¶1
Alexander, C.J.
After failing four times to satisfy the Western Washington Growth Management Hearings Board (Board) that it properly designated agricultural lands for conservation under the Growth Management Act (GMA), chapter 36.70ARCW, Lewis County now asks us to reverse the latest Board orders rebuffing its efforts. We conclude that the Board incorrectly defined agricultural land in reviewing Lewis County’s 2003 ordinances. Accordingly, we reverse the Board’s conclusion that the county violated the GMA by focusing on the farm industry’s projected needs, rather than on soil and land characteristics, in designating agricultural lands for conservation. We also remand the case to the Board to determine whether the county’s designations of agricultural land comply with the GMA, using the correct definition of agricultural land.1 We conclude, however, that the Board did not err by invalidat[494]*494ing the ordinances that: (a) allowed nonfarm uses within designated agricultural lands and (b) excluded “farm centers” and farm homes from those lands. Therefore, we partially affirm the Board’s orders.
I
¶2 Lewis County has long struggled to meet GMA requirements to designate and conserve agricultural lands. In June 2000, March 2001, and July 2002, the Board found the county’s efforts noncompliant.
f 3 In response to the Board’s September 8, 2003, deadline to achieve GMA compliance, the county staff prepared a report explaining how it identified agricultural lands to be conserved. The 2003 staff report said that of the 1,117 farms existing in Lewis County as of the 1997 census, only 176 farms had gross sales of $25,000 or more, and only 161 of them were larger than 180 acres. The report also said that of about 150,000 acres eligible for agricultural designation based on soil type, about 50,000 had no recent agricultural activity. The report described a decline in dairies and field crops, an absence of “significant clusters” of organic farms, and a poultry industry constrained by a lack of water rights. Clerk’s Papers (CP) at 242. The report also said no land conservation was needed for the hay and Christmas tree industries because they do not depend on soil, and “[g]rass hay in particular is a marginal operation, in that in good years the return is often barely enough to pay taxes on the property.” Id. at 254. Finally, the staff report said most Lewis County farms are not economically self sufficient and [495]*495therefore need “non farm income” for survival. Id. To address that need, the report recommended allowing each farm to have a “farm center” of up to five acres where rural commercial and industrial uses would be allowed. Id. at 255.
¶4 The Lewis County Planning Commission held public hearings and approved the staff report almost entirely. It recommended that the Lewis County Commission designate 54,500 acres of agricultural land, “appropriate in location and amount to reasonably conserve the land-based needs of the commercial agriculture industry for the foreseeable future.”2 Id. at 283. On September 8, 2003, the Lewis County Commission adopted by ordinance the planning commission findings and most of its recommendations, along with maps designating an agricultural zone of about 54,400 acres. And while prohibiting certain nonfarm land uses, the commission allowed others — including residential subdivisions, home-based businesses, and telecommunication facilities — to be located in agricultural lands as long as they met certain conditions.3 The ordinances designated 13,767 acres of “Class A” farmlands, characterized by prime farm soils, over 40,000 acres of “Class B” farmlands, and “[farmlands of [l]ocal [i]mportance.” Id. at 670. The commission removed some lands from designation because they: (1) had “already been divided,” (2) “lost irrigation rights,” or (3) were “isolated and in areas where land development and potential changes create the potential for conflict and . . . significant change.” Id. at 283. The latter included lands near Interstate 5 where the county wants to attract “major industry.” Id.
¶5 The county’s designation of 54,400 acres of agricultural lands, as compared with 66,000 acres receiving special agricultural tax status and 283,000 acres of land with prime farm soils in Lewis County, was controversial. In [496]*496January 2004, the Board held a hearing to review citizen petitions challenging the county’s 2003 actions and to determine GMA compliance.4 The citizen petitioners, using soil and aerial maps, claimed to identify 140,645 acres that were currently or recently used for agriculture and that should have been conserved. In February 2004, the Board issued a 49-page order concluding that Lewis County still failed to comply with the GMA. The Board reasoned as follows:
The GMA defines the requirements for designating natural resource lands based on the characteristics of the lands. Instead of basing its designation decisions on the characteristics of agricultural land, Lewis County focused its decision-making on its assessment of the needs of the local agricultural industry .... Historically, in Lewis County as well as in other counties, the agricultural industry has changed as the market for agricultural products changed. Agricultural economists are not able to predict which products will be in demand next year, let alone for the foreseeable future. The legislature, therefore, did not tie the designation of agricultural lands to economic conditions which shift unpredictably but to the characteristics of the land. The moving concern underlying the GMA’s requirement for designation and conservation of agricultural lands is to preserve lands capable of being used for agriculture because once gone, the capacity of those lands to produce food is likely gone forever.
