SR 240 I-182 to Columbia Center Interchange (Columbia Causeway) Mitigation Site

USACE IP 2004-00043

South Central Region

2018 MONITORING REPORT

Wetlands Program

Issued March 2019

Environmental Services Office

Author: Jennie Husby

Editor: Kristen Andrews

Contributors: Kristen Andrews Jennie Husby Tom Mohagen Sean Patrick

For additional information about this report or the WSDOT Wetlands Program, please contact:

Kristen Andrews, Wetlands Program WSDOT, Environmental Services Office P. O. Box 47332, Olympia, WA 98504 Phone: 360-570-2588 E-mail: [email protected]

Monitoring reports are published on the web at: http://www.wsdot.wa.gov/environment/technical/disciplines/wetlands/monitoring- reports

SR 240 I-182 to Columbia Center Interchange (Columbia Causeway) Mitigation Site

USACE IP 2004-00043

General Site Information USACE IP Number 2004-00043 Ecology WQC 1760 On both sides of SR 240 at milepost 37 in Mitigation Location Benton County LLID Number 1192477462437 Construction Date 2005–2007 Monitoring Period 2009-2018 Year of Monitoring 10 of 10 Type of Impact Permanent Wetland Area of Project Impact1 9.65 acres Upland Wetland Wetland Type of Mitigation Vegetation Establishment Enhancement Preservation Planned Area of 10.19 acres 5.62 acres 0.7 acre Mitigation2

1 Impact and mitigation numbers sourced from SR 240, I-182 to Columbia Center Interchange Construct Additional Lanes Final Mitigation Plan Addendum (WSDOT 2008). 2 Additional off-site mitigation credit of 3.2 acres obtained from Amon Creek for fish passage enhancement and simulated stream channel construction.

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240 Columbia Causeway 3 2018 Annual Monitoring Report

Summary of Monitoring Results and Management Activities (2018)

2018 Results3 Performance Standards Management Activities East Unit West Unit

Wetland Delineation (15.79 acres wetland) 15.67 acres (See Appendix 4)

36% cover 41% cover

(CI80%= 28-43%) (CI80%= 25-56%)

50% cover native wetland trees and shrubs in the combined PSS and PFO (58% (CI80%= 47- (70% (CI80%= 57- 69%) if Lombardy 83%) if Lombardy poplar included) poplar included) 43% cover

(CI80%= 24-62%)

50% cover native wetland herbaceous plant species in the PEM (81% (CI80%= 66- 95%) if narrowleaf cattail included)

Five native tree and/or shrub species in the PSS/PFO Achieved

Three native herbaceous species in the PEM Achieved

49% cover 40% cover native plant species in the upland buffer (CI80%= 39-59%)

Three native plant species in the upland buffer Achieved

No Washington State-listed or county-listed Class A weeds None observed Weed control activity Control of Benton County-designated Class B and C weeds None observed occurred twice a month Less than 15% cover kochia (Bassia scoparia), puncturevine (Tribulus 10% cover common reed and Russian olive; from June through terrestris), common reed (Phragmites australis), prickly Russian thistle (Salsola no kochia, puncturevine, or prickly Russian September in 2018 tragus) and Russian olive (Elaeagnus angustifolia) combined across the site thistle observed

3 Estimated values are presented with their corresponding statistical confidence interval. For example, 36% cover (CI80% = 28-43%) means we are 80% confident that the true cover value is between 28% and 43%.

240 Columbia Causeway 1 2018 Annual Monitoring Report

Report Introduction

This report summarizes final-year (Year 10) monitoring activities at the 240 Columbia Causeway Mitigation Site. Included are a site description, the performance standards, an explanation of monitoring methods, and an evaluation of site success. Monitoring activities included vegetation surveys on photo-documentation July 30, August 1, and September 10, 2018, and a wetland delineation on April 12, 2017.

240 Columbia Causeway 2 2018 Annual Monitoring Report

What is the 240 Columbia Causeway Mitigation Site?

This 15.81-acre mitigation site (Figure 1) contains 10.19 acres of wetland establishment and 5.62 acres of wetland enhancement located on both sides of State Route (SR) 240 just south of the Yakima River. This site was created to compensate for the loss of 9.65 acres of wetlands due to the addition of lanes and a pedestrian/bike path from MP 63.26 and 37.59 and MP 37.84 and 38.71 along the SR 240 corridor between Richland and Kennewick in Benton County, WA. The recently established and enhanced emergent, scrub-shrub and forested wetlands are designed to provide mitigation for lost wetland functions including wildlife habitat, flood flow alteration, and contaminant buffering.

Figure 1 Site Sketch The 240 Columbia Causeway Mitigation Site is comprised of two sections, positioned on either side of SR 240. The long portion on the east side of the SR is located adjacent to the confluence of the Yakima River and the Columbia River (East Unit). A conveyance (wildlife tunnel) structure connects this portion of the site with a canal enhancement area on the west side of the SR (West Unit). In addition, a land purchase of 15.59 acres on Amon Creek compensates for an additional 3.2 credits of mitigation. Appendix 2 contains directions to the site.

240 Columbia Causeway 3 2018 Annual Monitoring Report

What are the performance standards for this site?

Year 10

Performance Standard 1 In the wetland establishment and enhancement areas, soils will be inundated or saturated to the surface, or groundwater will be present within 12 inches of the surface at least 20 consecutive days during the growing season in years when precipitation is equal to or greater than the 30-year average at the weather station nearest to the SR 240 mitigation site. Hydrology will be measured at 10 or more locations at or near the upland/wetland boundary.

The wetland boundary will be delineated using methods approved by the US Army Corps of Engineers and the Washington Department of Ecology to determine the area of wetland on site. Current approved methods are described in the Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (USACE 2008).

