DCGIS.MS4StormSewershedDissolvePly

Metadata also available as

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: District Department of the Environment
Publication_Date: 20111105
Title: DCGIS.MS4StormSewershedDissolvePly
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage:
Server=10.1.11.144; Service=5151; User=dcgis; Version=SDE.DEFAULT
Larger_Work_Citation:
Citation_Information:
Originator: DC GIS
Title: DC Geographic Information System
Geospatial_Data_Presentation_Form: vector digital data
Description:
Abstract:
District MS4 Sewershed drainage areas. The dataset contains locations and attributes of the drainage areas of MS4 outfalls created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies.
A database provided by WASA identified outfalls, drainage structures, and MS4 outfall locations.
All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters.
METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.
Purpose:
This data is a requirement of the District's MS4 Permit. It is used for stormwater management in the District.
Supplemental_Information:
MS4 Sewershed Facts and Limitations:
The new MS4 Sewershed layer is a new iteration of existing MS4 sewersheds. Upon reviewing WASA and LimnoTech sewersheds, it was found that both layers depict single drainage systems per sewershed but the actual drainage area of each storm drainage system was not adequately depicted. This version of the MS4 sewershed is also based on contours but 2' contours were used and were available whereas a 1 meter contour was available before.
Other data layers used include both existing sewersheds, breaklines, elevation points, road edge, sidewalks, parking lots, alleys, WASA CSO, Sanitary, and MS4 sewer gravity mains, catch basins, manholes, NPDES outfalls, sewer outfalls, MS4 outfalls (04-06 GPS survey), and other relevant DC planimetric layers. Counter maps and plans were georeferenced and used as verification of existing sewer GIS data. Google Street View was used for field verification desktop side. Some examples include elevation changes, roof drainage direction and outlets of down spouts if visible.
The delineations depict the "headwaters" of each storm sewer system and include all surface areas that will drain to strormwater catch structures. Areas where storm water is transported by pipe network are also depicted. This results in polygons with thin elongated areas that appear to traverse over other sewershed polygons and or end up at an outfall. The areas where these thin elongated part(s) of a sewershed traversing through other sewershed(s) add to the area of its sewershed and also take away area from the sewershed that was traversed through.
Level of Accuracy:
This sewershed layer was created with reliance on the new 2 foot topographic contours. Adjustments to the delineations were done where man-made structures exist such as curb, buildings, walls, etc. that can divert the flow of surface water. Sometimes adjustments were also necessary as lot gradings are usually sloped away from buildings even when contours don't show it. Therefore certain locations the delineation may not follow contour exactly. This was verified by use of Google Street View to verify actual land surface and grading. It can be concluded that the accuracy of this data is much better than the 2 existing sewershed because of the availability and use of road edge, buildings, new technology (Google Street View) and updated data such as 2' contours.
Assumptions and Criteria:
1. Storm sewer GIS data are used to determine structure location. If structure location can be identified by ortho photo, the location visible in the ortho photo will be used if verifiable with Google Street View. 2. Delineations start at the outfall point determined by above step. 3. Delineated area depict pipe (water transport) from the outfall back up to the first storm inlet structure (area of the outfall pipe minimized but still able to show outfall pipe location and outfall) 4. Polygon boundaries of delineated areas are digitized perpendicular to contour lines to depict possible water flow direction. This is seen on roads where water from the centerline flows toward the catch basin due to road banking. 5. Solid walls, building foundations, or similar structures such as curbs and sold permanent barriers will divert the flow of water. (Verified by Google Street View) 6. Building roof (design) can alter flow of water with consideration of where downspouts from gutters outlets and direction they point. 7. Any pipe that daylights (outfall) is considered a storm system no matter whether it's 1 pipe or a pipe network 8. Areas that don't have GIS for storm infrastructure, contour, roads, buildings, orthophoto and Street View are used to estimate most likely storm drainage system routing to determine sewershed.
Data needing field verification:
2000 series outfall ids are ids given to outfalls that exist in WASA's outfall database or outfalls that was estimated to be existing. The WASA outfalls that did not have a location matched GPS outfall point were most likely to have been missed during the 2004-2006 GPS surveys. Once all 2000 series outfalls have been verified to either exist or not and have some more data attributes collected for them, then they can be determined if they meet the MS4 criteria and definition of being a MS4 outfall. Basically all drainage pipes that daylights are captured and assumed to be MS4 and have an outfall.
Impervious layer (MS4 Sewersheds Impervious):
This layer was created by overlaying the MS4 Sewershed over the Impervious Surface from DCGIS Central. The resulting modified impervious layer would also display the "perceived overlaps" because of the method the sewersheds were delineated. Those areas had to be manually reassigned to the correct sewershed. In the case of impervious surfaces, the location of the outfall was assumed to be non essential. Therefore, areas where another sewershed's outfall pipe crossed over can be reassigned back to the overlapped sewershed.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20111105
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -77.114322
East_Bounding_Coordinate: -76.909018
North_Bounding_Coordinate: 38.994517
South_Bounding_Coordinate: 38.804430
Data_Set_G-Polygon:
Data_Set_G-Polygon_Outer_G-Ring:
G-Ring_Point:
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: Environment
Theme_Keyword: storm
Theme_Keyword: sewershed
Theme_Keyword: rain
Theme_Keyword: drainage area
Place:
Place_Keyword: District of Columbia
Place_Keyword: DC
Place_Keyword: DC GIS
Place_Keyword: DCGIS
Use_Constraints:
For data terms and conditions, go to <http://dc.gov/page/terms-and-conditions-use-district-data>
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Julia Evans
Contact_Organization: DDOE
Contact_Position: Environmental Engineer
Contact_Address:
Address_Type: mailing address
Address: 1200 1st Street NE 5th Floor
City: Washington
State_or_Province: DC
Postal_Code: 20002
Country: USA
Contact_Facsimile_Telephone:
<The facsimile telephone number, including area code, of the Contact Person.>
Contact_Electronic_Mail_Address: <The Internet mail address of the Contact Person.>
Hours_of_Service: <The hours of service of the Contact Person.>
Data_Set_Credit: District Department of the Environment
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.4000

