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HomeMy WebLinkAboutSDP201000054 Legacy Document 2010-09-15ALBEMARLE COUNTY PLANNING STAFF REPORT SUMMARY Project Name: SDP201000054- Norman Staff: Elizabeth M. Marotta, Senior Planner and Phil Ourada Critical Slopes Waiver Custer, Engineer Planning Commission Public Hearing: Board of Supervisors Hearing: September 14, 2010 Not applicable Owners: Norman L. Ourada and Margaret Applicant: Norman L. Ourada Rose Byrne Acreage: 2.00 Rezone from: Not applicable Special Use Permit for: Not applicable TMP: Tax Map 88 Parcel 14A By -right use: RA, Rural Areas Location: Red Hill Heights Road [Attachment B], approximately 315' northwest of its intersection with Red Hill Depot Road [State Route 642]. Magisterial District: Samuel Miller Proffers /Conditions: N/A Requested # of Dwelling Lots: N/A DA — RA — X Proposal: Building site modification request, Comp. Plan Designation: Rural Areas 4 in Rural per Section 18 -4.2, to allow +/- 9,000 square Areas feet of critical slopes disturbance and the location of a building site within critical slopes. Character of Property: Combination of Use of Surrounding Properties: Residential, wooded and cleared; previously developed for wooded. a mobile home (now removed) and drainfield (now abandoned). Factors Favorable: Factors Unfavorable: 1. Allows house to be located out of the 1. Total soil loss would likely be greater than if drainage -way. building site were located out of critical 2. Allows a new septic system to be slopes. permitted by the Health Department; 2. Construction of a diversion channel could Health Department will not permit direct drainage water around the house existing drainfield to be used. foundation if house must be located in the 3. Would likely not result in any more soil southeast corner of the site, out of critical loss than many other projects in the slopes. County that do not require critical slopes waivers. RECOMMENDATION: Staff finds that the factors favorable outweigh the unfavorable factors; Staff recommends APPROVAL of the building site modification request. STAFF PERSON: Elizabeth M. Marotta, Senior Planner and Phil Custer, Engineer PLANNING COMMISSION: September 14, 2010 AGENDA TITLE: SDP201000054- Norman Ourada, Critical Slopes Waiver APPLICANT: Norman L. Ourada PROPERTY OWNER(S): Norman L. Ourada and Margaret Rose Byrne APPLICANT'S PROPOSAL: Modification of Sec. 18 -4.2.1 to allow the building site to be located on critical slopes. The applicant's proposal is to allow 9,000 square feet of disturbance to locate house and septic on critical slopes [Attachments A, E]. If the non - critical slopes area of the site is found to be not a satisfactory building site, the driveway would be exempt per Sec. 18- 4.2.6.c. COMPREHENSIVE PLAN: The Comprehensive Plan designates this property as Rural Areas 4 in Rural Areas. REASON FOR PLANNING COMMISSION REVIEW: Sec. 18 -4.2.1 requires the building site (which includes the house and associated drainfields) be located out of critical slopes. The subject property does contain a building site that is out of critical slopes, however there is an existing abandoned drainfield in this building site that the Virginia Department of Health will not permit the new house to use [Attachments I, H]. In addition, the existing building site is located in a drainage -way, and the applicant wishes to locate the house outside of the drainage -way. Because the drainfield must be located within the building site, and there is not another suitable area outside of critical slopes for a new drainfield, and because the existing building site is in a drainage -way, the applicant is requesting a waiver so that he may construct a home and drainfield on the property. The Health Department has approved the proposed drainfield location on critical slopes [Attachment K], and the applicant has provided a certified letter from an engineer vouching for the unsuitability of the building site for a house [Attachment J]. PLANNING AND ZONING HISTORY: None CRITICAL SLOPES MODIFICATION: The request for a modification has been reviewed for both the Engineering and Planning aspects of the critical slopes regulations. Section 4.2.3.2 of the Zoning Ordinance restricts earth- disturbing activity on critical slopes, while Section 4.2.5(a) allows the Planning Commission to waive this restriction. The applicant has submitted a request and justification for the waiver [Attachment A], and staff has analyzed this request to address the provisions of the ordinance. Critical slopes cover approximately 1.18 acres, or approximately 59% percent of the site. 0.21 acres, or 17.8% of critical slopes on the site, are included in this request [Attachment C]. The requested critical slopes are naturally - occurring. Staff has reviewed this waiver request with consideration for the concerns that are set forth in Section 4.2 of the Zoning Ordinance, entitled "Critical Slopes." A request to allow disturbance of critical slopes must be reviewed in accord with the requirements of Section 4.2.5. This section requires a two part analysis. Section 4.2.5(a)(1 -2) is a review of the technical performance standards. If these technical standards are not met the disturbance of critical slopes cannot be approved by the Planning Commission. If these technical standards are met the Planning Commission may then consider the disturbance of critical slopes. The criteria for the