Id. at 634. The Board invalidated the ordinances and maps that (a) designated the agricultural lands to be conserved, (b) excluded “ ‘farm centers’ ” and farm homes from designated agricultural lands, (c) allowed nonagricultural uses on the designated lands, and (d) required “ ‘sufficient irrigation capability’ ” for designation as Class A farmland.5 Id. at 674, 675. In a May 2004 order on reconsideration, the Board said that “until the County utilizes a compliant approach . . . , potential agricultural resource lands in the [497]*497rural zones must be preserved from incompatible development so that they will be available for assessment under a compliant approach.”6 Id. at 684.
¶6 Lewis County appealed both 2004 orders to the Lewis County Superior Court. On December 23, 2004, the superior court affirmed the Board’s orders, agreeing with the Board that “the . . . ‘needs of the industry* argument is clearly erroneous” and that “the definition of long-term significance refers to the growing capacity and productivity of the soil.” Id. at 10. We granted review.
II
¶7 The Board is charged with adjudicating GMA compliance and invalidating noncompliant plans and development regulations. RCW 36.70A.280, .302. The Board “shall find compliance” unless it determines that a county action “is clearly erroneous in view of the entire record before the board and in light of the goals and requirements” of the GMA.
Free access — add to your briefcase to read the full text and ask questions with AI
¶1
Alexander, C.J.
After failing four times to satisfy the Western Washington Growth Management Hearings Board (Board) that it properly designated agricultural lands for conservation under the Growth Management Act (GMA), chapter 36.70ARCW, Lewis County now asks us to reverse the latest Board orders rebuffing its efforts. We conclude that the Board incorrectly defined agricultural land in reviewing Lewis County’s 2003 ordinances. Accordingly, we reverse the Board’s conclusion that the county violated the GMA by focusing on the farm industry’s projected needs, rather than on soil and land characteristics, in designating agricultural lands for conservation. We also remand the case to the Board to determine whether the county’s designations of agricultural land comply with the GMA, using the correct definition of agricultural land.1 We conclude, however, that the Board did not err by invalidat[494]*494ing the ordinances that: (a) allowed nonfarm uses within designated agricultural lands and (b) excluded “farm centers” and farm homes from those lands. Therefore, we partially affirm the Board’s orders.
I
¶2 Lewis County has long struggled to meet GMA requirements to designate and conserve agricultural lands. In June 2000, March 2001, and July 2002, the Board found the county’s efforts noncompliant.
f 3 In response to the Board’s September 8, 2003, deadline to achieve GMA compliance, the county staff prepared a report explaining how it identified agricultural lands to be conserved. The 2003 staff report said that of the 1,117 farms existing in Lewis County as of the 1997 census, only 176 farms had gross sales of $25,000 or more, and only 161 of them were larger than 180 acres. The report also said that of about 150,000 acres eligible for agricultural designation based on soil type, about 50,000 had no recent agricultural activity. The report described a decline in dairies and field crops, an absence of “significant clusters” of organic farms, and a poultry industry constrained by a lack of water rights. Clerk’s Papers (CP) at 242. The report also said no land conservation was needed for the hay and Christmas tree industries because they do not depend on soil, and “[g]rass hay in particular is a marginal operation, in that in good years the return is often barely enough to pay taxes on the property.” Id. at 254. Finally, the staff report said most Lewis County farms are not economically self sufficient and [495]*495therefore need “non farm income” for survival. Id. To address that need, the report recommended allowing each farm to have a “farm center” of up to five acres where rural commercial and industrial uses would be allowed. Id. at 255.
