Type File Geodatabase Feature Class
The Mountainside Overlay District is a zoning overlay district (see Section 5.04 of the Loudoun County Zoning Ordinance) and regulates development on the mountainsides of the County. Mountainside data should be used for general planning purposes only and is not intended for use in delineating specific use or suitability of soils for a particular site. Areas prone to debris flow (slippage) may not be accurately delineated. The Department of Building and Development is responsible for final clearance and interpretation on zoning/building permits and land development applications for the Mountainside Overlay District. Please contact the Department of Building and Development to determine a Preliminary Soil Review has occurred on a parcel, which may have updated the mountainside information.
The MOD is a zoning overlay district administered by the Planning and Zoning Department, in conjunction with the Department of Building and Development, which was approved on December 13, 2023. Mountainside classifications are based upon the following criteria: critical elevation, soils, slope, and forest values. Critical elevation areas are determined from the County's digital topography, soil and slope values are based upon data from the County's soil layer, and forested areas are based upon the digital forest data.
As a result of the adoption of the new Loudoun County Zoning Ordinance on December 13, 2023, two new feature protections were added to the Overlay District, Spring and Ridge Feature Protection. They are subject to the Uses and Development Standards of Section 5.04.
March 9, 2020: MTNSIDE_POLY Features were updated by removing features where MT_SDE_VAL = 0, since they do not meet the Mountainside criteria. Mountainside value requires a value greater than or equal to 9.
The Mountainside Development Overlay District consists of three categories (identified in the field MT_SDE_VAL):
Somewhat Sensative = 9
Sensitive 10 to 13
Highly Sensitive >= 14
Please contact the Department of Building and Development to determine a Preliminary Soil Review has occurred on a parcel, which may have updated the mountainside information.
There are no credits for this item.
These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.
| West | -77.962730 | East | -77.533151 |
| North | 39.326040 | South | 38.940825 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
8:00-5:00 EST, M-F
These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.
Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user.
Data was extracted from pctbase.topo in 1999 and edited to form polygons and coded as above or below the critical elevation. Polygon topographic data was unioned with polygon data extracted from environment.soils and environment.forest in 1999. The elev_val, forest_val, and soil_val items were populated with appropriate values from lookup tables and were then summed to determine the mountainside score (mside_val).
This data set was part of a batch process that converted legacy data from ArcInfo coverage in Librarian to a single-tiled ArcInfo coverage in preparation for a final conversion to ArcSDE Geodatabase Feature Classes. Data were extracted from Librarian using the EXTRACT TOPOLOGICAL command.
Multi-tiled data sets were extracted into multiple coverages and then combined based on the feature type(s). Layers with both polygon and arc feature classes were processed with the Arc commands MAPJOIN and DISSOLVE. Arc feature classes alone were processed with the Arc commands, APPEND and DISSOLVE. Layers with both arc and point feature classes and point feature classes alone were processed with the Arc command, APPEND. When used, the arc command, DISSOLVE, was given with the <#all> option.
All coverages were then reprojected to HARN83 using the following .prj file specifications:
INPUT
PROJECTION STATEPLANE
UNITS FEET
ZONE 5551
DATUM NAD27 NADCON
PARAMETERS
OUTPUT
PROJECTION STATEPLANE
UNITS FEET
FIPSZONE 4501
DATUM HPGN NADCON
PARAMETERS END
The dataset was then converted to a feature class in a geodatabase in ArcSDE.As a result of the adoption of the new Loudoun County Zoning Ordinance on December 13, 2023, two new feature protections were added to the Overlay District, Spring and Ridge Feature Protection. They are subject to the Uses and Development Standards of Section 5.04.
overlay of elevation, soils and forest established MDOD
Monday - Friday, 8:00-4:30 EST, M-F
Size limit: 4.5 GB. Visit our website at: http://www.loudoun.gov/omagi, click on "Loudoun County Mapping Documents & Order Forms." The "Forms" directory will lead you to custom & standard (countywide) data order forms. Hardcopy maps may also be available; please contact the Mapping Office Public Information Counter for more information regarding all data requests.
Polygon Feature Class
ESRI
Critical elevation component value. Identifies if area is above or below.
Loudoun County
Forest component value. Identifies if area is forested or not.
Loudoun County
Soil component value of area based on groundwater recharge, slippage, slope, and whether it is a mountain soil. (see the Mountainside Development Overlay District Soils Worksheet for sub-totals of specific soil mapping units).
Loudoun County
Sum of MT_ELEV_VAL, MT_FOREST_VAL, and MT_SOIL_VAL, which is the overall sensitivity of the moutntainside area.
Loudoun County
Source that created or edited feature class
Loudoun County
Feature creation or modification date
Loudoun County
User generated text
Not for public distribution. Internal User ID of editor creating or modifying a feature.
Loudoun County
Feature geometry.
ESRI
Coordinates defining the features.
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
Length of feature in internal units.
Esri
Positive real numbers that are automatically generated.
Area of feature in internal units squared.
Esri
Positive real numbers that are automatically generated.
MT_ELEV_VAL: Value that identifies if area is above or below critical elevation component value. Critical elevation for the Catoctin Ridge is 550 feet, critical elevation for Short Hill and the Blue Ridge is 700 feet.
Value Definition 0 Below critical elevation 3 Above critical elevation
MT_FOREST_VAL: Value that identifies if area is forested or not.
Value Defination 0 Not forested 2 Forested
MT_MSIDE_VAL: Sum of MT_ELEV_VAL, MT_FOREST_VAL, and MT_SOIL_VAL, which is the overall sensitivity of the mountainside area. Mountainside consists of all polygons with scores of 9 or above.
Value Sensitivity 0 Non-mountainside 9 Moderately Sensitive 10 Sensitive 11 Sensitive 12 Sensitive 13 Sensitive 14 Highly Sensitive 15 Highly Sensitive 16 Highly Sensitive 17 Highly Sensitive 18 Highly Sensitive 19 Highly Sensitive 21 Highly Sensitive 23 Highly Sensitive
MT_UPD_SOURCE: Source that created or edited feature class
Source Definition 0 Unknown 1 Legacy 2 County 3 Contract
Monday - Friday 8:00 - 4:30 EST
This metadata reflects the source Geodatabase format and specific elements may not apply if your data is exported to SHP, DXF, or .e00 products. User must be aware that changes to data schema occur during data export that may not be reflected in this metadata, which represents Loudoun County's corporate geodatabase. Acknowledgement of Loudoun County would be appreciated in the use of this metadata.