HomeMy WebLinkAboutRS_WTLD-2016-05-20-Altmann_Oliver
May 20, 2016
AOA-4982
John Everett
Denova Northwest, LLC
6830 S. 220th Street
Kent, WA 98032
SUBJECT: Wetland and Stream Reconnaissance on 2611 Union Ave. NE
Parcel 042305-9142, Renton, WA
Dear John:
On March 1, 2016 I conducted a wetland and stream reconnaissance on the subject
property utilizing the methodology outlined in the May 2010 Regional Supplement to
the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys,
and Coast Region (Version 2.0). The southeast corner of the site is developed with
a single-family residence. The remainder of the property is undeveloped except for
a large utility line corridor that traverses the far western portion of the site from south
to north. The area west of the utility corridor was not reviewed as part of the
reconnaissance since there was no proposed work in the vicinity of that area.
Existing Conditions
The project site outside of the existing residence consists of an upland forest that
slopes down from south to north. Vegetation consisted primarily of a canopy of big-
leaf maple (Acer macrophyllum) and Douglas fir (Pseudotsuga menziesii), with an
understory dominated by snowberry (Symphoricarpos albus), Himalayan blackberry
(Rubus armeniacus), Indian plum (Oemleria cerasiformis), hazelnut (Corylus
cornuta), and sword fern (Polystichum munitum). No hydrophytic plant communities
were observed.
Borings taken throughout the site revealed high chroma, dry, non-hydric soils. In
addition, there was no evidence of ponding or prolonged soil saturation on the
property during a field investigation conducted during a winter of above-average
precipitation.
John Everett
May 20, 2016
Page 2
Eastern Drainage
During the site review, runoff was observed discharging from the stormwater
conveyance system adjacent the Sierra Heights Elementary School off-site to the
south. This runoff is conveyed within a roadside ditch along the west side of Union
Ave. NE prior to conveyance through a well-defined channel in the northeast portion of
the subject property. Runoff within the on-site channel was observed infiltrating on the
slope during the field investigation and the channel did not extend to the north property
line.
This drainage on the site is not mapped as a stream on the City of Renton critical area
maps or on any WA State mapping system (i.e., SalmonScape or FPARS). Since the
drainage does not originate from a wetland and appears to convey only artificially
collected stormwater runoff it should not be regulated as a stream by the City of
Renton.
If you have any questions regarding the reconnaissance, please give me a call.
Sincerely,
ALTMANN OLIVER ASSOCIATES, LLC
John Altmann
Ecologist