Manholes
Keywords: Manhole, Stormwater, Asset, Asset Management
Published: 2008
Richmond GIS Layer Inventory
Contact Richmond GIS
 
Description
  Abstract: Represents a Manhole. A manhole, or maintenance hole, is a tube which connects underground utilities to the surface. The tube is large enough to accommodate the body of a utility worker, and is covered with a top that is flush to the ground, and called a manhole cover. Manholes are frequently found connected to water and sewer systems. A manhole is a type of "junction" in GIS. A junction is a point location along the stormwater system. These are the points that were collected and attributed by the consultant to assist in "connecting-the-dots." Junctions include features like manholes, curbside drop inlets, grate inlets, culvert boxes, etc.
  Purpose: Manholes are used to access underground stormwater infrastrucure. Manholes are used in a GIS-based Asset Management System (AMS), which supports work coordination, asset replacement/planning, asset inventorying, mapping, and over-all management of the stormwater system. Manholes are also capable of participating in a geodatabase network for modeling water flows.
  Supplemental Information: Stormwater features were combined with other natural hydrological surface water features (streams) in this dataset, in order to eventually support the modeling and tracing of water flow through both the man-made infrastructure and natural water features. Currently, the stormwater features have topological relationships that allow for building a network that can be used for tracing upstream/downstream flows. Stormwater system and natural streams, however, are currently disconnected. Stream data could be improved and included to participate in stormwater's network, which would allow tracing all the way to/from the James River to/from source points of the stormwater system. Notes on stormwater system data capture (2003-2005): Original field mapping/inventorying of stormwater features was driven by the Department of Public Works' (DPW) stormwater engineer to 1) meet Virginia Pollutant Discharge Elimination System (VPDES) General Permit Number VAR040, and 2) to prepare for the use of these features in an Asset Management System. According to the VPDES mandate, all outfalls 36 inch diameter and greater, or 12 inch diameter and greater in industrial areas, were identified and tabulated. Subsequently, with the support of DPW's stormwater engineer, the GIS Team then consulted to have GPS field data collection of these VPDES outfalls and all of the upstream infrastructure feeding them. Following the initial mapping for VPDES, the GIS Team continued to contract for additional GPS-based field data collection of the south-side annex area to fill in any of the remaining gaps. This initial GPS field data collection was performed in FY02-03 and FY03-04. Some of the outfall systems defined by VPDES were digitized from DPW's existing hardcopy maps, although most had to be field collected. Manholes were one one the feature types that the DPW stormwater engineer identified for inventorying, and manholes were available for interpretation from the existing mapping. In 2004, the stormwater system maps housed in DPW were digitized by a GIS Technician. These maps covered the older parts of the City (pre-annex), which were primarily maps of north-side and not part of the combined sewer system, and included areas on the south-side that were in the Jefferson Davis Hwy corridor. (Note: please see hydr_SystemBoundary feature class for description and coverage of mapped areas.) The Stormwater system conversion effort stopped in 2004, leaving approximately 40% of the City's southside stormwater system unmapped. It was not until 2008, that the Department of Public Utilities (DPU) consulted with their gas/water/sewer/street light data conversion vendor to complete the mapping of the stormwater system. Notes on stormwater system data capture (2008): The City possessed annex stormwater system maps, produced by J.K. Timmons and Associates in 1983, as a supplement and update to The Comprehensive Drainage Study of the 1970 Annexation Area of Richmond. These maps were never used in the original effort, because they were recognized as incomplete or inaccurate. DPU's consultant digitized stormwater infrastructure for the south-side annex area from these maps, in addition to conducting GPS field inventorying for the remaining 40% of unmapped areas, which included the capture of additional Manholes. Important Note: The hydrology dataset will require further evaluation & re-organization as Stormwater comes on-line in DPU and when the City needs to support stream network modeling; additional attribution of streams will be needed, i.e. perennial -vs- non perennial indicators. While the original data collection activities did not result in the population of the EditBy and EditDate attribute fields, feature level metadata is now enabled on these assets with the use of these fields. Every feature in the GIS layers can be tracked according to who edited it, and when it was last edited. Internal documentation and background about the stormwater data collection project (2002-2005): Q:\Infrastructure\Geodatabase\Datasets\Hydrology\StormWater\StormwaterProject.doc
 
Contact
  Custodian: Eddie Childers
  Department: Public Utilities
  Position: GIS Manager
  Address: 400 Jeff Davis Hwy
  City: Richmond
  State: Virginia
  Zip Code: 232224
  Email: Eddie.Childers@richmondgov.com
 
Time Period of Content
  Beginning Date: 200301
  Ending Date: 200810
 
Status
  Progress: Complete
  Update Frequency: As needed
 
Spatial Domain
  West Coordinate: -77.595198
  East Coordinate: -77.390697
  North Coordinate: 37.597646
  South Coordinate: 37.459723
 
Spatial Data Information
  Data Type: vector digital data
  Data Format: SDE Feature Class
  Data Projection: Lambert Conformal Conic
 
Access and Usage Information
  Access Constraints: none
  Use Constraints: All GIS layers and datasets are owned by the City of Richmond and can not be modified, re-distributed, and/or re-sold without a sub-licensing agreement. All guarantees of validity expire once a dataset leaves the City of Richmond firewall or physical premises. Acknowledgement of the City of Richmond GIS would be appreciated in products derived from these data.
 
Entity and Attribute Information
  Entity Name: vector.ric.hydr_Manhole
  Entity Type: Feature Class
  Entity Count: 2064