HomeMy WebLinkAboutRS_Stream Buffer Restoration Plan_New Life_240402_v1.pdf
March 4, 2024
AOA-6644
John Kay
john@kplusarchitects.net
SUBJECT: New Life Church Frontage Improvements Stream Buffer Restoration
15711 -152nd Ave. SE, Renton, WA (Parcel 232305-9021)
Dear John:
We have prepared the attached stream buffer restoration plan (W1 through W4) for
unavoidable temporary impacts to the buffer of Madson Creek associated with the
installation of a utility line within the Maple Valley Highway (SR 169) right-of-way.
1.0 EXISTING CRITICAL AREAS
Madson Creek flows from east to west south of the required frontage improvements
and utility line installation. The ordinary high water (OHW) of the north side of the
creek was delineated on January 25, 2024 and was subsequently surveyed.
Madson Creek is a Type F stream and requires a standard 115-foot buffer. The 115-
foot buffer from the stream extends north through the right-of-way and SR 169. No
wetlands were observed adjacent to the creek.
2.0 TEMPORARY BUFFER IMPACTS AND CRITICAL AREA RESTORATION
Following installation of the utility line all temporarily disturbed buffer areas will be
restored and enhanced with native vegetation. Most of the disturbed area in the
eastern portion of the right-of-way is mowed grass, while the western portion of the
disturbance area was dominated primarily by Himalayan blackberry (Rubus
armeniacus) with patches of native shrubs.
2.1 Goal, Objectives, and Performance Standards for Restoration Area
The primary goal of the restoration plan is to restore and enhance the stream buffer
that will be temporarily impacted by the utility line installation. To meet this goal, the
following objectives and performance standards have been incorporated into the
design of the plan:
John Kay March 4, 2024 Page 2 of 3
Objective A: Increase the structural and plant species diversity within the restoration
areas.
Performance Standard: There will be 100% survival of all planted species throughout
the restoration areas at the end of the first year of planting. Following Year 1,
success will be based on an 80% survival rate and areal cover of planted or
recolonized native species of 15% after Year 1, 20% after Year 2, 30% after Year 3,
and 50% at Year 5.
Objective B: Limit the amount of invasive and exotic species within the restoration
areas.
Performance Standard: After construction and following every monitoring event for a
period of at least five years, exotic and invasive plant species will be maintained at
levels below 10% total cover in all planted areas.
2.2 Construction Management
Prior to commencement of any work in the restoration areas, the clearing limits will
be staked and all existing vegetation to be saved will be clearly marked. A
consultant will supervise plan implementation during construction to ensure that
objectives and specifications of the mitigation plan are met. Any necessary
significant modifications to the design that occur as a result of unforeseen site
conditions will be jointly approved by the City of Renton and the consultant prior to
their implementation.
2.3 Monitoring Methodology
The monitoring program will be conducted for a minimum period of five years, with
reports submitted quarterly in the first year and annually thereafter to the City of
Renton following plan implementation.
Although the entire restoration area will be reviewed, permanent vegetation sampling
plots or transects will be established to incorporate all of the representative plant
communities. The same monitoring points will be re-visited each year with a record
kept of all plant species found. Vegetation would be recorded on the basis of
relative percent cover of the dominant species within the vegetative strata.
Photo-points will be established from which photographs will be taken throughout the
monitoring period. These photographs will document general appearance and
progress in plant community establishment in the restoration areas. Review of the
photos over time will provide a visual representation of the success of the mitigation
plan.
2.4 Maintenance Plan
Maintenance should be conducted on a routine, year round basis. Additional
maintenance needs will be identified and addressed following the performance
monitoring site visits. Contingency measures and remedial action on the site shall
be implemented on an as-needed basis at the direction of the consultant or the
owner.
John Kay March 4, 2024 Page 3 of 3
Routine removal and control of non-native and other invasive plants (e.g., Himalayan
and evergreen blackberry, Japanese knotweed, purple loosestrife, English ivy,
morning glory, thistle and creeping nightshade) shall be performed by manual means
whenever possible. Undesirable and weedy exotic plant species shall be maintained
at levels below 10% total cover within any given stratum at any time during the five-
year monitoring period.
Routine maintenance of planted trees shall be performed. Measures include
resetting plants to proper grades and upright positions. Tall grasses shall be
weeded at the base of plants to prevent engulfment.
2.5 Contingency Plan
All dead plants will be replaced with the same species or an approved substitute
species that meets the goal of the restoration plan. Plant material shall meet the
same specifications as originally installed material. Replanting will not occur until
after the reason for failure has been identified (e.g., moisture regime, poor plant
stock, disease, shade/sun conditions, wildlife damage, etc.). Replanting shall be
completed under the direction of the wetland consultant, City of Renton, or the
owner.
2.6 As-built Plan
Following completion of the restoration plan, an as-built plan and baseline
assessment report for the restoration areas will be provided to the City of Renton.
The plan and report will identify and describe any changes in grading, planting or
other constructed features in relation to the original approved plan. The plan will
also depict locations of photo-points and vegetation sampling points to be used
during the performance monitoring period. The minimum 5-year mitigation
monitoring period will not begin until after the City reviews and approves the as-built
report and plan.
All of the statements and conclusions presented in this report are accurate to the best
of my knowledge. If you have any questions, please give me a call.
Sincerely,
ALTMANN OLIVER ASSOCIATES, LLC
John Altmann
Ecologist
Attachment