The designated establishment and enhancement areas at the SR 240 mitigation site will contain at least 15.79 acres of wetland. Wetland areas designated as “buffer” for regulatory purposes along the west edge of the East Unit are not included in the minimum required wetland area.

Performance Standard 2 Cover of native wetland trees and shrubs (planted and volunteer) will be at least 50 percent in the combined scrub-shrub and forested communities.

Performance Standard 3 Cover of native wetland herbaceous plant species (planted and volunteer) will be at least 50 percent in the emergent communities.

Performance Standard 4 There will be at least five native tree and/or shrub species present in the scrub-shrub and forested wetlands.

Performance Standard 5 There will be at least three native herbaceous species present in the emergent communities.

240 Columbia Causeway 4 2018 Annual Monitoring Report Performance Standard 6 Cover of native plant species (planted and volunteer) will be at least 40 percent in the upland buffer.

Performance Standard 7 There will be at least three native species present in the upland buffer.

Performance Standard 8 Washington State-listed or county-listed Class A weeds must be eradicated. All occurrences shall be immediately reported to the site manager and an eradication program will be initiated within 30 days of the report.

The following Class A weeds are of particular concern to the Benton County Noxious Weed Control Board (BCNWCB 2010): buffalobur nightshade (Solanum rostratum) and flowering rush (Butomus umbellatus).

Performance Standard 9 The following Class B and Class C weeds have been designated for control by the Benton County Noxious Weed Control Board (BCNWCB 2010). If any of the following species are found on the site during the monitoring period, occurrences shall be immediately reported to the site manager and control measures will be initiated within 30 days of the report: (See Appendix 3, Table 1).

Performance Standard 10 For the following weeds, combined cover will not exceed 15 percent across the mitigation site: burning bush, puncturevine, common reed, prickly Russian thistle, and Russian olive.

Appendix 1 shows the planting plan (Davari 2006).

240 Columbia Causeway 5 2018 Annual Monitoring Report How were the performance standards evaluated?

WSDOT staff collected hydrology data and performed a wetland delineation using methods described in the Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987), Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0) (USACE 2010) and a Global Positioning System (Trimble Mapping Grade) (Performance Standard 1).

Appendix 3, Table 2 documents the sample method used for all of the remaining performance standards (PS) as required by the mitigation plan. For additional details on the methods see the WSDOT Wetland Mitigation Site Monitoring Methods Paper (WSDOT 2008). Placement of Baseline: Parallel to SR 240 through the buffer in the East and West Units East Unit: Length 1,024m, Transects - 19 West Unit: Length 396m, Transects - 14

Figure 2 Site Sampling Design (2018)

240 Columbia Causeway 6 2018 Annual Monitoring Report Is this site a success?

This site is considered successful even though percent cover of native trees, shrubs, and herbaceous plants is lower than the performance standard thresholds. This determination is justified by the fact that non-native Lombardy poplar (Populus nigra), a dominant woody species in the wetland and common in the greater landscape of the Yakima River Delta, provides the same wetland functions as native woody tree species. If Lombardy poplar is included in the cover calculation, the percent cover standard would be easily met. This holds true for non-native narrowleaf cattail (Typha angustifolia) as well, as it is very common on the delta and provides the same wetland functions as native Typha latifolia. Cover of native species in the buffer is high. Wildlife habitat has increased throughout the site.

Diversity of native woody and herbaceous plant species has increased. Cover of invasive species is low. This, with the addition of organic soils, has enhanced flood flow alternation. This well-vegetated wetland successfully intercepts sediment and contaminants, increasing contaminant buffering.

240 Columbia Causeway 7 2018 Annual Monitoring Report Results for Performance Standard 1 (Wetland Delineation [15.79 acres wetland]):

A delineation conducted April 12, 2017 indicated wetland acreage was 15.67 acres (0.12 acre less than planned) (Appendix 4). Both the East and West Unit wetlands are contiguous with off-site wetlands and the delineated acreage represents WSDOT’s best information on the wetland mitigation site boundary.

Results for Performance Standard 2 (50% cover native wetland trees and shrubs in the combined PSS and PFO): Photo 1 Cover of native woody species in the East Unit is estimated Woody cover in the PSS/PFO (August 2018) at 36% (CI80%= 28-43) (Photo 1). This is below the performance standard target. If the non-native tree Lombardy poplar is included, cover is estimated at 58% (CI80%= 47- 69%).

Cover of native woody species in the West Unit is estimated at 41% (CI80%= 25-56%). This is below the performance standard target. If the non-native tree Lombardy poplar is included, cover is estimated at 70% (CI80%= 57-83%).

240 Columbia Causeway 8 2018 Annual Monitoring Report Results for Performance Standard 3 (50% cover native wetland herbaceous plant species in the PEM):

Cover of native herbaceous species in the emergent area is estimated at 43% (CI80%= 24-62%) (Photo 2). This is below the performance standard target. If non-native narrowleaf cattail is included, cover is estimated at 81% (CI80%= 66- 95%).

Results for Performance Standard 4 (Five native tree and/or shrub species in the PSS/PFO):

Five native tree and shrub species were observed in the combined scrub-shrub and forested wetland including: Pacific Photo 2 willow (Salix lasiandra), sandbar willow (Salix exigua), Herb cover in the PEM (August 2018) redosier dogwood (Cornus alba), golden currant (Ribes aureum), and gray alder (Alnus incana).

Results for Performance Standard 5 (Three native herbaceous species in the PEM):

Three native herbaceous species were observed in the emergent area including: soft-stem bulrush (Schoenoplectus tabernaemontani), swamp smartweed (Persicaria hydropiperoides), and Indian-hemp (Apocynum cannabinum).

