Alternative 2: Install Levee or Floodwalls

Alternative 2 will regulate the water level within the roadway by implementing one of the following options.

• Earthen Embankment Levee: This option would incorporate an elongated earthen embankment spanning the east and west sides of 148th Avenue Southeast. The existing pedestrian path will be raised to serve as an earthen embankment/dam.
• Flood Wall: Similar to the option above but with low-height retaining walls to support the raised embankment to minimize wetland impacts. This flood wall will span the east and west sides of 148th Avenue Southeast, with the pedestrian path located on top.

Alternative 2 would also include replacement of the culvert at the north end of 148th Avenue Southeast with a fish-passable culvert.

Construction impacts

The levee or floodwall alternative would temporarily impact traffic on 148th Avenue Southeast. Construction would occur in sequence on the northbound or southbound sidewalks to minimize traffic impacts. During construction of the raised paths, pedestrian traffic would be rerouted to the opposite side of the street. A single lane of traffic would need to be closed during construction. During the installation of the culvert, the roadway would be reduced to a single lane in each direction as the culvert is installed in phases.

Potential results

Alternative 2 would provide relief to flooding; however, due to the nature of the existing median and roadway layout, it is likely that pump systems would need to be installed in the median to remove any excess water. This alternative would have higher maintenance costs.