BLD2020-1313+Stream Report+4.27.2021_6.56.07_AM+2165386TECHNICAL MEMORANDUM
Date: April 26, 2021
To: Mary O'Driscoll
From: Grace Brennan, Ecologist
Project Name: Edmonds O'Driscoll
2 THE
WATERSHED
COMPANY
Project Number: 210142
Re: O'Driscoll Property Stream Reconnaissance Report
On March 15, 2021, Ecologist Grace Brennan visited the property located at 739 Elm Place
(parcel #00642200000600) in the City of Edmonds, Washington to screen for jurisdictional
streams. Site findings were reviewed by Senior Ecologist, Nell Lund. This letter summarizes the
stream findings of the study and associated City of Edmonds regulations.
The following document is enclosed:
• Reconnaissance Sketch
Summary
One stream, Willow Creek, is present on the study area. The onsite segment of Willow Creek is
classified as a non -fish habitat seasonal stream, Type Ns water. The City of Edmonds requires a
40-foot buffer for Type Ns waters. This assessment is limited to review and classification of the
City -mapped stream.
Per your description, relocation of the south property fence to place it along the surveyed
property line is planned. This removal and replacement of fencing over the stream is not a
significant change in the existing site condition or character of the onsite stream segment.
Methodology
The study area was evaluated for streams based on the presence or absence of an ordinary high
water mark (OHWM) as defined by Section 404 of the Clean Water Act, the Washington
Administrative Code (WAC) 220-660-030, and the Revised Code of Washington (RCW)
90.58.030. The mapped stream was classified per Edmonds Municipal Code (EMC
23.90.010.A.1) and WAC 222-16-030.
Public -domain information on the subject property was reviewed for this study and includes
the following:
750 Sixth Street South I Kirkland, WA 98033 1 P 425.822.5242 1 f 425.827.8136 watershedco.com
The Watershed Company
O'Driscoll Stream Classification Study
April 26, 2021
Page 2 of 6
• USDA NRCS: Web Soil Survey
• WA DNR Forest Practices Application Mapping Tool (DNR FPARS)
• City of Edmonds GIS Map Viewer
• Snohomish County Planning Development Services GIS Map (PDS Map)
Characterization of climatic conditions for precipitation was determined using the WETS table
methodology from the USDA NRCS document Part 650 Engineering Field Handbook, National
Engineering Handbook, Hydrology Tools for Wetland Identification and Analysis, Chapter 19
(September 2015). The Seattle -Tacoma International AP station as recorded by NOAA
(http://agacis.rcc-acis.org/) was used as a source for precipitation data. The WETS table
methodology uses climate data from the three months prior to the site visit month to determine
if normal conditions are present.
The area was not evaluated for the presence/absence of wetlands.
Findings
The subject property is within in the Middle Puget Sound — Shoreline sub -basin of the Cedar —
Sammamish watershed (WRIA 8); Section 25 of Township 27 North, Range 03 East of the Public
Land Survey System. Surrounding land use is categorized high intensity residential areas.
The parcel is currently developed with a single-family home and associated yard and driveway.
Parcels immediately to the north, south, and west are developed with single-family residences.
Immediately east of the property is the terminal of Elm Place. The residence is on a moderate
slope above and east of a channel. The site slopes down to the northwest. The majority of the
site is maintained as a residence and associated yard, and is primarily vegetated by a
maintained lawn, along with a variety of ornamental species.
Stream A
Stream A, or Willow Creek, runs north through the study area, originating from a stormwater
outfall at the eastern boundary of the property south of the subject parcel. An additional
stormwater pipe that is mapped connecting to a stormwater drain at the end of Elm Place to the
Stream A, which comes in at the southern boundary of the subject property (Figures 1 and 2).
While a majority of the hydrology of this feature appears to originate from stormwater inputs, it
is likely that this stream channel was an existing natural stream prior to development and not
wholly created for stormwater infrastructure. Stream flows are seasonal.
The Watershed Company
O'Driscoll Stream Classification Study
April 26, 2021
Page 3 of 6
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Figure 1. Stream and stormwater map for vicinity of subject parcel. Subject parcel outlined in purple.
The Watershed Company
O'Driscoll Stream Classification Study
April 26, 2021
Page 4 of 6
Figure 2. On -site stormwater inputs at southern edge of the study area.
The segment of Stream A within the subject parcel is primarily vegetated with watercress
(Nasturtium officinale), reed canarygrass (Phalaris arundinacea), and creeping buttercup
(Ranunculus repens). The stream channel is heavily armored in the southern portion of the
property, with concrete blocks lining the edge. The substrate in the upstream segment of the
stream channel appears to be imported gravel and cobble. The on -site segment of the stream
channel is approximately 1.5 feet wide on average. The channel both upstream and downstream
of the subject parcel appear to be slightly wider than the on -site segment and show evidence of
manmade modifications. Given landscape position in the headwaters of this stream, low flow
conditions as evidenced by the vegetated channel condition, and narrow on -site channel width,
this stream segment is presumed non -fish -bearing.
Existing chain link fencing crosses the stream at the east and northwest property lines. The
fences are elevated a few feet above the channel and do not appear to impact riparian habitat
functions. A replacement fence along the surveyed south property line is not expected to alter
the character or function of the stream corridor.
The Watershed Company
O'Driscoll Stream Classification Study
April 26, 2021
Page 5 of 6
Figure 3. On -site segment of Willow Creek.
Figure 4. Up -stream segment of Willow Creek. Yellow line denotes southern parcel boundary.
The Watershed Company
O'Driscoll Stream Classification Study
April 26, 2021
Page 6 of 6
The onsite segment of Stream A is a seasonal water that is presumed non -fish -bearing. It is a
Type Ns water per City of Edmonds code (ECC 23.90.10). Type Ns streams in the City of
Edmonds require a 40-foot buffer.
Disclaimer
Please note: The information contained in this email 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 in good faith, 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 warranty,
expressed or implied, is made.
Should you have any questions or concerns regarding our findings, please feel free to contact
me.
Sincerely,
Grace Brennan
Ecologist
Nell Lund, PWS
Senior Ecologist / Professional Wetland Scientist #2203
Enclosures
THE
WATERSHED
COMPANY
750 Sixth Street South I Kirkland I WA 98033
p 425.822.5242 f 425.827.8136
Stream Reconnaissance Sketch — O'Driscoll Property
Site Address: 739 Elm Place, Edmonds Prepared for: Mary O'Driscoll
Parcel Number: 00642200000600 TWC Ref. No.: 210142
Site Visit Date: 3/15/2021
Note: Field sketch only. Features depicted are approximate and not to scale. All observations were made from within the study
area and neighboring property to the south; adjoining private properties without access were not entered.
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