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Integrated Stormwater Management Plan (ISMP)


In BC, the term Integrated Stormwater Management Planning (ISMP) has gained widespread acceptance by local governments and environmental agencies to describe a comprehensive, ecosystem-based approach to rainwater management.

The purpose of an ISMP is to provide direction for future development plans and identify infrastructure needs. The goal is to balance:

  • Land use planning
  • Stormwater engineering
  • Flood and erosion protection
  • Environmental protection

In the past, stormwater management planning had a primary function to identify the infrastructure needed to service increased development. The impacts of development were given little consideration.

Today’s stormwater management planning has evolved significantly to become a comprehensive approach to also include the preservation and utilization of resources within a watershed. An ISMP is intended to balance the land use needs with the natural values and functions of the watershed.

Traditional stormwater management planning

  • Drainage Systems
  • Reacting to Problems
  • Engineer-Driven
  • Protect Property
  • Pipe and Convey
  • Unilateral Decisions
  • Local Government Ownership
  • Extreme Storm Focus
  • Peak Flow Thinking

Integrated stormwater management planning

  • Ecosystems
  • Preventing Problems
  • Interdisciplinary Team-Driven
  • Protect Property & Habitat
  • Mimic Natural Processes
  • Consensus-Based Decisions
  • Partnerships with Others
  • Rainwater Integrated with Land Use
  • Volume-Based Thinking

The Ministry has developed Stormwater Planning Guidebook - Chapter 9, a Guidebook for developing and implementing ISMPs.

Surrey is committed to having an ISMP in place for each watershed across the city. See our progress on the Sustainability Dashboard. You can also view information for the ISMPs that are complete, active or pending.


urban detention pond

Active ISMPs

View updated info on Surrey's active ISMP areas

detention pond

Pending ISMPs

Read updates on the ISMP areas that are still pending the start of a study of the area.

ISMP example of bioswale

Completed ISMPs

Read info on all the ISMP studies that are complete in Surrey.

Related Content

Latimer ISMP

Learn about the Latimer ISMP process and how you can be involved.

Upper Serpentine ISMP

Help protect the Upper Serpentine watershed by contributing your views on the ISMP process underway.

Water Pollution

Contact Surrey if you see your local creek water looking murky or a strange colour - it may be water pollution.