¶4 The Lewis County Planning Commission held public hearings and approved the staff report almost entirely. It recommended that the Lewis County Commission designate 54,500 acres of agricultural land, “appropriate in location and amount to reasonably conserve the land-based needs of the commercial agriculture industry for the foreseeable future.”2 Id. at 283. On September 8, 2003, the Lewis County Commission adopted by ordinance the planning commission findings and most of its recommendations, along with maps designating an agricultural zone of about 54,400 acres. And while prohibiting certain nonfarm land uses, the commission allowed others — including residential subdivisions, home-based businesses, and telecommunication facilities — to be located in agricultural lands as long as they met certain conditions.3 The ordinances designated 13,767 acres of “Class A” farmlands, characterized by prime farm soils, over 40,000 acres of “Class B” farmlands, and “[farmlands of [l]ocal [i]mportance.” Id. at 670. The commission removed some lands from designation because they: (1) had “already been divided,” (2) “lost irrigation rights,” or (3) were “isolated and in areas where land development and potential changes create the potential for conflict and . . . significant change.” Id. at 283. The latter included lands near Interstate 5 where the county wants to attract “major industry.” Id.
¶5 The county’s designation of 54,400 acres of agricultural lands, as compared with 66,000 acres receiving special agricultural tax status and 283,000 acres of land with prime farm soils in Lewis County, was controversial. In [496]*496January 2004, the Board held a hearing to review citizen petitions challenging the county’s 2003 actions and to determine GMA compliance.4 The citizen petitioners, using soil and aerial maps, claimed to identify 140,645 acres that were currently or recently used for agriculture and that should have been conserved. In February 2004, the Board issued a 49-page order concluding that Lewis County still failed to comply with the GMA. The Board reasoned as follows:
The GMA defines the requirements for designating natural resource lands based on the characteristics of the lands. Instead of basing its designation decisions on the characteristics of agricultural land, Lewis County focused its decision-making on its assessment of the needs of the local agricultural industry .... Historically, in Lewis County as well as in other counties, the agricultural industry has changed as the market for agricultural products changed. Agricultural economists are not able to predict which products will be in demand next year, let alone for the foreseeable future. The legislature, therefore, did not tie the designation of agricultural lands to economic conditions which shift unpredictably but to the characteristics of the land. The moving concern underlying the GMA’s requirement for designation and conservation of agricultural lands is to preserve lands capable of being used for agriculture because once gone, the capacity of those lands to produce food is likely gone forever.
Id. at 634. The Board invalidated the ordinances and maps that (a) designated the agricultural lands to be conserved, (b) excluded “ ‘farm centers’ ” and farm homes from designated agricultural lands, (c) allowed nonagricultural uses on the designated lands, and (d) required “ ‘sufficient irrigation capability’ ” for designation as Class A farmland.5 Id. at 674, 675. In a May 2004 order on reconsideration, the Board said that “until the County utilizes a compliant approach . . . , potential agricultural resource lands in the [497]*497rural zones must be preserved from incompatible development so that they will be available for assessment under a compliant approach.”6 Id. at 684.
¶6 Lewis County appealed both 2004 orders to the Lewis County Superior Court. On December 23, 2004, the superior court affirmed the Board’s orders, agreeing with the Board that “the . . . ‘needs of the industry* argument is clearly erroneous” and that “the definition of long-term significance refers to the growing capacity and productivity of the soil.” Id. at 10. We granted review.
II
¶7 The Board is charged with adjudicating GMA compliance and invalidating noncompliant plans and development regulations. RCW 36.70A.280, .302. The Board “shall find compliance” unless it determines that a county action “is clearly erroneous in view of the entire record before the board and in light of the goals and requirements” of the GMA. RCW 36.70A.320(3). To find an action “clearly erroneous,” the Board must have a “firm and definite conviction that a mistake has been committed.” Dep’t of Ecology v. Pub. Util. Dist. No. 1 of Jefferson County, 121 Wn.2d 179, 201, 849 P.2d 646 (1993). On appeal, we review the Board’s decision, not the superior court decision affirming it. King County v. Cent. Puget Sound Growth Mgmt. Hearings Bd., 142 Wn.2d 543, 553, 14 P.3d 133 (2000) (hereinafter referred to as Soccer Fields). “ We apply the standards of RCW 34.05 directly to the record before the agency, sitting in the same position as the superior court.’ ” Id. (quoting City of Redmond v. Cent. Puget Sound Growth Mgmt. Hearings Bd., 136 Wn.2d 38, 45, 959 P.2d 1091 (1998) (hereinafter referred to as Benaroya I)).
