Development Reviews

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 increase the risk of floodingand complies with local, state, and federal regulations.

Our tiered review structure aims to provide developers with as much information and predictability as possible.  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 if more information is needed on potential impacts or mitigation is required.

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.

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Last updated August 1, 2018

What types of projects require a review?

Any project that requires digging, paving, placing gravel or concrete, grading, or might otherwise impact the levees or drainage on a property within the drainage districts is subject to review by the Multnomah County Drainage District #1 (MCDD).  MCDD staff also conduct these reviews on behalf of three other special districts dealing with flood risk: Peninsula Drainage District #1 (PEN1), Peninsula Drainage District #2 (PEN2), and the Sandy Drainage Improvement Company (SDIC).  MCDD, PEN1, PEN2, and SDIC are collectively referred to as “the Districts”.

What benefits does the Districts’ review provide?

The Districts review development applications for projects within the Districts’ boundaries to make sure development does not increase flood risk and complies with regulations.

What has been updated with the Districts’ development review process?

As of May, 2018, the Districts began reviewing development applications with a new tiered review system. The new review system helps the Districts to review simple applications more quickly and provide a transparent and consistent process for complex reviews. Complex reviews are now subject to a service charge.

Why was the service charge established?

The Districts are reviewing more applications than ever before.  Due to new regulations, these reviews are more extensive and require more time. The service charge allows the Districts to be more responsive to development review requests by ensuring adequate staffing is available to the Districts’ core services and application reviews. The service charge also allows the Districts to work with consultants, when needed.

When will the service be implemented?

The service charge took effect on May 17, 2018 and is now being implemented.

Will more time be required for the new tiered review process?

No. Our goal remains to fit within the local jurisdiction’s permitting timelines.

What is the difference between the three tiers of review?

The level of review (Tier 1, 2 or 3) is based on the complexity of the review required, which accounts for the project’s proximity and potential impact to flood protection systems (including levees).

How do I know what level of review my project will require?

The Districts’ review process is linear – all projects start at the simplest level of review (Tier 1) and move to more thorough review if more information is needed on potential impacts or mitigation is required. You will be notified by District staff if your project requires an additional tier of review.

The next level of review (Tier 2) is completed for projects that may affect levees or interior drainage systems within the Districts.

The highest level of review (Tier 3) is done on applications that require a lot of time or expense for the Districts, such as those with community interest and those requiring legal counsel or outside contractor expertise. This also includes projects that trigger U.S. Army Corps of Engineers (USACE) requirements for alteration of federal levees.

In all cases, the Districts provide comments and conditions for approval to the agency processing your permit application. Final development permits are issued by the agency processing your application.

How much is the service charge?

If a review is subject to a service charge, the charge will be invoiced monthly until the review is completed, up to a maximum amount. The service charge schedule is:

  • Tier 1 = No charge; cost covered as part of the Districts’ operating budget
  • Tier 2 = $550 one-time base fee + monthly invoice for additional costs incurred (maximum $2,500 total, excluding the base fee)
  • Tier 3 = Monthly invoice for total hours required for the review

How do I submit payment to my corresponding District?

You can submit payment two ways:

  • Credit card: Pay online with a credit or debit card via Point and Pay. You can find the link to each district under “Development Review,” in the navigation page of the District’s website:
  • Check: Make checks payable to the corresponding District for your review and mail to the Multnomah County Drainage District, 1880 NE Elrod Drive, Portland, OR 97211

Does everyone in Multnomah County require a development review by the Districts?

No, only projects that fall within the Districts’ service area are subject to this review. To see a map of the district boundaries, visit

Can I get an early estimate of how much my project review might cost?

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.

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