Planning Commission's review of the disturbance of critical 2 slopes are found in Section 4.2.5(a)(3). Staff presents the analysis of the request to disturb critical slopes in two parts. PART I REVIEW OF REQUIREMENTS OF SECTION 4.2.5: Section 4.2.5 establishes the review process and criteria for granting a waiver of Section 4.2.1. The following comments by Staff address the provisions of Section 4.2.5(a): County Engineer's review of the technical performance standards: The critical slope areas are naturally - occurring. The critical slope disturbances are in the form of: Areas Acres Total site area 2.0 acres Area of critical slopes 1.18 acres 51,500 SF +/- 59% of the site Total critical slopes disturbed 0.21 acres 17.8% of critical slopes Note: These numbers do not include any disturbance necessary to establish a well and running the waterline to the house, as this disturbance is believed to be negligible. Below, each of the concerns of Zoning Ordinance Chapter 18 Section 4.2.5(a)(1 -2) are addressed: Section 4.2.5(a)(1): "rapid and /or large scale movement of soil and rock' : The USDA soil classification for all areas of the parcel is Chester very stony loam, 15 to 25 percent slopes (15D). Because of the steepness of the grade, the USDA soil survey notes that the hazard for erosion of this soil as severe. In order for any building permit to be approved in the rural area, the property owner is required to sign an Agreement in Lieu of Plan as provided in Virginia ESC Law. This agreement commits the applicant to follow all state ESC standards during construction. With agreements, however, ESC bonds are not held by the county and site inspection is more infrequent due to the wide dispersion of rural area building permits. The applicant has included in the waiver request package a letter from a professional engineer, Mr. Michael Craun, which asserts that construction in the flatter (15% grade), southeast corner of the site would cause more erosion because the earth disturbance would occur in an area where water from the uphill lands concentrate. While this is a noteworthy concern, the County Engineer believes this disadvantage can be mitigated by constructing a channel on the uphill side of the house to bypass this flow. A channel or low point on the uphill side of the house will be needed in both building locations, but the channel would need to be larger if the lower corner of the property was the area of house construction. In the opinion of the County Engineer, comparing the potential soil loss of the two slopes (15% and 28 %) is more critical than the construction of the channel around the house when evaluating potential soil loss. The Revised Universal Soil Loss Equation (RUSLE) is a formula endorsed by the USDA that is primarily used to estimate soil loss on tilled farmland. Though, it can be applied to construction sites as well. The equation is represented below: A= R *K *L *S *C *P where, A = Net Detachment (i.e. Soil Loss) R = Erosivity Factor K = Soil Erodibility Factor L = Slope Length (ft) S = Slope Steepness (ft/ft) C = Cover - Management Factor P = Supporting Practices When applying this equation to the two potential building sites being analyzed in this application, the values R, K, C, and P will essentially be the same (assuming an upstream channel was installed properly). So, the equation reduces to: Soil Loss = X * Slope * Length where, X = a constant (RKCP) The average grade at the current proposed location of the building ( -28 %) is almost twice as steep as the alternative at the lower end of the site (15 %). Consequently, the length of slope disturbed at the current proposed location will be slightly longer. So, according to the RUSLE, the soil loss is estimated to be twice as much at the current proposed building site than if the area of the property with flatter slopes were to be the site of the house. The County Engineer acknowledges that some additional soil loss would result from the construction of the bypass channel. But the amount is impossible to quantify or estimate. The County Engineer suspects the loss of soil that would result from the ditch construction and stabilization would be much less than the difference that can be attributed to the steepness of the two slopes. The applicant believes there is a greater chance for soil loss with the cleanwater channel around the construction site. "excessive stormwater runoff As with nearly all single family home construction, stormwater runoff from the site will be increased, though the addition will likely be negligible. The applicant has indicated that they are thinking of including a cistern on the property which will help bring the property closer to pre - development hydrology. "siltation" Please refer to "movement of soil and rock" section. "loss of aesthetic resource" The Open Space Plan identifies critical slopes in this area and shows this site as adjacent to Dudley Mountain, but does not make any recommendations that pertain to this site. Planning has reviewed the application and determined there would be no loss of aesthetic resource associated with the requested slope disturbance. "septic effluent" Albemarle County Current Development review will defer to the Virginia Health Department (VDOH) with regards to the construction of septic systems on critical slopes. VDOH does not object to the placement of the septic system on critical slopes. In fact, VDOH is prohibiting