HomeMy WebLinkAboutC_Request_Response Memo_180522
May 22, 2018
Mr. Phil Olbrechts
Hearing Examiner
City of Renton
1055 S Grady Way
Renton, WA 98057
SUBJECT: City’s Response to Applicant Request to Remove Native Growth Protection
Easement over Wetland “A”, within the Hearing Examiner Report
King County Waste Water Treatment Plant / LUA18-000188, SA-A, CU-H, SME, MOD
Dear Mr. Olbrechts,
The Planning Division of the City of Renton received a request to remove specific portions of
Hearing Examiner Recommended Condition No. 4 found in of the Hearing Examiner Staff Report
(Exhibit 1), as it pertains to Wetland A. The request was received on May 11, 2018 and included
343 pages of supporting material to the applicant’s request (enclosure). The updated Wetland
Assessment Report (May 2018) concluded that upon further investigation, including review of
historic aerial photos and discussion with King County Wastewater Treatment Division staff
regarding past South Treatment Plant activities, Wetland A was determined not to meet the
regulatory definition of a wetland under Renton Municipal Code (RMC) 4-3-050B.1.
According to the Report, the project area was landscaped after being used for staging during
several different previous projects at the treatment plant and is outside of a riparian corridor and
was not restored as project mitigation. The landscaped area that extends along the east and south
sites of the HERB project site was investigated with four data plots; locations for DP1, DP2, DP3 ,
and DP4. The area around data plot DP3 was created as a landscape amenity for the wastewater
treatment facility in a location that was poorly drained due to previous soil compaction. Plants
tolerant to poorly drained conditions were installed during land scaping. Based on the young age
of the trees and shrubs, and the constructed nature of the landscaped area, it was found that this
area is only recently developing wetland characteristics due to past development activities. The
applicant found that the project area has been reworked many times over in the last 30 years and
conditions are considerably different than the natural state. Water ponds on the compacted soil
and remains in the area until evaporated or transpired by plants, causing wetland condition s to
Mr. Olbrechts
Page 2 of 2
May 22, 2018
develop in this artificially created feature. This wet area was also found to be isolated from any
downslope wetlands and streams.
Review of the aerial imagery (Google Earth) shows that in 1990 this entire area was an open field.
In the mid-1990s, this area was used for heavy equipment staging during the plant’s secondary
treatment upgrade. An aerial image from 2002 shows relatively new landscaping including
grading, construction of a pathway, and planting of trees. This series of aerial photos shows that
the landscape was altered in the past, including stockpiling of spoils from other projects in the
center of the field, used as a staging area for construction, including construction of a walking path
and planting of trees and shrubs. The applicant concludes that the landscaped wet area (date plot
DP3), containing wetland conditions, is not a regulated wetland under RMC. Staff concurs with
the applicant’s analysis of Wetland A based on the findings of the updated Wetland Assessment
Report and, as a result, staff recommends a revised Recommended Condition No. 4 as follows:
4. A Native Growth Protection Easement (NGPE) shall be recorded over the top of Wetland B and
associated buffers. The NGPE shall be submitted with the construction permit application to be
reviewed and approved by the Current Planning Project Manager prior to construction permit
approval.
Please contact me at (425) 430-7289 if you have any questions.
Sincerely,
Clark H. Close
Senior Planner
Enclosure: King County Waste Water Treatment Plant Request dated May 11, 2018
cc: Chris Dew / Contact
Martin, Muscaci / Parties of Record