Frequently Asked Questions

development review - frequently asked questions
Last updated March 2021

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 system we operate.

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.

Click here to learn more about the District’s development review process.

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 within the drainage district’s boundaries 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” or “the Columbia Corridor Drainage 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?

The Districts review development applications with a tiered review system that allows for simple applications to be reviewed quickly and more complex reviews to be conducted more consistently.  Complex reviews are subject to a service charge. Learn more about the different types of fees here.

Why was the service charge established?

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.

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.

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).

General triggers for escalating to Tier 2 include:

  • A District owns or maintains infrastructure on the property
  • A District holds an easement on the property
  • The proposed development potentially impacts MCDD’s staff ability to access or maintain the internal drainage system
  • The proposed development potentially impacts MCDD’s staff ability to respond to a flood event
  • The proposed development is on or adjacent to a federally authorized flood control levee

General triggers for escalating to Tier 3 include:

  • The development proposal requires complex easement negotiations or modifications
  • The development proposal requires evaluation and additional engineering analysis of impacts to the interior drainage system, including potential mitigation measures
  • The development proposal changes, or significant additional issues are discovered during the development review process
  • A Section 408 Review by the USACE or a levee review to permit an alteration of a levee constructed by a local interest (non-federal) is required
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 or engineering analyses are needed. 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. Starting February 1, 2021, all Tier 2 reviews are charged a $710 Intake Fee which includes the intake processing to cover staff time and an additional Tier 2 Fee of $1,510.

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 tier 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?
  • Tier 1 = No charge; cost covered as part of the Districts’ operating budget
  • Tier 2 = $710 Intake Fee + $1510 Tier 2 Fee
  • Tier 3 = Tier 3 Fee that is invoiced monthly for total hours required for review
How do I submit payment to my corresponding District?

You can submit payment two ways:

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 districts’ 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.