240 Columbia Causeway 9 2018 Annual Monitoring Report Results for Performance Standard 6 (40% cover native plant species in the upland buffer):

Cover of native species in the upland buffer is estimated at 49% (CI80%= 39-59%). Total cover with non-native species included is estimated at 74% (CI80%= 66-81%).

Results for Performance Standard 7 (Three native plant species in the upland buffer):

More than three native plant species were observed in the upland buffer including: Pacific willow, inland saltgrass (Distichlis spicata), basin wildrye (Leymus cinereus), Photo 4 bluebunch wheatgrass (Pseudoroegneria spicata), snowberry Woody cover in the upland buffer (August 2018) (Symphoricarpos albus), sandbar willow, yellow rabbitbrush (Chrysothamnus viscidiflorus), blue wildrye (Elymus glaucus), meadow barley (Hordeum brachyantherum), Nootka rose (Rosa nutkana), and Indian-hemp. This exceeds the performance standard target.

240 Columbia Causeway 10 2018 Annual Monitoring Report Results for Performance Standard 8 (No Washington State-listed or county-listed Class A weeds):

None observed at the time of monitoring.

Results for Performance Standard 9 (Control of Benton County-designated Class B and C weeds):

None of the county-listed species observed at the time of monitoring.

Results for Performance Standard 10 (Less than 15% cover kochia, puncturevine, common reed, prickly Russian thistle, and Russian olive combined across the site):

Cover of common reed and Russian olive is qualitatively estimated at 10 percent across the site. Kochia and reed canarygrass (Phalaris arundinacea) were observed but both showed signs of recent and extensive control. No puncturevine or prickly Russian thistle observed.

What is planned for this site? Weed control will continue in 2019 as WSDOT requests site closeout from the Army Corps.

240 Columbia Causeway 11 2018 Annual Monitoring Report Appendix 1 – Planting Plan (from Davari 2006)

240 Columbia Causeway 12 2018 Annual Monitoring Report 240 Columbia Causeway 13 2018 Annual Monitoring Report 240 Columbia Causeway 14 2018 Annual Monitoring Report Appendix 2 – Photo Points The photographs below were taken from permanent photo-points on August 1, 2018 and document current site development.

240 Columbia Causeway 15 2018 Annual Monitoring Report

Photo Point 1a – East Unit Photo Point 1b – East Unit

Photo Point 2a – East Unit Photo Point 2b – East Unit

240 Columbia Causeway 16 2018 Annual Monitoring Report

Photo Point 3a – East Unit Photo Point 3b – East Unit

Photo Point 4a – West Unit Photo Point 4b – West Unit

240 Columbia Causeway 17 2018 Annual Monitoring Report

Photo Point 5a – West Unit Photo Point 5b – West Unit

Photo Point 6 – West Unit

240 Columbia Causeway 18 2018 Annual Monitoring Report

Driving Directions: From I-5, take SR 12 to the Tri-Cities area. From 182/12 West, take 240 south toward Kennewick. Exit at Columbia Park Trail and turn left at the end of the exit ramp to travel east on Columbia Park Trail. Go to the first intersection at Nevada Avenue and turn around. Just before the entrance ramp to SR 240 Northbound, hop the curb to the right and enter the bike trail. Follow the bike trail until you see the site on your right (a few hundred meters). There are a number of gates in the fence to access the site.

240 Columbia Causeway 19 2018 Annual Monitoring Report Appendix 3 – Data Tables

Table 1. Benton County Class B and Class C Noxious Weeds

Class B weeds: Class C weeds:

houndstongue (Cynoglossum officinale) Babysbreath (Gypsophila paniculata) diffuse knapweed (Centaurea diffusa) jointed goatgrass (Aegilops cylindrical) spotted knapweed (Centaurea stoebe) old-man-in-the-spring (Senecio vulgaris) yellow star-thistle (Centaurea solstitialis) paleyellow iris (Iris pseudacorus) Non-native knotweeds (Persicaria wallichii, Reynoutria codlins and cream (Epilobium hirsutum) japonica, R. bohemica, and R. sachalinensis) purple loosestrife (Lythrum salicaria) cereal rye (Secale cereal) yellow nutsedge (Cyperus esculentus) bull thistle (Cirsium vulgare) Rush skeletonweed (Chondrilla juncea) Canada thistle (Cirsium arvense) field sowthistle (Sonchus arvensis) poison hemlock (Conium maculatum)

Scotch thistle (Onopordum acanthium)

musk thistle (Carduus nutans)

Dalmatian toadflax (Linaria dalmatica)

butterfly bush (Buddleja davidii)

Eurasian watermilfoil (Myriophyllum spicatum)

240 Columbia Causeway 20 2018 Annual Monitoring Report Table 2. Sampling Methodology

PS 2 PS 2 East West PS 3 PS 4 PS 5 PS 6 PS 7 PS 8 PS 9 PS 10 Presence/ Presence/ Attribute Cover Cover Cover Number Number Cover Number absence absence Cover Burning bush, puncturevine, Target common population reed, prickly Native Native Native Native Native Native Native Class B Russian woody woody Herbaceous woody Herbaceous plant plant Class A and C thistle, and species species species species species species species weeds weeds Russian olive PSS/ PSS/ PSS/ Zone PFO PFO PEM PFO PEM Buffer Buffer Entire site Entire site Entire site Sample Line- Line- Point- Species Point- Species method intercept intercept intercept list Species list intercept list Qualitative Qualitative Qualitative SU length 15m 5m 5m 10m Points per SU 20 20 Total # of SU 19 14 8 19

240 Columbia Causeway 21 2018 Annual Monitoring Report Appendix 4 – Wetland Delineation

240 Columbia Causeway 22 2018 Annual Monitoring Report

WETLAND DELINEATION REPORT

SR 240 Causeway Mitigation Site

SR 240, I-182 to Columbia Center Interchange Construct Additional Lanes USACE Permit No. 200400043 Ecology WQC Order 1760