[498]*498¶8 The legislature intends for the Board “to grant deference to counties and cities in how they plan for growth, consistent with the requirements and goals of” the GMA. RCW 36.70A.3201. But while the Board must defer to Lewis County’s choices that are consistent with the GMA, the Board itself is entitled to deference in determining what the GMA requires. This court gives “substantial weight” to the Board’s interpretation of the GMA. Soccer Fields, 142 Wn.2d at 553.7
¶9 Under the Administrative Procedure Act (APA), chapter 34.05 RCW, a court shall grant relief from an agency’s adjudicative order if it fails to meet any of nine standards delineated in RCW 34.05.570(3). Here, Lewis County asserts that the Board erroneously applied the law, warranting relief under RCW 34.05.570(3)(d), and engaged in an unlawful decision-making process. RCW 34.05-.570(3)(c). The burden of demonstrating that the Board erroneously applied the law or failed to follow prescribed procedure is on the party asserting error. Soccer Fields, 142 Wn.2d at 553. Our review of issues of law under RCW 34.05.570(3)(d) is de novo. Thurston County v. Cooper Point Ass’n, 148 Wn.2d 1, 8, 57 P.3d 1156 (2002). “On mixed questions of law and fact, we determine the law independently, then apply it to the facts as found by the agency.” Id. (citing Hamel v. Employment Sec. Dep’t, 93 Wn. App. 140, 145, 966 P.2d 1282 (1998), review denied, 137 Wn.2d 1036 (1999)).
Ill
flO Under the GMA, Lewis County must designate “[a]gricultural lands that are not already characterized by [499]*499urban growth and that have long-term significance for the commercial production of food or other agricultural products.” RCW 36.70A.170(l)(a). In addition, the county must adopt development regulations “to assure the conservation of” those agricultural lands designated under RCW 36-.70A.170. RCW 36.70A.060(1).8 The parties in this case offer contrary definitions of the lands subject to these requirements. As a threshold matter, then, we must identify the correct definition of “agricultural lands” under the GMA.
¶11 Lewis County designated agricultural lands based on its own definition: “those lands necessary to support the current and future needs of the agricultural industry in Lewis County, based upon the nature and future of the industry as an economic activity and not on the mere presence of good soils.” CP at 418. The Board called the county’s definition clearly erroneous, saying, “We note that throughout the GMA and the court decisions construing it the focus is on the nature of the land, not on the nature of the agricultural industry that is using the land at any given time.” Id. at 640. The Board also said “[t]he GMA calls for designation of agricultural lands based on characteristics of the land” that affect long-term production capability. Id. But to be guided strictly by the physical nature of the land would stifle economic development in counties like Lewis, which have a significant amount of potentially good farmland, much of which is unproductive. For reasons set forth below, we conclude that the Board’s and county’s definitions of agricultural land are both incorrect.
¶12 The GMA defines agricultural land as “land primarily devoted to the commercial production of horticultural, viticultural, floricultural, dairy, apiary, vegetable, or animal products or of berries, grain, hay, straw, turf, seed, Christmas trees ... or livestock, and that has long-term commercial significance for agricultural production.” RCW 36-[500]*500.70A.030(2). Thus, the legislature established that agricultural lands are those which (1) are “primarily devoted to” commercial agricultural production and (2) have “long-term commercial significance” for such production. RCW 36.70A.030(2). We now turn to what these terms mean.
¶13 This court previously addressed the meaning of the term “primarily devoted to” in Benaroya I,9 a case in which landowners challenged designation of their land as agricultural. We said there that land is primarily “ ‘devoted to’ ” commercial agricultural production “if it is in an area where the land is actually used or capable of being used for agricultural production” and that a landowner’s intended use of land is not conclusive. Benaroya I, 136 Wn.2d at 53.
