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Drainage Plans & Reports

Drainage plans provide information on managing stormwater. They are an integral part of both large watershed-level planning studies as well as for individual developments by detailing the storm servicing requirements. Drainage plans can be part of a drainage report, a stand alone figure or a combination of both.

Drainage plans provide information on many of the following:

  • Overall catchment area
  • Drainage sub catchments
  • Catchment characteristics
  • Slope
  • Land Use
  • Soils
  • Minor flows (5 year design storm runoff)
  • Major flows (100 year design storm runoff)
  • Existing storm system infrastructure and capacity
  • Proposed storm system infrastructure and capacity

Drainage reports address the condition of the existing drainage system. They list recommendations on a specific local drainage issue or can address large areas providing information on general catchment opportunities and constraints. They recommend solutions for specific issues or addressing larger concerns and are used to plan for future development.

Drainage reports present the results of investigations into issues that affect the drainage system and its various components. The reports compile information on many related factors providing conclusions and recommendations to effectively manage the drainage system.

Drainage reports, depending on the reports objectives, can provide information on one or more of the following:

  • Overall catchment area
  • Drainage sub catchment areas
  • Catchment characteristics (such as land use, rainfall patterns, groundwater, soils, slopes, slope stability)
  • Contaminates sites
  • Environmentally sensitive areas
  • Terrestrial Wildlife issues
  • Watercourses
  • Water quality issues
  • Erosion concerns
  • Minor flows (5 year design storm runoff)
  • Major flows (100 year design storm runoff)
  • Existing storm system infrastructure and capacity
  • Proposed storm system infrastructure and capacity

Drainage reports can include issues that extend beyond just storm water as the changes in one area affects everything else. The integration of storm water management planning requires consideration of many factors.

Documents where you may find drainage plans &/or reports include:

  • Integrated Storm Water Management Plans (ISMP)
  • Master Drainage Plans (MDP)
  • Functional Feasibility Plans  (FFP)
  • Area Servicing studies
  • Neighbourhood Concept Plans (NCP)
  • Development Application plans as Storm water Control Plans
  • Preliminary Design assessments
  • Reports commissioned for specific infrastructure management issues.

Most Surrey drainage plans and reports are available from the City’s GIS department by applying online at  GIS document services.  A list of available reports is available at Drainage Report List.