Opinion ID: 1261848
Heading Depth: 2
Heading Rank: 1

Heading: Rational Method

Text: Speedway argues the circuit court erred by affirming the Board's decision that the ALJ erred by concluding the rational method was appropriately used to calculate stormwater runoff rates. It claims the applicable regulation provides OCRM with the flexibility to permit use of the rational method even when the project site is greater than 20 acres. Speedway further claims there is substantial evidence in the record which supports use of the rational method for its project and, therefore, OCRM properly applied its discretion to grant the permit application which used this method. We agree. The purpose of the Stormwater Act is to reduce the adverse effects of stormwater runoff and sediment and to safeguard property and the public welfare by strengthening and making uniform the existing stormwater management and sediment control program. Act No. 51, 1991 Acts 167. In keeping with this purpose, unless otherwise exempted, a person who intends to engage in a land disturbing activity must first submit a stormwater management and sediment control plan to the appropriate implementing agency and obtain a permit to proceed. § 48-14-30. South Carolina Regulation 72-307 (Supp.2001) sets forth the design criteria, minimum standards, and specifications for projects requiring a stormwater management and sediment control plan. Preliminarily, Regulation 72-307(C) provides as follows: Specific requirements for the permanent stormwater management and sediment control plan approval process include, but are not limited to, the following items. The appropriate plan approval agency may modify the following items for a specific project or type of project. (Underline added). Thereafter, the regulation lists twelve items as specific requirements for the permanent stormwater management portion of the plan. Item two follows: (2) All hydrologic computations shall be accomplished using a volume based hydrograph method acceptable to the Commission. The storm duration for computational purposes for this method shall be the 24-hour rainfall event, SCS [7] distribution with a 0.1 hour burst duration time increment. The rational and/or modified rational methods are acceptable for sizing individual culverts or stormdrains that are not part of a pipe network or system and do not have a contributing drainage area greater than 20 AC. The storm duration for computational purposes for this method shall be equal to the time of concentration of the contributing drainage area or a minimum of 0.1 hours, whichever is less. (Underline added). [8] At the administrative hearing, Hadstate's expert witnesses testified it was inappropriate to use the rational method to calculate runoff from the 61 acre tract. The witnesses explained the rational method is only acceptable for use with small watersheds as it assumes the entire area contributes to stormwater flow, thereby losing its accuracy as areas increase in size. Speedway's expert witnesses, including one employee of OCRM, testified the rational method was an appropriate model for the expected stormwater flow from the site. These witnesses explained the rational method suited this project because there was overall uniformity (very gentle slopes, no subwatersheds) in the watershed site. The OCRM witness testified that, on a case by case basis, OCRM permitted other applicants with a contributing drainage area greater than 20 acres to use the rational method. In permitting use of the rational method, the witness explained she relied on the South Carolina Stormwater Management and Sediment Review course materials which approve use of the rational method for contributing watersheds of up to 200 acres and a N.C. State publication which suggests use of the rational method for a watershed of up to 300 acres. Another OCRM expert witness testified he reviewed the rational method calculations conducted by Speedway's professional engineer and concluded they were appropriate. The ALJ concluded the rational method model, recognized as reliable in various fields for designing storm drainage systems in excess of 20 acres, was properly utilized in Speedway's permit application. The Board, however, concluded OCRM and the ALJ misinterpreted and misapplied Regulation 72-307(C)(2). It held the regulation specifically restricts the use of the rational method for hydrologic computations to sites much smaller than [Speedway's] site, and was used improperly in evaluating this application. The circuit court agreed with the Board. The scope of judicial review of agency decisions is governed by S.C.Code Ann. § 1-23-380(A)(6) (Supp.2001). [T]he construction of a statute by the agency charged with its administration will be accorded the most respectful consideration and will not be overruled absent compelling reasons. Dunton v. South Carolina Bd. of Examiners in Optometry, 291 S.C. 221, 223, 353 S.E.2d 132, 133 (1987). Where the terms of the statute are clear, the court must apply those terms according to their literal meaning. Paschal v. State Election Comm'n, 317 S.C. 434, 436, 454 S.E.2d 890, 892 (1995). An appellate court cannot construe a statute without regard to its plain meaning and may not resort to a forced interpretation in an attempt to expand or limit the scope of a statute. Berkebile v. Outen, 311 S.C. 50, 426 S.E.2d 760 (1993). The plain language of Regulation 72-307(C)(2) provides that the rational and/or modified rational methods are, without qualification, acceptable methods for sizing individual culverts or stormdrains which are not part of a pipe network or system and do not have a contributing drainage area greater than 20 acres. The regulation does not state the converse: that the rational and/or modified rational methods are unacceptable for sites in excess of 20 acres. Instead, the regulation provides that, where appropriate, the rational and/or modified rational methods may be utilized. The prefatory comment to Regulation 72-307(C), specifically permitting the plan approval agency to modify the hydrograph method for a particular project, is fully consistent with Regulation 72-307(C)(2). While the Court typically defers to the Board's construction of its own regulation, where, as here, the plain language of the regulation is contrary to the Board's interpretation, the Court will reject its interpretation. Richland County School Dist. Two v. South Carolina Dept. of Educ., 335 S.C. 491, 517 S.E.2d 444 (Ct.App.1999) (court rejected agency's statutory construction where plain meaning of statute provided compelling reason to reject agency's interpretation). We conclude the Board erred by construing Regulation 72-307(C)(2) as prohibiting use of the rational method model for calculating peak stormwater runoff for sites in excess of 20 acres. [9] Accordingly, the circuit court erred by affirming the Board's decision on this issue. See § 1-23-380(A)(6) (court may reverse decision if substantial rights of appellant have been prejudiced because agency conclusions are affected by error of law).