the construction of a septic system in the only area of the site where critical slopes are not present. Based on the above review, the applicant has satisfactorily addressed the technical criteria for the disturbance of critical slopes. Section 4.2.5(a)(2): This site does not drain into a waterway that is a public drinking water supply for Albemarle County. No portion of this site plan is located inside the 100 -year flood plain area according to FEMA Maps, dated 04 February 2005. Engineering review cannot conclusively agree with the applicant that all five "public health, safety, and welfare factors" are better served with the approval of the waiver. The County Engineer suspect that the construction of the building on the 28% slope as proposed will result in more soil loss than if the building was constructed in the southeast corner with a properly sized and lined diversion channel around the house. Admittedly, there is not a lot of evidence available to support either position. (For septic effluent, Engineering defers to VDOH, who has weighed in already.) 4 However, the County Engineer does think it is important to remember that total soil loss from a site is influenced not only by existing and proposed grades but also by total disturbed area and time of construction. Considering these factors, the current proposal is likely below the county averages and, therefore, may lose less soil than many other properties that do not require waivers for critical slope disturbance. This may be helpful to keep in mind when the agent and Planning Commission are evaluating whether this waiver should or should not be granted. PART II Current Development Planning Staffs review: Section 4.2.5(a)(3): The commission may grant a modification or waiver if it finds that the modification or waiver would not be detrimental to the public health, safety, or welfare, to the orderly development of the area, or to adjacent properties; would not be contrary to sound engineering practices; and at least one of the following: A. Strict application of the requirements of section 4.2 would not forward the purposes of this chapter or otherwise serve the public health, safety or welfare; Strict application of the requirements of section 4.2 would require the building site to be located out of critical slopes. This property contains a large number of critical slopes (over 59% of the property is critical slopes) and the only contiguous area large enough to accommodate a building site that is out of critical slopes is located in a natural drainage -way [Attachment C]. The existing building site was formerly the site of a mobile home (now removed) and a drainfield that was installed pre- ordinance, and is now abandoned. The Health Department has reviewed the request to build a new home on the property, and in the interest of public health has explicitly stated that the existing drainfield may NOT be used [Attachment H]. The Health Department, pursuant to Section 4.2.4, attempted to located an area outside of slopes 20% and greater for the new drainfield, but were not able to [Attachment G]. They have approved the drainfield location on critical slopes as proposed in this request [Attachment K]. Allowing disturbance of critical slopes facilitates the placement of new primary and reserve drainfields that meet the requirements of the Health Department, and therefore protects and furthers public health objectives. In addition to the drainfield issue, the applicant has stated that they wish to build their home out of the existing building site to reduce the possible flooding and health risks associated with placing a foundation in a drainage -way. They provided a certified letter from a licensed engineer supporting their claim that pursuant to public health, safety, and welfare objectives, the house should not be required to be built in the drainage -way [Attachment J]. County Engineering has reviewed the proposal and in their report [Attachment F] noted there are methods that could be employed to divert runoff around the house, should the critical slopes waiver not be approved. While there may be other methods to divert runoff away from the foundation, should the house be required to be built out of critical slopes, the health department will not allow the drainfield to be located anywhere but on critical slopes. Allowing disturbance of critical slopes for both the construction of a new drainfield and to locate the house out of a drainageway does further the public interest by allowing public health standards and objectives to be met. B. Alternatives proposed by the developer or subdivider would satisfy the intent and purposes of section 4.2 to at least an equivalent degree; The developer did propose an alternative that would satisfy the intent and purposes of section 4.2 to at least an equivalent degree. As noted above, the Health Department denied their inquiry into using the existing drainfield that is located out of the critical slopes, and, there are no other appropriate areas on the site that are not within critical slopes upon which to install a drainfield. C. Due to the property's unusual size, topography, shape, location or other unusual conditions, excluding the proprietary interest of the developer or subdivider, prohibiting the disturbance of critical slopes would effectively prohibit or unreasonably restrict the use of the property or would result in significant degradation