HomeMy WebLinkAboutC_KC_Second_Response_Letter_to_MIT_181022.pdfL-9
King County
Department of Natural Resources and Parks
Parks and Recreation Division
King Street Center
201 South Jackson Street, Suite 700
Seattle, WA 98104
October 22, 2018
Clark H. Close
Senior Planner
City of Renton
Subject: LUA18-000421, ECF, SMC
County Response to Muckleshoot Concerns (additional comments)
Dear Mr. Close:
Thank you for the opportunity to respond to additional comments regarding the County's permit
application to improve the trestle over May Creek for non -motorized use. We provide some brief
responses to the individual comments below. However, our overall response is focused on the limited
scope of the proposed decking project.
General response: As described in our prior response, decking the bridge is a minor change to existing
conditions that would have minimal effect on stream habitat. In itself, the decking does not constitute a
significant impact that would indicate anything beyond a DNS finding under SEPA. Given the limited
scope and cost of the project, which does not extend the overall life the trestle, the proposed work
would not reasonably trigger the removal and replacement of the entire trestle.
Responses to revised comments:
Creosote and aquatic habitat: Creosote has a negative impact on aquatic habitat, which tends
to decrease over time. The proposed project, while not removing the impact, would likely
reduce the transport of PAH's to the stream due to the reduction in runoff traveling along the
treated members during rainfall events. The suggested mitigation for creosote impact —
complete removal of the structure is not in proportion to the scope and scale of the project. It is
not the case that minor updates to existing structures with creosote piers throughout the Puget
Sound basin result in a requirement to remove the entire structure to mitigate creosote
impacts.
Scour: The current project does not include armoring, and we have no indication that scour is a
problem that would require future armoring.
■ Large woody debris: The upstream elements described in the County's previous response are
likely to be in place for the foreseeable future, and limit the likelihood that large woody debris
would be transported to the trestle. It is not within the scope of the project to consider the
removal or modification of these elements.
• Shading: Quantity of shading was addressed previously. The new issue raised in the comments
is the character of the shading. Note that the trestle currently has one continuous edge where
the pedestrian walkway is located. The height of the trestle above the creek, the presence of
existing large trees that filter and break up sunlight, the presence of proposed fencing that
breaks up sunlight, and the complexity of the substructure all mitigate the concern that the new
decking will create a cleanly defined sun/shade line. Solar access to the creek is filtered and
varied by the several levels and complexity of shading elements adjacent to and above the
trestle and we do not believe that impacts are significant enough to warrant a SEPA DS or a
requirement for substantial mitigation.
Sincerely,
William (Chris) Erickson
Project Manager
King County Parks