¶14 In the present case, the Board relied partly on the aforementioned language in concluding that Lewis County improperly excluded from designation those lands that are “capable of being used” for farm production. CP at 637. But Benaroya I dealt only with whether land is “ ‘primarily devoted to’ ” farming under RCW 36.70A.030. Benaroya I, 136 Wn.2d at 49. The other question in designating agricultural land, neglected by the Board in this case, is whether land also has “long-term commercial significance” for farm production.
f 15 The GMA says that long-term commercial significance “includes the growing capacity, productivity, and soil composition of the land for long-term commercial production, in consideration with the land’s proximity to population areas, and the possibility of more intense uses of the land.” RCW 36.70A.030(10) (emphasis added). Thus, coun[501]*501ties must do more than simply catalog lands that are physically suited to farming. They must consider development prospects (the “possibility of more intense uses”) in determining if land has the enduring commercial quality needed to fit the agricultural land definition.
¶16 While this court has not previously interpreted RCW 36.70A.030(10), we approve of the approach used by the Court of Appeals in Manke Lumber Co. v. Diehl, 91 Wn. App. 793, 959 P.2d 1173 (1998), review denied, 137 Wn.2d 1018 (1999). In Manke, Mason County challenged a Board decision to invalidate its designation of forest lands, subject to the same GMA conservation requirements as agricultural lands. In holding that the Board erred, the court relied largely on WAC 365-190-050,10 a Washington Department of Community, Trade and Economic Development regulation designed to guide counties in determining which agricultural and forest lands have “long-term commercial significance.” That regulation says that counties
shall also consider the combined effects of proximity to population areas and the possibility of more intense uses of the land as indicated by:
(a) The availability of public facilities;
(b) Tax status;
(c) The availability of public services;
(d) Relationship or proximity to urban growth areas;
(e) Predominant parcel size;
(f) Land use settlement patterns and their compatibility with agricultural practices;
(g) Intensity of nearby land uses;
(h) History of land development permits issued nearby;
(i) Land values under alternative uses; and
(j) Proximity of markets.
[502]*502WAC 365-190-050(1).11 The court in Manke determined that the Board misapplied the GMA and that the county could limit forest land designations to parcels of at least 5,000 acres that have a forest tax classification because the guidelines allow consideration of “predominant parcel size” and “tax status” in determining long-term significance. See Manke, 91 Wn. App. at 807-08.
f 17 In sum, based on the plain language of the GMA and its interpretation in Benaroya I, we hold that agricultural land is land: (a) not already characterized by urban growth (b) that is primarily devoted to the commercial production of agricultural products enumerated in RCW 36.70A.030(2), including land in areas used or capable of being used for production based on land characteristics, and (c) that has long-term commercial significance for agricultural production, as indicated by soil, growing capacity, productivity, and whether it is near population areas or vulnerable to more intense uses. We further hold that counties may consider the development-related factors enumerated in WAC 365-190-050(1) in determining which lands have long-term commercial significance. We, therefore, remand this case for the Board to apply the correct definition of agricultural land in determining whether Lewis County’s 2003 ordinances complied with RCW 36.70A.170(1).
IV
¶18 The respondent citizens in this case argue that “[n] owhere in the GMA or in the implementing WACs is there authority to limit agricultural resource lands designations using an industry needs assessment.” Br. of Resp’ts [503]*503at 10. While it is true that no statute specifically authorizes counties to weigh industry needs above all other considerations in designating and conserving agricultural land, this does not mean the GMA prohibits such an approach. As noted above, the GMA’s stated intent is to recognize the “broad . . . discretion” of counties to make choices within its confines. RCW 36.70A.3201. Because the GMA does not dictate how much weight to assign each factor in determining which farmlands have long-term commercial significance, and because RCW 36.70A.030(10) includes the possibility of more intense uses among factors to consider, it was not “clearly erroneous” for Lewis County to weigh the industry’s anticipated land needs above all else. If the farm industry cannot use land for agricultural production due to economic, irrigation, or other constraints, the possibility of more intense uses of the land is heightened. RCW 36-.70A.030(10) permits such considerations in designating agricultural lands. Indeed, Manke involved some of the same considerations cited in the Lewis County staff report: undersized parcels and possible conflicts with nearby development. Therefore, the Board erred in concluding that Lewis County violated the GMA by designating agricultural lands based on the local farm industry’s anticipated needs.
