Review Process


MCDD reduces flood risk by maintaining our levee system, managing drainage, and responding to emergencies. As part of these responsibilities, MCDD reviews development applications for projects within the Districts’ boundaries. These reviews ensure new development does not detrimentally impact the management or maintenance of the federally authorized levee or interior drainage systems we operate.

Our tiered review structure aims to provide developers with an upfront overview of the review process, based on the level of review required for a given development.  The level of review – Tier 1, 2, or 3 – is based on the project’s proximity and potential impact to flood protection systems and the complexity of the review required. All projects start at the simplest level of review and move to more thorough review tiers if more information or engineering analyses are needed.

The Districts can set up a free pre-application meeting to help identify potential mitigation needs early and explain submittal requirements for complex projects. Contact Flood Control Director Bill Owen at 503.281.5675 ext. 321 or to set up a free pre-application meeting.

What to Expect

The City managing your development application sends review requests to MCDD to identify any flood risk or necessary mitigation measures. In most cases, MCDD directly provides the City comments that are incorporated into the City’s final permits and no further contact or payment is required. For projects where flood risk or necessary mitigation measures are identified, MCDD will conduct a higher level of review. You will be notified if this is the case.

Please contact the appropriate city department for questions related to development in their jurisdiction:

Links & Documents
Development Review 3-tier process

Development Review Criteria

The Districts review development and construction projects proposed within the boundaries of the Multnomah County Drainage District, Peninsula Drainage Districts 1 and 2, and the Sandy Drainage Improvement Company. The city managing development applications requests development reviews for projects within a district’s boundaries. If an initial review finds a potential for flood risk or need for mitigation, the Districts conduct a deeper review. Development proposed on or near a levee in Zones A, B and C (see illustration below) are additionally reviewed by the US Army Corps of Engineers (USACE).

Development reviews look primarily at three categories:
Access to operations and maintenance

New development must allow access for the Districts' operations and maintenance of levees and interior drainage systems.

Hydraulic Capacity

The Districts manage a series of complex systems that move water throughout the managed floodplain. Any changes that would reduce capacity or introduce new flows need a detailed review.

Infrastructure Impacts

New development, such as utility installations, can often pass near or even modify assets the Districts maintain. These projects are reviewed for potential impacts to safety, accessibility, and maintainability.

Levee Review Standards

The District follows standards defined by the US Army Corps of Engineers (USACE). To learn more, the Districts can set up a free pre-application meeting to help identify potential mitigation needs and explain submittal requirements. To set-up a pre-application meeting, or for specific questions relating to development near the levees or waterways, contact us at