Benton County, Washington

Prepared by: Tatiana Dreisbach WSDOT Environmental Services Office Olympia, Washington

April 2017

Introduction

This report was prepared by the Washington State Department of Transportation (WSDOT) to describe the wetland boundary delineation for the SR 240 Causeway Mitigation Site. Field work was conducted by WSDOT wetland biologists Tatiana Dreisbach and Doug Littauer, on September 26 and 27, 2016. The delineation identifies 17.24 acres of wetland within the mitigation site boundaries, of which 15.67 occurs in intended wetland areas and the remaining 1.57 acres occurs in intended buffer areas. The site contains two distinct portions separated by SR 240 but hydrologically connected during spring inundation through a large culvert and wildlife crossing structure. When necessary to discuss the distinct portions separately in this report, they will hereinafter be referred to as SR 240 East and SR 240 West.

SR 240 East wetland was previously delineated in August 2010 and SR 240 West was delineated in August 2015. The purpose of the 2016 field work was to reevaluate the 2010 and 2015 wetland boundaries and document any wetland boundary modifications if necessary. Sample point data were recollected at SR 240 East. The 2016 delineation confirmed the wetland boundary has not changed on either site, from the prior delineations to 2016.

General Information for the SR 240 Causeway Mitigation Site Location: S24, T9N, R29E. Benton County. (Vicinity map, Figure 1) USACE Permit Number 200400043 Long./Lat. ID Number 1192477462437 Land Resource Region (LRR) B

Major Land Resource Area (MLRA) 7

Construction Date 2007 Monitoring Period 2009 - 2018 8 of 10 (in 2016) Year of Monitoring Area of Project Impact1 9.65 acres Location Type of Mitigation Required Acreage1 2016 Delineated Acreage West Unit Enhancement 1.30 0.97 East Unit Enhancement 4.30 3.60 East Unit Establishment 10.19 11.10

Wetland Totals 15.79 15.672 East Unit 50 foot regulatory wet buffer 50 feet along west edge 1.57

1 Project impact USACE Nationwide Permit 200400043 (USACE 2004), and required acreages from Final Wetland Mitigation Plan (WSDOT 2004). 2 Both SR 240 East and SR 240 West are contiguous with off-site wetlands. The above delineated totals represent WSDOT’s best information on the wetland mitigation site boundary.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 1

Location

Figure 1. Vicinity Map

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 2

Methods

Wetland boundaries within the SR 240 Causeway Mitigation Site were delineated using routine methods described in the:

• Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987), • Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0) (USACE 2008) Wetland boundaries were delineated based on on-site observations of hydrology, soils, and plant communities, in conjunction with background information.

A Global Positioning System (GPS) Trimble GeoXT mapping grade unit was used to: • navigate to the 2010 SR 240 East delineation boundary and the 2015 SR 240 West delineation boundary • record 2016 sampling point locations and • record 2016 wetland boundary amendments where necessary (Figure 1).

On SR 240 East, wetland mitigation types (Figure 2) were georeferenced by digitizing the mitigation site as-built plan (WSDOT 2008) in ArcGIS 10.3.1. The eastern boundary was established using ArcMap data provided by WSDOT Southcentral Region (SCR). The apparent source of this line was provided by the USACE to SCR and documents WSDOT’s easement on USACE property. Inherent in both GPS and georeferencing are minute errors, resulting in slight inaccuracies in both boundary line placement and acreage calculations. These tools represent the best available methods at the time of the study and report preparation.

On SR 240 East, the wetland delineated based on field observations of grading and mitigation plantings. The as-built (WSDOT, 2008) notes that the entire SR 240 West contains the one mitigation type of enhancement.

Wetland Delineation and Study Area

Study Area Wetlands described in this report were assessed only within the wetland mitigation site boundary (Figure 2). Both the SR 240 East and SR 240 West portions of the wetland are contiguous with off-site wetlands, which are not documented in this report.

Wetland Changes Since 2010 and 2015 The SR 240 Causeway mitigation site remains in similar condition as documented in the 2010 SR 240 East and 2015 SR 240 West delineations, with the exception that SR 240 East woody vegetation has had time to establish a more developed canopy structure, tree height, and overall vegetation cover. The wetland boundary and acreage remains unchanged on both the SR 240 East and SR 240 West sites. This is to be expected

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 3 given that the majority of both wetland areas are seasonally flooded and bounded by topographic features which influence the area that has potential to hold seasonal ponding.

Wetland Boundary Verification The 2016 delineation verification determined a total of 17.24 acres of wetland were present within the SR 240 Causeway Mitigation Site: 14.7 acres at SR 240 East in intended wetland areas, 1.57 in regulatory buffer areas, and 0.97 acre in intended wetland areas at SR 240 West. The wetland boundary and wetland area remain unchanged from conditions documented in 2010 SR 240 East and 2015 SR 240 West delineations. The wetland on both the portions of the site are contiguous with off-site wetlands.

Delineation data were collected at six sampling points; three each at SR 240 East and SR 240 West, and were recorded on wetland determination data forms (Appendix A). Paired wetland and upland sample points were used to define the wetland edge and were placed in locations documenting the wetland boundary.

Data recorded on wetland determination data forms characterize typical wetland and upland conditions observed on site. Vegetation, soils, and hydrology were examined in many additional sampling locations to determine the wetland boundary.

