Project Summary

The Newcastle Railroad Embankment was constructed as part of the railroad line which transported coal from Newcastle to Seattle during the 19th and early 20th centuries. The embankment is 55 feet tall and 150 feet long. May Creek Trail is located on top of the embankment.  Newport Hills Creek flows under the embankment in a long culvert.  A vertical pipe, called a standpipe, was attached to the upstream end of the culvert at least 40 to 50 years ago. The purpose of the standpipe was to create a small pond. The standpipe is not functioning properly, which is causing the pond level to increase.

Phase 1 of the project removed the failing standpipe and installed a new standpipe at the same location.  Phase 1 construction was completed in October 2020. Phase 2 of the project will remove the standpipe and culvert to restore free flow and fish passage to Newport Hills Creek. Newcastle refers to this project as S-017.

Contact Project Manager Brian Miller, [email protected], with questions. 
 Pond Diagram

 

Embankment Diagram

Project Location

Project Location

Background

Current Conditions
Current Conditions


Located within May Creek Park, the Railroad Embankment over Newport Hills Creek (embankment) is a historic railroad bridge built and used during Newcastle's coal-mining era. Under the embankment Newport Hills Creek flows through a 24" clay vitrified pipe culvert that is approximately 212 feet long. Flow into the culvert is obstructed by a primitive control structure (standpipe), which created an artificial pond on the north side (upstream) of the embankment. When water in the pond is at the level of the standpipe, the pond holds 15 acre-feet of water. If the pond level were to reach the top of the embankment the pond would hold 120 acre-feet of water, the equivalent of 60 Olympic-sized swimming pools. If the embankment were to breach or fail, the water would travel for 800 feet downstream to May Creek, and then for another 2.5 miles before it reaches Lake Washington.

The embankment is considered a dam and is on Washington State's dam inventory. A periodic inspection by Washington State Department of Ecology's Dam Safety Office (DSO) in 2018 indicated that the embankment is in poor condition. Over the past few years the standpipe has become blocked, which has caused dramatic increases and decreases in the pond depth. The design of the standpipe is unknown. As a result, the pond depth dramatically increased during the December 2019 and the February 2020 storm events. Due to the unknown construction and stability of the embankment, combined with the inability to control the pond depth, action must be taken to prevent a catastrophic failure of the embankment.  The City was awarded a FEMA High Hazard Potential Dams (HHPD) grant in both 2019 and 2020 for this project.

Phase 1 improvements were completed in October 2020 to address the immediate concern of the blocked outfall standpipe.  The new standpipe features an improved outflow along with a debris cage to prevent blockage. 

Plan & Estimated Timeline

The S-017 Project Consists of Two Phases

Phase 1

Phase 1 removed the failing standpipe and installed a new standpipe at the same location.  Phase 1 construction was completed in October 2020. The new standpipe is approximately 7 feet shorter than the existing standpipe causing the pond size to be reduced.

Link to Project Update Slides (PDF, 9.4 MB)  following completion of Phase 1 construction.


Phase 2
Phase 2
Phase 2 will remove the standpipe and culvert to restore free flow and fish passage to Newport Hills Creek. The pond will be eliminated and the area immediately upland of the embankment will be restored. It will also involve partial or full removal of the embankment. As a result, the existing trail will have to be relocated. Final design for Phase 2 will being in 2022 and is scheduled for completion in 2023.  Construction of Phase 2 is dependent of available finding.  It is anticipated that a significant majority (at least 2/3) of the construction cost will be grant funded.

What's Next?

Partners and Funding Support

King County Office of Emergency Management
Federal Emergency Management Agency (FEMA)
Washington State Department of Ecology

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