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HomeMy WebLinkAboutBaseline Monitoring Report_02022021.pdf
214 E GALER STREET, SUITE 300
S EATTLE, WA 9 8102
20 6.233.9 639 MAIN
86 6.727.0 140 FAX
P BS US A.CO M
Baseline Monitoring Report
Dale Walker Property
3400 East Valley Road
Renton, Washington 98057
Prepared for:
Dale Walker
555 SW Grady Way
Renton, Washington 98057
February 2, 2021
PBS Project 41482.000
Baseline Monitoring Report
Dale Walker
3400 East Valley Road
Renton, WA 98057
i
February 2, 2021
PBS Project 41482.000
Table of Contents
1 INTRODUCTION ........................................................................................................................................... 1
2 GOALS, OBJECTIVES, AND SUCCESS CRITERIA .......................................................................................... 1
2.1 Performance Standards ........................................................................................................................................................... 1
3 STATUS OF MITIGATION ............................................................................................................................. 1
4 METHODS ..................................................................................................................................................... 2
5 AS BUILT MITIGATION PLAN ...................................................................................................................... 2
6 BASELINE SAMPLING RESULTS ................................................................................................................... 2
7 BASELINE MONITORING OBSERVATIONS ................................................................................................. 3
8 MANAGEMENT RECOMMENDATIONS ...................................................................................................... 4
9 LIMITATIONS ................................................................................................................................................ 4
10 REFERENCES ................................................................................................................................................. 5
Supporting Data
TABLES
Table 1. Performance Standards
Table 2. Planted Vegetation Results
Table 3. Invasive Species Coverage
Table 4. Baseline Assessment Performance Standard Results
FIGURES
Figure 1. Site Vicinity Map
Figure 2. Vegetation Sampling Plots and Photopoints
APPENDICES
Appendix A: Site Photographs
Appendix B: Baseline Monitoring Datasheets
©2021 PBS Engineering and Environmental Inc.
Baseline Monitoring Report
Dale Walker
3400 East Valley Road
Renton, WA 98057
1
February 2, 2021
PBS Project 41482.000
1 INTRODUCTION
This Baseline Mitigation Monitoring Report has been prepared to document completion of the required
mitigation activities for the Dale Walker property located at 3400 East Valley Road in the City of Renton. The
project location is provided as Figure 1. Restoration of the wetland and buffer areas were triggered following
unpermitted clearing activities in 2017. Vegetation clearing extended across a wetland at the east edge of the
site onto the Washington State Department of Transportation (WSDOT) right-of-way for State Route 167. The
proposed mitigation plan was described in the “Critical Areas Report for the Dale Walker Property” dated June
2018 by PBS Engineering & Environmental Inc.
According to the approved Mitigation Plan, further details regarding data collection methodologies and
circular plot installation protocols would be described in the Baseline Monitoring Report and are included in
Section 4.
2 GOALS, OBJECTIVES, AND SUCCESS CRITERIA
The overall goal is to restore the functionality of the wetland and buffer through native plantings, control of
invasive species, and removal of contaminated fill material. Over time, this will provide an increase in available
habitat for species in the urban corridor.
2.1 Performance Standards
Table 1 shows the approved performance standards that will be used to measure restoration success in the
buffer.
Table 1. Performance Standards
Parameter
Thresholds
Year 1 Year 3 Year 5
Survival of planted trees 100% 80% 70%
Survival of planted shrubs/ferns 100% 80% 70%
Plant diversity - # of native species >6 >6 >6
Percent cover invasives1 0% >10% >10%
1. Invasives include Japanese knotweed, Himalayan blackberry, and any other species listed on the King
County noxious weed list. Reed canarygrass is ubiquitous in this area and control to 0% is likely not
feasible.
3 STATUS OF MITIGATION
Planting of the restored wetland buffer was completed in December 2020. Mitigation monitoring reports will
be due to the City before the end of each calendar year in Years 1 (2021), 2 (2022), 3 (2023), and 5 (2025). All
planted material is under warranty for one year. If any plant mortality is observed during the Year 1
monitoring, these individuals will be replaced by the landscape contractor during the planting window
(October 1 – March 1). Weeding and removal of invasive species will occur at least twice a year during the
monitoring period. Native volunteers will not be removed.