Precipitation The Regional Delineation Supplement Version 2.0 (USACE 2008) recommends using methods described in Chapter 19 in Engineering Field Handbook (NRCS 1997) to determine if precipitation occurring in the three full months prior to the site visit was normal, drier than normal, or wetter than normal. Actual rainfall is compared to the normal range of the 30-year average. When considering the three prior months for the 2016 field work as a whole, normal precipitation conditions were present prior to field work. Two of the three months prior to field work were within the normal range with the second prior month drier than normal (Appendix B-1). The 2015 SR 240 West delineation occurred during a period with drier than normal precipitation conditions characterizing the three month period prior to field work (Appendix B-3).

No precipitation was recorded in the ten days preceding both the 2016 and 2015 field work (Appendix B-2; Appendix B-4).

Growing Season The delineation occurred at the end of the growing season, however the following evidence of the growing season was observed at the time of the delineation: • Green vegetative portions of some herbaceous plants remained. • Some green leaves remained on many of the woody species.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 4

Figure 2. Delineation and Mitigation Types Map.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 5

SR 240 Causeway East Mitigation Site – Wetland Delineation Summary 17.24 acres (14.7 acres in intended wetland areas, 1.57 in

Total Delineated Wetland Area regulatory buffer areas) Wetland Determination Appendix A; Sampling Points Data Forms W1-SP1 and W1-SP3

Upland Determination Appendix A; Sampling Point Data Form W1-SP2

Tatiana Dreisbach, Delineators Doug Littauer

Delineation Date September 26 and 27, 2016

Trees – eastern cottonwood (Populus deltoids) Shrubs – eastern cottonwood, sandbar willow (Salix exigua) Vegetation Herbs – narrowleaf cattail (Typha angustifolia), soft-stem bulrush (Schoenoplectus tabernaemontani), reed canarygrass (Phalaris arundinacea) Soils examined to a depth of 16 inches exhibited hydric characteristics. Matrix colors of Soils 2.5Y 4/2 and 2.5Y 2.5/1 were observed. Redoximorphic concentrations and depletions were observed in some layers. Indicator Depleted Matrix (F3) met. Seasonal surface ponding, supported by a long duration high groundwater table driven by hyporheic flows associated with the Yakima River appears to be the main hydrologic regime. Direct observation of water was observed in PEM areas with some areas with Hydrology soils saturated to the surface with a water table around 10 inches below the surface. Several additional wetland hydrology indicators were observed in PSS areas including sediment deposits and surface soil cracks. Positive indicators of all three wetland criteria are present. Placement of boundary determined by vegetation and topographic break. Wetland vegetation stopped abruptly Rationale for and upland areas directly adjacent to wetland were dominated by bare ground or upland Delineation species. Distinct topographic break present in some areas. The wetland is contiguous with a larger wetland complex. The only true wetland/upland boundary is along the southwestern edge.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 6

SR 240 Causeway West Mitigation Site – Wetland Delineation Summary

Total Delineated Wetland Area 0.97 acres

Wetland Determination Appendix A; Sampling Points Data Forms W1-SP1 and W1-SP2

Upland Determination Appendix A; Sampling Points Data Form W1-SP3

Tatiana Dreisbach, Delineators Doug Littauer

Delineation Date September 26 and 27, 2016

Trees – none Shrubs – willows (Salix spp.), white poplar (Populus alba) Vegetation Herbs –broadleaf cattail (Typha latifolia), narrowleaf cattail, reed canarygrass, barnyardgrass (Echinochloa crus-galli), meadow foxtail (Alopecurus pratensis), jointleaf rush (Juncus articulatus), curly dock (Rumex crispus) Soils examined to a depth of 6 inches exhibited hydric characteristics. Matrix colors of Soils 2.5Y 4/2 were observed. Redoximorphic concentrations were also observed. Indicator Depleted Matrix (F3) met. Seasonal surface ponding with saturation at the fringe appears to be the main hydrologic regime with sources of surface water backwatering into the wetland ditch from the Yakima River during spring flows. A high groundwater table driven by hyporheic flows associated with the Yakima River contribute to the hydrologic regime of Hydrology this wetland. Direct observation of water was not observed because the delineation occurred during the dry season, however several wetland hydrology indicators were observed including sediment deposits and surface soil cracks. In addition, adventitious roots were observed on some willows (thought this is not an indicator for Arid West). Old beaver chewed debris was also observed in some locations. Positive indicators of all three wetland criteria are present. Placement of boundary determined by vegetation, soils, and topographic break. Wetland vegetation stopped Rationale for abruptly and upland areas directly adjacent to wetland were dominated by bare ground Delineation or upland species. A similar correlation was observed with hydric and non-hydric soils. Distinct topographic break present throughout the majority of the wetland. The wetland is contiguous with off-site wetland areas extending to the southwest.

Limitations

This wetland delineation report documents the investigation, best professional judgment and conclusions of WSDOT based on the site conditions encountered at the time of this study. The wetland delineation was performed in compliance with accepted standards for professional wetland biologists and applicable federal, state, and local ordinances. It is correct and complete to the best of our knowledge. It should be considered a preliminary jurisdictional determination of wetlands and other waters until it has been reviewed and approved in writing by the appropriate jurisdictional authorities.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 7

