The draft plan proposes to incorporate stormwater management into the landscape of River Terrace. Different tools are proposed for different areas depending on the characteristics of each location. Several Low Impact Development Approaches (LIDAs) are included. LIDA works with nature to manage stormwater as close to its source as possible.

We heard concerns, questions, and comments about the proposed plan in each stakeholder meeting held on December 18, 2013. These include:


  • What are the benefits ofLIDA, if not for infiltration?
    • Flow through LIDA facilities are primarily needed for water quality
    • LIDA facilities for quantity management will be needed under the new regulations; not just in peak storm.
    • Why are there different approaches for different portions of River Terrace?
      • Because the topography, soils, and natural drainage ways vary throughout River Terrace, different approaches have been applied in different areas.
      • There are maintenance costs for lot by lot LIDA, and enforcement issues.
      • Tigard has an opportunity to set a standard for LIDA. Return the hydrograph in this area to pre-development standards.


  • Regional facilities are expensive and currently lacking a funding source.
  • Facilities designed to serve multiple properties could limit development of smaller projects and distant sites.
  • LIDA treatments are expensive, if needed on every site.
  • LIDA facilities require regular maintenance to function properly, and maintenance can be challenging for homeowners and city public works crews.
  • Sometimes stormwater that runs through a LIDA facility is “double treated.”


  • LIDA can be expensive, for developers and for the city.
  • The vision for stormwater management to be incorporated into the landscape of River Terrace was an important aspect for some SWG committee members.
  • There are existing stormwater problems on Bull Mountain that should be avoided in River Terrace.
  • The maps should be updated to make it more clear where and when LIDA will be used or required.

Discussions on stormwater will continue in January at an Implementation Subcommittee meeting and online. Please add any questions or comments below.