21-101917-Wetland Delineation-07-21-2014-V1
July 21, 2014
Ed Kim
Hotel Concepts, Inc.
2200 – 6th Ave., Ste 520
Seattle, WA 98121-1820
Via email: edkim@hotelconcepts.us
Re: Steel Lake Stream and Wetland Delineation Review Study
The Watershed Company Reference Number: 140508
Dear Ed,
This letter summarizes the findings of the Wetland and Stream Delineation Review
Study conducted at Steel Lake, 1931 South 304th Street in the City of Federal Way.
Ecologist Ryan Kahlo, PWS, and I met Jason Walker (Perteet) and Matt Herrera (City of
Federal Way) on-site July 2, 2014, to discuss discrepancies observed regarding the
previous delineation study and to establish priorities for the re-delineation site visit.
During the site visit, previously placed wetland boundary flags were checked for
accuracy and the ordinary high water mark (OHWM) of Redondo Creek and Steel Lake
were assessed. Changes to the prior stream and wetland boundaries are described
below. The following attachments are included:
Wetland Delineation Map with revisions
Methods
Existing documents regarding the proposed project as well as the previously-delineated
on-site wetland, Redondo Creek, and Steel Lake were reviewed for this study. Public-
domain information was also reviewed. These sources include USDA Natural
Resources Conservation Service Soil maps, U.S. Fish and Wildlife Service National
Wetland Inventory maps, Washington Department of Fish and Wildlife interactive
mapping programs (PHS on the Web and SalmonScape), Washington State Department
of Natural Resources Forest Practices Activity Mapping Tool (FPARS), King County’s
GIS mapping website (iMAP), and the City of Federal Way’s Shoreline Master Program
Documents.
The study area was evaluated for wetlands using methodology from the Regional
Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains,
Valleys, and Coast Region Version 2.0 (Regional Supplement) (US Army Corps of
Engineers [Corps] May 2010) and Western Washington Wetland Rating System (Ecology,
Steel Lake Stream and Wetland Delineation Review Study
Ed Kim
July 2014
Page 2
Aug 2004, revised 2006) (Rating System Guidance). The wetland boundary flags placed
by Raedeke Associates, Inc., in October 2012 were re-evaluated. The wetland boundary
was determined on the basis of an examination of vegetation, soils, and hydrology.
Areas meeting the criteria set forth in the Regional Supplement were determined to be
wetland. Soil, vegetation, and hydrologic parameters were sampled at several locations
along the wetland boundary to make the determination.
New wetland flags were placed where observable discrepancies in the original
delineation were noted by TWC and Perteet. The distance and compass bearing from
the location of the new flags to the location of the original flags were recorded in the
field. This information was used to edit the original delineation figure to more
accurately depict the wetland boundary (see Wetland Delineation Map).
The OHWM of Redondo Creek and Steel Lake were determined based on the definition
provided by the Washington Department of Fish and Wildlife and WAC 220-110-
020(69). The OHWM is located by examining the bed and bank physical characteristics
and vegetation to ascertain the water elevation for mean annual floods. Areas meeting
the definition were determined to be the OHWM.
Findings
Wetlands
Upon evaluation of the 2012 Raedeke delineation, TWC and Perteet determined that the
feature that was flagged as one large lake-shore wetland is two wetlands bisected by an
area that is instead characterized as the OHWM of Steel Lake due to a break in
hydrophytic vegetation. The Rating System Guidance for determining lake-shore
wetland units says to “…separate the vegetated parts into different units at the points
where the wetland vegetation thins out to less than a foot in width for at least 33ft
(10m)” (see also Figure 1). All of the wetland vegetation associated with the two lake-
shore wetlands is located at or below the OHWM of Steel Lake. The non-wetland area
contains no vegetation below the OHWM; the substrate is composed of an
unconsolidated gravel bed typical of the greater lake substrate. The topography in the
non-wetland area is also distinct, dropping off immediately from upland to lake-waters.
The break between wetland units occurs between flags 1-14 through 1-20. “Wetland A”
occurs west of this break and continues north along Redondo Creek. “Wetland B” is
located east of the vegetation break and continues off-site.
Steel Lake Stream and Wetland Delineation Review Study
Ed Kim
July 2014
Page 3
Figure 1. Example of where to break a lake-shore wetland into multiple units from the Rating
System Guidance.
Wetland A contains scrub-shrub, emergent, and aquatic bed Cowardin vegetation
communities. Dominant vegetation includes salmonberry, Pacific willow, hardhack
spirea, skunk cabbage, and duckweed. This wetland contains multiple
hydrogeomorphic classes including lake-fringe, riverine, and depressional. Surface
water and soil saturation were observed at several locations within the wetland during
the site visit.
Wetland B is characterized as a narrow lake-fringe wetland with scrub-shrub and
forested Cowardin vegetation communities. The main source of hydrology to this
wetland is Steel Lake. Dominant vegetation included Western red cedar in the canopy,
with spirea, salmonberry, and some Labrador tea in the understory.
Redondo Creek
Redondo Creek is broad and flows at a low gradient through the study area (from Steel
Lake north to South 304th Street). The OHWM of Redondo Creek appears to be largely
associated with, and very similar to, the level of Steel Lake. Furthermore, while
delineating Wetland A along the creek corridor, it was determined that the OHWM of
Redondo Creek coincided with the majority of Wetland A boundary flags (with the
exception of flag 1-45). This determination was based on the presence of nearby surface
water (presumably slow-moving Redondo Creek) during the site visit and the
topography of the area; Wetland A is almost exclusively located within bed and bank
features created by Redondo Creek.
Steel Lake Stream and Wetland Delineation Review Study
Ed Kim
July 2014
Page 4
There is a natural fish barrier located downstream of the study site (SalmonScape,
FPARS, communication with Matt Herrera) that prevents access to this portion of
Redondo Creek by anadromous fish species.
Steel Lake
The OHWM of Steel Lake is contiguous with the flagged boundaries of Wetlands A and
B. Between these wetlands, flags 1-14 through 1-20 also mark the OHWM of the lake.
Local Regulations
The City of Federal Way regulates wetlands and streams under Federal Way Revised
Code (FWRC), Chapter 19.165 “Streams” and Chapter 19.175 “Regulated Wetlands.”
Shorelines are regulated under Title 15, “Shoreline Management.”
Wetlands A and B are considered Category II wetlands per FWRC. Category II wetlands
require a standard buffer width of 100 feet.
Redondo Creek is considered a minor stream due to the natural fish barrier located
downstream of the project site. This classification corresponds with the City’s
assessment of the stream based on communication with Matt Herrera during the on-site
meeting. Minor streams require a standard buffer width of 50 feet.
Per 15.05.080 “Shoreline residential environment,” a minimum shoreline setback of 50
feet is required from the OHWM of Steel Lake. This setback is only relevant where no
wetland exists along the shore of Steel Lake (flags 1-14 through 1-20).
Disclaimer
The information contained in this letter or report is based on the application of technical
guidelines currently accepted as the best available science and in conjunction with the
manuals and criteria outlined in the methods section. All discussions, conclusions and
recommendations reflect the best professional judgment of the author(s) and are based
upon information available to us at the time the study was conducted. All work was
completed within the constraints of budget, scope, and timing. The findings of this
report are subject to verification and agreement by the appropriate local, State and
Federal regulatory authorities. No other warranty, expressed or implied, is made.
Steel Lake Stream and Wetland Delineation Review Study
Ed Kim
July 2014
Page 5
Please call if you have any questions or if we can provide you with any additional
information.
Sincerely,
Katy Crandall, WPIT
Ecologist
Enclosures