¶19 However, we do not decide whether Lewis County, in focusing on the needs of the local agriculture industry, went beyond the considerations permitted by WAC 365-190-050 and RCW 36.70A.030 in designating agricultural lands. Unfortunately, Lewis County’s briefs do not explain the extent to which the county applied the specified factors.12 [504]*504And while Lewis County Ordinance 1179C does spell out in detail how the county considered WAC 365-190-050 factors in mapping agricultural lands,13 the record does not indicate whether the county used permissible criteria in other decisions not explicitly tied to the WAC factors. For example, in not designating Christmas tree farms as agricultural land because they do not depend on a particular soil type, the county could have been considering the soil composition factor listed in RCW 36.70A.030(10). But in light of the Christmas tree industry’s relatively robust $19.8 million in annual sales, it is not apparent why Lewis County would “consider” soil in this way, excluding productive tree farms from designated agricultural lands simply because they don’t need the types of prime soil that other farm sectors need. Thus, upon remand, when the Board reviews whether Lewis County properly designated agricultural lands, the inquiry should include whether the county’s decisions were “clearly erroneous” in light of the considerations outlined in RCW 36.70A.030 or WAC 365--190-050.
V
¶20 While most of the county’s designation decisions at least possibly could have been based on per[505]*505missible criteria,14 we note one exception. In excluding “farm centers” and farm homes from designated agricultural lands,15 the county sought “to serve the farmer’s nonfarm economic needs.” Lewis County’s Am. Opening Br. at 30. Serving the farmer’s “nonfarm” economic needs is not a logical or permissible consideration in designating agricultural lands under the GMA. That is because it is a goal in and of itself, not a characteristic of farmland to be evaluated in determining whether such land has long-term commercial significance. A farmer’s presumed need for “nonfarm” income does not necessarily relate to soil, productivity, or growing capacity under RCW 36.70A.030(10), nor to proximity to population areas or the possibility of more intense uses of land. It has to do only with the farmer’s bottom line. And while we share Lewis County’s concern for the struggles farmers often face, we note that the GMA is not intended to trap anyone in economic failure, as evidenced by the mandate to conserve only those farmlands with long-term commercial significance. The problem with the county’s approach is that any farmer could convert any five acres of farmland to more profitable uses, even if such conversion would remove perfectly viable fields from production. Thus it was clearly erroneous for Lewis County to exclude from designated agricultural lands up to five acres on every farm, without regard to soil, productivity, or other specified factors in each farm area.16 Accordingly, we affirm the Board’s invalidation of the blanket exclusion of five-acre farm [506]*506centers and farm homes from designated agricultural lands.
VI
¶21 Having discussed whether Lewis County properly designated lands under RCW 36.70A.170, we now turn to the RCW 36.70A.060 duty to conserve designated lands. The GMA says in relevant part: “Each county. . . shall adopt development regulations ... to assure the conservation of agricultural. . . lands designated under RCW 36.70A.170.” RCW 36.70A.060(1).
A county. . . may use a variety of innovative zoning techniques in areas designated as agricultural lands .... The . . . techniques should be designed to conserve agricultural lands and encourage the agricultural economy. A county . . . should encourage nonagricultural uses to be limited to lands with poor soils or otherwise not suitable for agricultural purposes.
RCW 36.70A. 177(1) (emphasis added).
[TJechniques a county . . . may consider include . . .
(a) Agricultural zoning, which limits the density of development and restricts or prohibits nonfarm uses of agricultural land . . .
(b) Cluster zoning . . .
(c) Large lot zoning . . .
[507]*507(d) [ ]/quarter zoning . . .
(e) Sliding scale zoning ....
RCW 36.70A. 177(2). Thus, counties may choose how best to conserve designated lands as long as their methods are “designed to conserve agricultural lands and encourage the agricultural economy.” RCW 36.70A.177(1).
