [administrative] findings are not supported by the weight of the evidence.’ ” (Halaco Engineering Co. v. South Central Coast Regional Com. (1986) 42 Cal.3d 52, 64, fn. 10 [227 Cal.Rptr. 667, 720 P.2d 15], quoting Strumsky v. San Diego County Employees Retirement Assn. (1974) 11 Cal.3d 28, 32 [112 Cal.Rptr. 805,520 P.2d 29].) A reviewing court must uphold the trial court’s findings so long as they are supported by substantial evidence, resolving all factual inferences in favor of the party prevailing in the trial court. (Pasadena Unified Sch. Dist. v. Commission on Professional Competence (1977) 20 Cal.3d 309, 314 [142 Cal.Rptr. 439, 572 P.2d 53].)

Presumably, the reason plaintiff does not expect to continue extracting gravel from the river is that, as a result of the building of the Rollins Reservoir Dam, there is no more gravel to extract.

Additional rock has been quarried from that portion of plaintiff’s property located on the Placer County side of the river.

The lead opinion asserts that “the SMARA application form is not designed for, and alone is not an adequate basis upon which to decide, the question of impermissible intensification.” (Lead opn., ante, at p. 574.) The lead opinion suggests that Nevada County wait until it determines that plaintiff’s mining activities have exceeded the scope of its nonconforming use, after which it can seek injunctive relief. (Id. at pp. 574-575.) But the Nevada County Board of Supervisors’ conclusion that plaintiff’s reclamation plan exceeded the scope of plaintiff’s nonconforming use was based not only on the SMARA application form, but also on the hearings conducted initially by the planning commission and then by the board. The lead opinion’s suggestion is not a good one, either from plaintiff’s perspective or the county’s. It would be much more efficient for plaintiff to determine the scope of its right to mine its property before plaintiff begins the substantial investment in employees and equipment necessary to conduct the operations described in its reclamation plan, than to attempt to do so after such operations have begun. Similarly, the county’s interests will be better served if it can halt illegal activities on plaintiff’s land before those activities have begun.