MULTNOMAH COUNTY DRAINAGE DISTRICT NO. 1Multnomah County Drainage District No. 1 is located in Multnomah County, along the south bank of the Columbia River between river miles 108.2 and 119.0, approximately 10 -15 miles east of the city center of Portland. The drainage district includes 8,832 acres, of which 465 acres are lakes, and sloughs, Portland International Airport, Blue Lake Park, 3 golf courses, industrial and commercial enterprises, agriculture and suburban development. Land elevation ranges from 12’ to 25’ NGVD. The district area averages about 1 mile in width with NE Columbia Blvd and NE Sandy Blvd. paralleling the south boundary. The eastern boundary adjoins Sandy Drainage Improvement Company by a cross levee paralleling NE 223rd Ave. while on the western side Peninsula Slough cross levee located at NE 18th.
CONSTRUCTION HISTORY 1919 – 1921, Initial construction of 13.3-mile levee began. In addition, to the levee a 60,000 gpm pumping plant located at NE 18th, 5 pumping plants in the interior and 5 tide boxes were constructed for flood control.
1936, a pile dike was constructed opposite Northeast 33rd Drive.
1936 – 1939, local interests placed about 900 linear feet of revetment.
1939, a series of 939 pile dikes were constructed near the upstream end of the district at the head of McGuire Island and three additional pile dikes were constructed upstream as navigational aids.
1939 – 1956, an additional 6,480 linear feet of revetment were placed at several locations with Federal funds.
1950, the levee was raised and strengthened, a new pump house built at NE 18th Street, bank protection placed and new tide box facilities were installed.
1956, emergency repair (revetment) of the levee was accomplished.
1959, the Army Corps of Engineers and the City of Portland blocked off the Peninsula drainage canal at NE Marine Dr, and south adjacent to the NE 18th Street pumping plant.
1960, the 142nd Ave. cross levee was built along with a gate well structure at the 5-66 inch barrel tide box.1961, a new pumping station was constructed at NE 172nd and Marine Dr.
1962, an interceptor toe drain at NE 96th and Marine Dr. was constructed.
1963 - 2007, 37,250 linear feet of revetment was constructed at 10 locations.
1989, a pumping plant was constructed at NE 191st and NE Airport Way
1997, MCDD landowners passed an $8.3 million bond measure for capital improvements to the pumping plants, levees and operational facilities.
1997 - 1999, the NE 18th and NE 172nd primary pump plants capital improvements were completed, included electrical switchgear, discharge piping, automated trash raking system, telemetry and pumping capacity upgrades from 286,000 gpm to 522,000 gpm.
2000, upgraded the Broadmoor and Elrod Dr. internal pumping plants.
2000, upgraded the operational facilities and construction equipment.
2000 - 2001, the MCDD office was designed and constructed to support administrative and emergency command functions.
2000, MCDD received funding from the Army Corps of Engineers to dredge 7.5 miles of the upper Columbia Slough for environmental restoration and flood control benefits.
2003, reconstructed and upgraded the Broadmoor pumping plant.
2007, relocated and upgraded the NE 181st pumping plant.
2007, reinforced the NE 18th Peninsula levee plug between MCDD and PD2.
2007, 495 trees and root systems removed from the critical section of the levee along the NE 18th levee and a maintenance access road was constructed on the west side of the levee.
2007, MCDD contracted with the Army Corps of Engineers to recertify the levees and pumping plants for FEMA’s FIRM program. Certification approved by FEMA.
PERTINENT DATA Top Elevation of the levees (in feet NGVD 29) East End West End
Columbia River 44.0’ 37.0’
142nd Ave. - Cross Levee 41.2’
NE 223rd - Cross Levee 44.0’
NE 18th - Peninsula Cross Levee 35.5’
Prelim, Peak Flood. El (in feet NGVD 29) at the Midpoint of Levee
10-yr. 50-yr 100-yr 500-yr Levee Design Flood
23.5’ 27.3’ 28.9’ 33.1’ 34.3’
* These elevations taken from NPP Publications; Drainage District Condition Study on Safe Water Surface Elevations, May 1978.