References 1. Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Vicksburg (MS): US Army Engineer Waterways Experiment Station. Technical Report Y- 87-1. Available from: http://el.erdc.usace.army.mil/elpubs/pdf/wlman87.pdf 2. [NRCS] Natural Resource Conservation Service. 1997. Hydrology Tools for wetland determination. Chapter 19 in Engineering Field Handbook. Fort Worth (TX): US. Department of Agriculture, NRCS. http://www.wsdot.wa.gov/NR/rdonlyres/0685A8C8- 0512-4568-BE7F-6FF6D75C15ED/0/WetDelinCh19.pdf 3. [NRCS] Natural Resources Conservation Service [Internet]. 2016. Field Office Technical Guide. US Department of Agriculture. Climate Data for Benton County, Station Richland, Washington 457015. [cited 2016 Oct 4]. Available at: http://agacis.rcc- acis.org/53005/wets 4. [NRCS] Natural Resource Conservation Service [Internet]. 2016. Web Soil Survey for Benton County, Washington. US Department of Agriculture. [cited 2016 Oct 4]. Available at: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx 5. US Army Corps of Engineers. 2014. National Wetland Plant List, version 3.2 [Internet]. US Army Corps of Engineers, Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory, Hanover, NH. Available at: http://rsgisias.crrel.usace.army.mil/NWPL/ 6. [USACE] US Army Corps of Engineers. 2004. Department of the Army Permit Number 200400043. 7. [USACE] US Army Corps of Engineers. 2008. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0), ed. Wakeley JS, Lichvar RW, Noble CV, editors. Vicksburg (MS): US Army Engineer Research and Development Center. ERDC/EL TR-08-28. Available at: http://www.usace.army.mil/Portals/2/docs/civilworks/regulatory/reg_supp/trel08-28.pdf 8. [WSDOT] Washington State Department of Transportation. 2004. SR 240, I-182 to Columbia Center Interchange Construct Additional Lanes Final Mitigation Plan. Union Gap (WA): Washington State Department of Transportation, South Central Region. 9. [WSDOT] Washington State Department of Transportation. 2008. Southcentral Region Mitigation Site As Built Report. SR 240 I-182 to Columbia Center Interchange. Union Gap (WA): Washington State Department of Transportation, South Central Region.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report 8

Appendix A —Wetland Determination Data Forms

Wetland Delineation Data Forms for:

SR 240 Causeway West W1-SP1 W1-SP2 W1-SP3

SR 240 Causeway East W1-SP1 W1-SP2 W1-SP3

Wetland polygons, sampling point locations, and wetland names shown in Figure 2.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report WETLAND DETERMINATION DATA FORM - Arid West Region

Project/Site: 240 Columbia Causeway West City/County: Richland/Benton Sampling Date: 04-Aug-15

Applicant/Owner: WSDOT State: WA Sampling Point: w1-sp1 Investigator(s): Tatiana Dreisbach Section, Township, Range: S 24 T 9N R 29E Landform (hillslope, terrace, etc.): constructed wetland ditch Local relief (concave, convex, none): concave Slope: 5.0 % / 2.9 °

Subregion (LRR): LRR B Lat.:46.249 Long.: -119.255 Datum: NAD83HARN

Soil Map Unit Name: Pasco silt loam, 0 to 2 percent slopes NWI classification: PEM Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)

Are Vegetation , Soil , or Hydrology significantly disturbed? Are "Normal Circumstances" present? Yes No

Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)

Summary of Findings - Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No Is the Sampled Area Hydric Soil Present? Yes No within a Wetland? Yes No Wetland Hydrology Present? Yes No Remarks: All three factors problematic. Vegetation is problematic due to weed mat, though emergent vegetation establishing on top of it. Soils highly manipulated by construction of roadway project and mitigation site. Hydrology assessment in the dry season during preiod with bleow normal

VEGETATION - Use scientific names of plants. Dominant Species? Absolute Rel.Strat. Indicator Dominance Test worksheet: Tree Stratum (Plot size: 10 x 20 feet ) % Cover Cover Status Number of Dominant Species 1. 0.0% That are OBL, FACW, or FAC: 6 (A) 2. 0.0% Total Number of Dominant 3. 0.0% Species Across All Strata: 7 (B) 4. 0.0% Percent of dominant Species 0 = Total Cover That Are OBL, FACW, or FAC: 85.7% (A/B) Sapling/Shrub Stratum (Plot size: 10 x 10 feet ) 1. 0.0% Prevalence Index worksheet: 2. 0.0% Total % Cover of: Multiply by 3. 0.0% OBL species 32 x 1 = 32 4. 0.0% FACW species 10 x 2 = 20 5. 0.0% FAC species 5 x 3 = 15 0 = Total Cover FACU species 0 x 4 = 0 Herb Stratum (Plot size: 5 x 5 feet ) UPL species 0 x 5 = 0 1. Typha angustifolia 20 38.5% OBL Column Totals: 47 (A) 67 (B) 2. Typha latifolia 5 9.6% OBL 3. Phalaris arundinacea 5 9.6% FACW Prevalence Index = B/A = 1.426 4. Rumex crispus 5 9.6% FAC Hydrophytic Vegetation Indicators: 5. Echinochloa crus-galli 5 9.6% FACW Dominance Test is > 50% 1 6. Alopecurus geniculatus 5 9.6% OBL Prevalence Index is ≤3.0 Rorippa spp. 5 9.6% 7. Morphological Adaptations 1 (Provide supporting 8. Juncus articulatus 2 3.8% OBL data in Remarks or on a separate sheet) 0 0.0% 1 9. Problematic Hydrophytic Vegetation 1 (Explain) 10. 0 0.0% 11. 0 0.0% 1 Indicators of hydric soil and wetland hydrology must 52 = Total Cover be present, unless disturbed or problematic. Woody Vine Stratum (Plot size: 5 x 5 feet ) 1. 0.0% 2. 0.0% Hydrophytic Vegetation 0 = Total Cover Present? Yes No % Bare Ground in Herb Stratum: 48 % Cover of Biotic Crust 0 Remarks:

*Indicator suffix = National status or professional decision assigned because Regional status not defined by FWS. US Army Corps of Engineers Arid West - Version 2.0 Soil Sampling Point: w1-sp1 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type 1 Loc² Texture Remarks concentration is prominent 0-6 2.5Y 4/2 90 7.5YR 4/4 10 C M Silt Loam