Baseline Monitoring Report
Dale Walker
3400 East Valley Road
Renton, WA 98057
2
February 2, 2021
PBS Project 41482.000
4 METHODS
The baseline monitoring visit occurred on January 18, 2021. Vegetative sampling, photographic monitoring
points, and general site observations were used to evaluate the mitigation area.
Percent survival of installed plants and plant diversity (Performance Standards 1 – 3) was calculated by
counting and identifying all plants within the mitigation area. The number of installed trees, shrubs, and ferns
will serve as the baseline for the remainder of the monitoring period.
A total of six 10-foot radius plots identified by wood stakes were identified to evaluate percent cover of
invasive species.
See Figure 2 for locations of plots and photo points. Baseline photos were taken at the established points.
Additionally, the area was reviewed to determine the baseline conditions of mulch placement and removal of
existing non-native plants.
5 AS BUILT MITIGATION PLAN
During the baseline monitoring visit, plant species, size, and quantities were verified against the approved
wetland buffer planting plan. All approved species and quantities were accounted for, with the exception of
two substitutions: Oregongrape (Mahonia aquifolium, FACU) was replaced with Cascade Oregongrape (M.
nervosa, FACU), and swordfern (Polystichum munitum, FACU) was replaced with deer fern (Blechnum spicant,
FAC). Cascade Oregongrape and deer fern are both native species and have a similar wetland indicator status
to the proposed species. Plants were installed correctly in the restoration area in the approximate location as
shown on the planting plan.
6 BASELINE SAMPLING RESULTS
Table 2 shows the number of counted plants by species. Table 3 provides the invasive species cover estimates
at each of the six plots. Table 4 compares the baseline sampling results to the approved performance
standards.
Table 2. Planted Vegetation Results
Species (Scientific Name) Planted
Planted Trees
Vine maple (Acer circinatum) 20
Red alder (Alnus rubra) 10
Beaked hazelnut (Corylus cornuta) 15
Bitter cherry (Prunus emarginata) 10
Douglas fir (Pseudotsuga menziesii) 16
Western red cedar (Thuja plicata) 14
TOTAL TREES (PLANTED) 85
Planted Shrubs and Ferns
Deer fern (Blechnum spicant) 50
Low Oregon grape (Mahonia nervosa) 40
Nootka rose (Rosa nutkana) 40
Snowberry (Symphoricarpos albus) 40
TOTAL SHRUBS/FERNS (PLANTED) 170
Baseline Monitoring Report
Dale Walker
3400 East Valley Road
Renton, WA 98057
3
February 2, 2021
PBS Project 41482.000
Table 3. Invasive Species Coverage
Plot # Invasive Species
Coverage Estimate
1 0.0%
2 0.0%
3 0.0%
4 0.0%
5 0.0%
6 0.0%
AVERAGE 0.0%
Table 4. Baseline Assessment Performance Standard Results
Parameter Thresholds Baseline Assessment
Results Year 1 Year 3 Year 5
Survival of planted trees 100% 80% 70% 100%
Survival of planted shrubs/ferns 100% 80% 70% 100%
Plant diversity - # of native species >6 >6 >6 10
Percent cover invasives 0% >10% >10% 0.0%
Percent cover native species N/A 7.8%
Percent cover herbaceous species N/A 25.0%
Survival of planted trees, shrubs, and ferns were calculated at 100%. A total of 10 native species were
observed in the mitigation area, exceeding the requirement of six native species. Recent plant installation and
mulch placement has resulted in an invasive species coverage of 0.0%.
During establishment of vegetation plots, percent cover of native and herbaceous species was collected and
was measured at 7.8% and 25.0%, respectively. The raw data can be found in Appendix B.
7 BASELINE MONITORING OBSERVATIONS
The following observations were made by PBS during the baseline monitoring field work.
· Tree and shrub placement was consistent with the approved planting plan. All species and quantities
were accounted for, with swordfern (Polystichum munitum) substituted with deer fern (Blechnum
spicant).
· Mulch was installed around the base of each installed plant.
· Tree stakes were installed for deciduous trees.
· Overall, the installed plants look healthy and are expected to establish well.
Baseline Monitoring Report
Dale Walker
3400 East Valley Road
Renton, WA 98057
4
February 2, 2021
PBS Project 41482.000
8 MANAGEMENT RECOMMENDATIONS
The management recommendations identified below are based on the baseline assessment field visit.