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Attributes wer derived with regard to field surveyed MS4 outfall locations in the MS4 permit, data from existing available GIS data and staff research of receiving waters.
Logical_Consistency_Report: In process of validation of 2000 series outfalls
Completeness_Report: Validated by source and/or responsible agency
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Data acuracy is dependent upon contour, structures, storm drainage structures, and actual features on the land surface.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report: N/A
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: District Department of the Environment
Publication_Date: 2011
Title: MS4 Storm Sewershed
Online_Linkage: <http://ddoe.dc.gov>
Type_of_Source_Media: audiocassette
Source_Citation_Abbreviation: MS4 Storm Sewershed
Source_Contribution: location and attribution
Process_Step:
Process_Description:
Boundaries were derived from contour, taking in to account any features that may impede or alter the flow of water, such as road edge, walls, buildings, and catch basins. Google street view was used in verifying locations of catch basins, roof drainage and downspout locations where applicable, and contour of land as actual field visits were not possible.
Process_Date: 20111105
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: District Department of the Environment
Contact_Address:
Address_Type: mailing and physical address
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: C:\temp\MS4StormSewerShedPly.xml
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: C:\GISHOME\Stormshed_metadata.xml
Process_Date: 20110224
Process_Time: 12104100
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Dataset copied.
Source_Used_Citation_Abbreviation: \\DDOE-G7C8HF1\C\GISHOME\MS4SewershedEdit.mdb
Process_Date: 20110322
Process_Time: 12240000
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Dataset copied.
Source_Used_Citation_Abbreviation: \\DDOE-G7C8HF1\C\GISHOME\Pestcides\Pesticides_data.mdb
Process_Date: 20110324
Process_Time: 14464500
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Dataset copied.
Source_Used_Citation_Abbreviation: \\DDOE-G7C8HF1\C\GISHOME\updates_03312011.mdb
Process_Date: 20110401
Process_Time: 12343000
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Dataset copied.
Source_Used_Citation_Abbreviation:
\\dcgisshare.dcgis.in.dc.gov\public\DDOE_SWMD\updates_03232011.mdb
Process_Date: 20110401
Process_Time: 14074500
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor
Process_Step:
Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: C:\temp\MS4StormSewershedDissolvePly.xml
Process_Date: 20110405
Process_Time: 17030400
Process_Contact:
Contact_Information:
Contact_Address:
Address: 200 I Street SE, 5th Floor

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 1

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 1900
Lambert_Conformal_Conic:
Standard_Parallel: 38.300000
Standard_Parallel: 39.450000
Longitude_of_Central_Meridian: -77.000000
Latitude_of_Projection_Origin: 37.666667
False_Easting: 400000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000063
Ordinate_Resolution: 0.000063
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Resolution: 1.000000
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: DCGIS.MS4StormSewershedDissolvePly
Attribute:
Attribute_Label: OBJECTID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: SHAPE
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: SHAPE.LEN

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: DC Office of the Chief Technology Officer
Contact_Person: GIS Data Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 200 I Street SE, 5th Floor
City: Washington
State_or_Province: DC
Postal_Code: 20001
Country: USA
Contact_Facsimile_Telephone: (202) 727-5660
Contact_Electronic_Mail_Address: [email protected]
Hours_of_Service: 8:30 am - 5:30 pm
Resource_Description: Downloadable Data
Distribution_Liability:
For data terms and conditions, go to <http://dc.gov/page/terms-and-conditions-use-district-data>
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 0.040
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Ordering_Instructions: All data is available at <http://opendata.dc.gov>

Metadata_Reference_Information:
Metadata_Date: 20110405
Metadata_Review_Date: <publication date - format dd/mm/yyyy>
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: D.C. Office of the Chief Technology Officer
Contact_Person: GIS Data Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: 200 I Street SE, 5th Floor
City: Washington
State_or_Province: DC
Postal_Code: 20001
Country: USA
Contact_Voice_Telephone:
REQUIRED: The telephone number by which individuals can speak to the organization or individual.
Contact_Facsimile_Telephone: (202) 727-5660
Contact_Electronic_Mail_Address: [email protected]
Hours_of_Service: 8:30 am - 5 pm
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.9.12 on Thu Jun 25 14:49:15 2015