1 Type: C=Concentration. D=Depletion. RM=Reduced Matrix, CS=Covered or Coated Sand Grains ²Location: PL=Pore Lining. M=Matrix

Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils:3 Histosol (A1) Sandy Redox (S5) 1 cm Muck (A9) (LRR C) Histic Epipedon (A2) Stripped Matrix (S6) 2 cm Muck (A10) (LRR B) Black Histic (A3) Loamy Mucky Mineral (F1) Reduced Vertic (F18) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Red Parent Material (TF2) Stratified Layers (A5) (LRR C) Depleted Matrix (F3) Other (Explain in Remarks) 1 cm Muck (A9) (LRR D) Redox Dark Surface (F6) Depleted Below Dark Surface (A11) Depleted Dark Surface (F7) Thick Dark Surface (A12) Redox depressions (F8) 3 Sandy Muck Mineral (S1) Indicators of hydrophytic vegetation and Vernal Pools (F9) wetland hydrology must be present. Sandy Gleyed Matrix (S4) Restrictive Layer (if present): Type: Hydric Soil Present? Depth (inches): Yes No Remarks: Soils very dry. Only excavated down enough to meet an indicator.

Hydrology

Wetland Hydrology Indicators: Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Salt Crust (B11) Water Marks (B1) (Riverine) High Water Table (A2) Biotic Crust (B12) Sediment Deposits (B2) (Riverine) Saturation (A3) Aquatic Invertebrates (B13) Drift Deposits (B3) Riverine) Water Marks (B1) (Nonriverine) Hydrogen Sulfide Odor (C1) Drainage Patterns (B10) Sediment Deposits (B2) (Nonriverine) Oxidized Rhizospheres along Living Roots (C3) Dry Season Water Table (C2) Drift deposits (B3) (Noneriverine) Presence of Reduced Iron (C4) Crayfish Burrows (C8) Surface Soil Cracks (B6) Recent Iron Reduction in Plowed Soils (C6) Saturation Visible on Aerial Imagery (C9) Inundation Visible on Aerial Imagery (B7) Thin Muck Surface (C7) Shallow Aquitard (D3) Water-Stained Leaves (B9) Other (Explain in Remarks) FAC-neutral Test (D5)

Field Observations: Surface Water Present? Yes No Depth (inches):

Water Table Present? Yes No Depth (inches): Saturation Present? Wetland Hydrology Present? Yes No Yes No Depth (inches): (includes capillary fringe) Describe Recorded Data (stream gauge, monitor well, aerial photos, previous inspections), if available:

Remarks: Hydrology indicators met despite site visit in dry part of the year. Geomorphic position also indicates seasonal ponding is present in the area. Old beaver chewed wood debris also observed in the wetland.

US Army Corps of Engineers Arid West - Version 2.0 WETLAND DETERMINATION DATA FORM - Arid West Region

Project/Site: 240 Columbia Causeway West City/County: Richland/Benton Sampling Date: 04-Aug-15

Applicant/Owner: WSDOT State: WA Sampling Point: w1-sp2 Investigator(s): Tatiana Dreisbach Section, Township, Range: S 24 T 9N R 29E Landform (hillslope, terrace, etc.): wetland ditch Local relief (concave, convex, none): concave Slope: 5.0 % / 2.9 °

Subregion (LRR): LRR B Lat.:46.249 Long.: -119.255 Datum: NAD83HARN

Soil Map Unit Name: Pasco silt loam, 0 to 2 percent slopes NWI classification: PSS Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)

Are Vegetation , Soil , or Hydrology significantly disturbed? Are "Normal Circumstances" present? Yes No

Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)

Summary of Findings - Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No Is the Sampled Area Hydric Soil Present? Yes No within a Wetland? Yes No Wetland Hydrology Present? Yes No Remarks: All three factors problematic. Weed mat inhibits herbaceous growth though some herbs are esrablishing above weed mat. Soils highly manipulated by construction of roadway project and then mitigation site. Hydrology assessment in the dry season during preiod with bleow normal precipitation.

VEGETATION - Use scientific names of plants. Dominant Species? Absolute Rel.Strat. Indicator Dominance Test worksheet: Tree Stratum (Plot size: 20 x 20 feet ) % Cover Cover Status Number of Dominant Species 1. 0.0% That are OBL, FACW, or FAC: 3 (A) 2. 0.0% Total Number of Dominant 3. 0.0% Species Across All Strata: 3 (B) 4. 0.0% Percent of dominant Species 0 = Total Cover That Are OBL, FACW, or FAC: 100.0% (A/B) Sapling/Shrub Stratum (Plot size: 20 x 20 feet ) 1. Salix spp. 70 87.5% FAC Prevalence Index worksheet: 2. Populus alba 10 12.5% UPL Total % Cover of: Multiply by 3. 0 0.0% OBL species 35 x 1 = 35 4. 0 0.0% FACW species 10 x 2 = 20 5. 0 0.0% FAC species 70 x 3 = 210 80 = Total Cover FACU species 0 x 4 = 0 Herb Stratum (Plot size: 5 x 5 feet ) UPL species 10 x 5 = 50 1. Typha angustifolia 30 66.7% OBL Column Totals: 125 (A) 315 (B) 2. Phalaris arundinacea 10 22.2% FACW 3. Schoenoplectus acutus 5 11.1% OBL Prevalence Index = B/A = 2.520 4. 0 0.0% Hydrophytic Vegetation Indicators: 5. 0 0.0% Dominance Test is > 50% 1 6. 0 0.0% Prevalence Index is ≤3.0 0 0.0% 7. Morphological Adaptations 1 (Provide supporting 8. 0 0.0% data in Remarks or on a separate sheet) 0 0.0% 1 9. Problematic Hydrophytic Vegetation 1 (Explain) 10. 0 0.0% 11. 0 0.0% 1 Indicators of hydric soil and wetland hydrology must 45 = Total Cover be present, unless disturbed or problematic. Woody Vine Stratum (Plot size: 5 x 5 feet ) 1. 0.0% 2. 0.0% Hydrophytic Vegetation 0 = Total Cover Present? Yes No % Bare Ground in Herb Stratum: 55 % Cover of Biotic Crust 0 Remarks: Salix species assumed to be FAC or wetter because common species in our region are all FAC or wetter and it is growing in an area with wetland hydrology indicators present.