of the property or adjacent properties; or As noted above, the property is over 59% critical slopes, and the only area that is large enough to accommodate a building site, and is out of critical slopes, would be denied by the Health Department. Prohibiting the disturbance of critical slopes to accommodate new drainfields would in essence render the property unusable for residential purposes. Erosion and sediment control regulations offer protection to adjacent properties. To ensure that erosion and sediment control measures are followed, and to minimize runoff and siltation during construction, an Agreement in Lieu of Plan is required with the building permit and there should be no detrimental impacts to the public health, safety, and welfare of adjacent properties. Approving the waiver would not be detrimental to the orderly development of the area and would not result in significant degradation of the property or adjacent properties. D. Granting the modification or waiver would serve a public purpose of greater import than would be served by strict application of the regulations sought to be modified or waived. This property is located within the County's Rural Area zoning. The Comprehensive Plan landuse recommendation is Rural Area 4 in Rural Areas, which promotes agricultural uses and rural residential when related to a bona fide agricultural/forestal use. The Comprehensive Plan states that the limited amount of residential development permitted in the rural areas should be located in a manner to minimize impact on rural resources and to minimize conflict with agricultural /forestal activities. Due to its topography and small size (2.0 acres), it would be very difficult to efficiently use this property for agricultural uses, and therefore to allow this property to be used for a single family dwelling would not conflict with the intent of the Rural Areas to preserve land for agriculture. The proposed conditions of this waiver would ensure that the property is only disturbed/cleared to the limits reviewed, and thus to the greatest extent possible while still allowing use of the property, the rural character of the property will be preserved. Granting the waiver, thus enabling the development of the lot for single family residential in conformance with Virginia Department of Health requirements, does not conflict with public policy objectives. SUMMARY AND RECOMMENDATION: Staff review has resulted in both favorable and unfavorable findings: Favorable factors: 1. Granting the waiver would allow the house to be located out of a concentrated drainage -way. While the County Engineer has identified a method to divert runoff around the house if it were located on the existing building site (out of critical slopes), granting the waiver would allow the house to be located out of the concentrated drainage -way altogether. 2. Granting the waiver would allow the new septic system to be permitted by the Health Department; Health Department will not permit existing drainfield to be used, and without an approved drainiield the property cannot be used for residential purposes. Allowing the existing platted lot to be used for a single - family residence furthers Comprehensive Plan objectives. 3. According to the County Engineer's review of the request, conformance with state Erosion and Sediment Control standards are required, and the disturbance associated with allowing the building site to be located on the proposed critical slopes would likely not result in any more soil loss than many other projects in the County that do not require critical slopes waivers. 6 Unfavorable factors: 1. According to the County Engineer's review of the application, total soil loss would likely be greater than if building site were located out of critical slopes. 2. According to the County Engineer, the construction of a diversion channel could direct drainage water around the house foundation if house must be located in the southeast corner of the site, out of critical slopes. A waiver to allow the drainfield to be located out of the building site, and on critical slopes would still be required. Staff opinion is that the favorable factors outweigh the negative factors and therefore staff recommends approval of this waiver with conditions: RECOMMENDED CONDITIONS: 1. Limits of disturbance shall be in general conformance with the exhibit provided by the applicant (exhibit dated August 16, 2010 (attached). 2. If, in the future, additional clearing for the reserve drainfield is required (location as shown on exhibit mentioned above) an amendment to this waiver is not needed. ATTACHMENTS: A. Request for Wavier (applicant justification) (4 pages) B. Vicinity maps (1 page) C. Topographic survey of property, dated 7 -27 -09 (1 page) D. Disturbance Exhibit, dated 8 -16 -10 (1 page) E. Applicant's response letter to Engineering comments, dated 8 -16 -10 (2 pages) F. Revised Engineering review email and memorandum, dated 8 -20 -10 (4 pages) G. Health Department/Zoning Administrator email re: Sec 4.2.4, dated 8 -10 -10 (1 page) H. Health Department email explaining denial of existing building site, dated 8 -3 -10 (1 page) I. Health Department denial of existing building site, email dated 9 -1 -09 (1 page) J. Certified letter from licensed engineer about house in drainage -way, dated 6 -26 -10 (1 page) K. Health Department Approval of proposed drainfield location, dated 6 -29 -10 (2 pages)