· Install tree stakes on all trees. The small conifers were installed without tree stakes, and several
individuals were leaning to one side.
· No invasive species management is required at this time. However, herbaceous species should be
removed from the mulch ring of installed plants.
· Assess plant health and irrigation needs. Implement watering schedule and assess need for irrigation
based on plant health and mortality.
9 LIMITATIONS
This report has been prepared for the exclusive use of the addressee and regulatory agencies. The opinions,
comments, and conclusions presented in this report were based upon information derived from our field
investigation and subsequent literature review. Conditions between, or beyond, our data plots may vary from
those encountered. Seasonal variations in soil moisture and vegetation are commonly encountered. Therefore,
results from subsequent surveys may not be identical to those presented in this report. No warranty,
expressed or implied, exists on the information presented in this report.
All of these style recommendations should be treated as default and ideal. There are, of course, situations
where adjustments can and need to be made to accommodate a document’s unique needs.
Baseline Monitoring Report
Dale Walker
3400 East Valley Road
Renton, WA 98057
5
February 2, 2021
PBS Project 41482.000
10 REFERENCES
PBS Engineering and Environmental. 2018. Critical Areas Report for the Dale Walker Property, Renton,
Washington. PBS Engineering and Environmental, Seattle, Washington.
Pojar J. and A. MacKinnon. 2004. Plants of the Pacific Northwest Coast - Revised. Lonepine Publishing.
USDA Natural Resources Conservation Service. 2019. Plants National Database. Accessed online at:
http://plants.usda.gov/java/
Washington State Department of Ecology. 2006. Wetland Mitigation in Washington State – Part 2: Developing
Mitigation Plans. 06-06-011b. Olympia, Washington.
WTU Herbarium Image Collection. 2019. Burke Museum of Natural History and Culture. Accessed online at:
http://biology.burke.washington.edu/herbarium/imagecollection.php
Figures
PROJECT VICINITY MAP
Dale Walker Property
Renton, WA
FIGURE
1 PROJECT #
41482
DATE
APRIL 2018
Project Site
N
400 ft
N➤➤N
PROJECT#41482.000 DATEJAN 2021
VEGETATION SAMPLING PLOTS AND PHOTO POINT LOCATIONSDale Walker Property3400 East Valley Road
FIGURE
2
PP 1
LEGEND
PLOT (1 - 6) 10' RADIUS
PHOTO POINT (PP) (1 - 9) AND DIRECTION
PP 2
PP 8
PLOT 6PP 9
PLOT 5 PP 7
PLOT 4 PP 6
PLOT 3PP 5
PLOT 2PP 4
PLOT 1PP 3
MITIGATIONAREA
Appendix A
Site Photographs
Photo point 1 Photo point 2
Photo point 3 Photo point 4
Photo point 5 Photo point 6
Photo point 7 Photo point 8
Photo point 9
Appendix B
Baseline Monitoring Datasheets
CountPercent CoverageCountPercent CoverageCountPercent CoverageCountPercent CoverageCountPercent CoverageCountPercent CoveragePlanted Trees
Vine maple (Acer
circinatum )1 1.0% 2 2.0%
Red alder (Alnus rubra )1 9.0%
Beaked hazelnut (Corylus
cornuta )
Black cottonwood
(Populus balsamifera)
Bitter cherry (Prunus
emarginata )
Douglas fir (Pseudotsuga
menziesii )
Western red cedar (Thuja
plicata )1 2.3%
Planted Shrubs and Ferns
Deer fern (Blechnum
spicant )1 1.0% 4 4.0% 3 3.0% 4 4.0%
Low Oregon grape
(Mahonia nervosa )6 6.0% 6 1.5% 5 1.3%
Nootka rose (Rosa
nutkana )6 6.0% 6 6.0%
Snowberry
(Symphoricarpos albus )
PERCENT WOODY
COVERAGE 9.3% 11.0% 6.0% 3.5% 4.3% 13.0%
AVERAGE PERCENT
COVERAGE
Herbaceous Cover 40.0% 20.0% 25.0% 30.0% 20.0% 15.0%
AVERAGE HERBACEOUS
COVER 25.0%
Plot 5 Plot 6
7.8%
Plot 4Plot 1 Plot 2 Plot 3