¶22 Lewis County contends that the Board ignored RCW 36.70A.177 and mandated that all agricultural land be zoned for agriculture only, thereby imposing a “per se prohibition” on all nonagricultural uses there. Lewis County’s Am. Opening Br. at 33. But as the respondent citizens correctly noted, the Board orders contain no such prohibition. Br. of Resp’ts at 24. Rather, the Board concluded that the nonfarm uses allowed within farmlands, including mining, residential subdivisions, telecommunications towers and public facilities: (a) “are not limited in ways that would ensure that they do not impact resource lands and activities negatively” and (b) substantially interfere with achieving the GMA goal of maintaining and enhancing the agricultural industry. CP at 676. Furthermore, the Board found that the zoning failed to conserve agricultural land as required by RCW 36.70A.060. For example, the Board found that: (a) “[t]he failure to regulate farm housing to conserve agricultural prime soils and to prevent residential densities inconsistent with agriculture fails to conserve agricultural lands,” (b) “[cjlustered residential subdivisions as currently allowed in the 13,767 acres of Class A Farmlands are not designed to ensure conservation of agricultural lands and encourage the agricultural economy,” and (c) “the requirement that these uses not detract from the overall productivity of the resource activity is not sufficient protection.” CP at 672. That is different from requiring a particular form of zoning or flatly prohibiting all nonfarm uses. In sum, Lewis County has not been stripped of the ability to use innovative zoning techniques pursuant to RCW 36.70A.177, as it contends. Rather, in invalidating the Lewis County ordinance allowing nonfarm uses of agricultural lands, the Board was simply making sure that the [508]*508county’s zoning methods are actually “designed to conserve agricultural lands and encourage the agricultural economy” as required by RCW 36.70A.177(1).17
¶23 The county also argued that the Board failed to heed this court’s decision in Soccer Fields, 142 Wn.2d 543, which involved whether soccer fields could be located on agricultural lands. Lewis County’s Am. Opening Br. at 31-32. The county contends that the Soccer Fields test is whether a nonagricultural use “unreasonably” prevents agricultural land “from being used for its intended purpose” or “defeat[s]” the county’s ability to maintain and enhance the farm industry. Id. at 32. That is not the test. This court said, “In order to constitute an innovative zoning technique consistent with the overall meaning of the Act, a development regulation must satisfy the Act’s mandate to conserve agricultural lands for the maintenance and enhancement of the agricultural industry.” Soccer Fields, 142 Wn.2d at 560. “After properly designating agricultural lands .. . the County may not then undermine the Act’s agricultural conservation mandate by adopting ‘innovative’ amendments that allow the conversion of entire parcels of prime agricultural soils to an unrelated use.” Id. at 561. The court concluded that the soccer field zoning was noncompliant because it “would result in a long-term removal” of agricultural land from agricultural production, possibly never returning to agricultural use. Id. at 562. Thus, a zoning technique that allows nonfarm uses on designated agricultural lands satisfies the Soccer Fields test if it does not undermine the GMA mandate to conserve [509]*509agricultural lands for the maintenance and enhancement of the farm industry.
¶24 Applying the Soccer Fields test to this case, the question is whether Lewis County’s ordinance allowing residential subdivisions and other nonfarm uses within designated agricultural lands undermined the GMA conservation requirement. This is a question of law, and we give “substantial weight” to the Board’s interpretation of the GMA. Id. at 553. In concluding that Lewis County’s permitting of nonfarm uses could “impact resource lands and activities negatively” and therefore substantially interferes with maintaining and enhancing the farm industry, the Board essentially interpreted the GMA to prohibit negative impacts on agricultural lands and activities. CP at 676. That is consistent with the RCW 36.70A.060 directive to conserve designated agricultural lands, the RCW 36.70A-.020(8) goal of maintaining and enhancing the agricultural industry, and the Soccer Fields holding that innovative zoning may not undermine conservation. Therefore, the Board did not err in holding that the nonfarm uses of agricultural lands failed to comply with the GMA requirement to conserve designated agricultural lands.
VII
¶25 In conclusion, as explained above, we reverse the Board’s decision that Lewis County may not designate agricultural lands based on the local farm industry’s projected land needs. If the State wants to conserve all land that is capable of being farmed without regard to its commercial viability, it may buy the land.
¶26 We also remand the case for the Board to apply the correct definition of agricultural land, taking into account whether the county used permissible criteria. However, we affirm the Board’s invalidation of the exclusion of farm homes and farm centers from designated agricultural lands because “serving the farmer’s nonfarm economic needs” is [510]*510not a permissible consideration. We also affirm the Board’s invalidation of nonfarm uses within agricultural lands.18
C. Johnson, Madsen, Bridge, Owens, and Fairhurst, JJ., concur.