*Indicator suffix = National status or professional decision assigned because Regional status not defined by FWS. US Army Corps of Engineers Arid West - Version 2.0 Soil Sampling Point: w1-sp2 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type 1 Loc² Texture Remarks concentration is prominent 0-6 2.5Y 4/2 95 7.5YR 4/4 5 C M Silt Loam

1 Type: C=Concentration. D=Depletion. RM=Reduced Matrix, CS=Covered or Coated Sand Grains ²Location: PL=Pore Lining. M=Matrix

Hydrology

Field Observations: Surface Water Present? Yes No Depth (inches):

US Army Corps of Engineers Arid West - Version 2.0 WETLAND DETERMINATION DATA FORM - Arid West Region

Project/Site: 240 Columbia Causeway West City/County: Richland/Benton Sampling Date: 04-Aug-15

Applicant/Owner: WSDOT State: WA Sampling Point: w1-sp3 Investigator(s): Tatiana Dreisbach Section, Township, Range: S 24 T 9N R 29E Landform (hillslope, terrace, etc.): wetland ditch Local relief (concave, convex, none): concave Slope: 5.0 % / 2.9 °

Subregion (LRR): LRR B Lat.:46.25 Long.: -119.255 Datum: NAD83HARN

Soil Map Unit Name: Pasco silt loam, 0 to 2 percent slopes NWI classification: Upland Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)

Are Vegetation , Soil , or Hydrology significantly disturbed? Are "Normal Circumstances" present? Yes No

Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)

Summary of Findings - Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No Is the Sampled Area Hydric Soil Present? Yes No within a Wetland? Yes No Wetland Hydrology Present? Yes No Remarks: soils and hydrology factors problematic. Soils highly manipulated by construction of roadway project and then mitigation site. Hydrology assessment in the dry season during preiod with bleow normal precipitation.

VEGETATION - Use scientific names of plants. Dominant Species? Absolute Rel.Strat. Indicator Dominance Test worksheet: Tree Stratum (Plot size: 10 x 20 feet ) % Cover Cover Status Number of Dominant Species 1. 0.0% That are OBL, FACW, or FAC: 1 (A) 2. 0.0% Total Number of Dominant 3. 0.0% Species Across All Strata: 2 (B) 4. 0.0% Percent of dominant Species 0 = Total Cover That Are OBL, FACW, or FAC: 50.0% (A/B) Sapling/Shrub Stratum (Plot size: 20 x 20 feet ) 1. 0.0% Prevalence Index worksheet: 2. 0.0% Total % Cover of: Multiply by 3. 0.0% OBL species 0 x 1 = 0 4. 0.0% FACW species 0 x 2 = 0 5. 0.0% FAC species 20 x 3 = 60 0 = Total Cover FACU species 0 x 4 = 0 Herb Stratum (Plot size: 5 x 5 feet ) UPL species 20 x 5 = 100 1. Bromus tectorum 20 50.0% UPL Column Totals: 40 (A) 160 (B) 2. Bassia scoparia 20 50.0% FAC 3. 0 0.0% Prevalence Index = B/A = 4.000 4. 0 0.0% Hydrophytic Vegetation Indicators: 5. 0 0.0% Dominance Test is > 50% 1 6. 0 0.0% Prevalence Index is ≤3.0 0 0.0% 7. Morphological Adaptations 1 (Provide supporting 8. 0 0.0% data in Remarks or on a separate sheet) 0 0.0% 1 9. Problematic Hydrophytic Vegetation 1 (Explain) 10. 0 0.0% 11. 0 0.0% 1 Indicators of hydric soil and wetland hydrology must 40 = Total Cover be present, unless disturbed or problematic. Woody Vine Stratum (Plot size: 5 x 5 feet ) 1. 0.0% 2. 0.0% Hydrophytic Vegetation 0 = Total Cover Present? Yes No % Bare Ground in Herb Stratum: 60 % Cover of Biotic Crust 0 Remarks:

*Indicator suffix = National status or professional decision assigned because Regional status not defined by FWS. US Army Corps of Engineers Arid West - Version 2.0 Soil Sampling Point: w1-sp3 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type 1 Loc² Texture Remarks Loamy Sand upland on old road prism. 0-3 2.5YR 4/2 100 compaction and cobbles

1 Type: C=Concentration. D=Depletion. RM=Reduced Matrix, CS=Covered or Coated Sand Grains ²Location: PL=Pore Lining. M=Matrix

Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils:3 Histosol (A1) Sandy Redox (S5) 1 cm Muck (A9) (LRR C) Histic Epipedon (A2) Stripped Matrix (S6) 2 cm Muck (A10) (LRR B) Black Histic (A3) Loamy Mucky Mineral (F1) Reduced Vertic (F18) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Red Parent Material (TF2) Stratified Layers (A5) (LRR C) Depleted Matrix (F3) Other (Explain in Remarks) 1 cm Muck (A9) (LRR D) Redox Dark Surface (F6) Depleted Below Dark Surface (A11) Depleted Dark Surface (F7) Thick Dark Surface (A12) Redox depressions (F8) 3 Sandy Muck Mineral (S1) Indicators of hydrophytic vegetation and Vernal Pools (F9) wetland hydrology must be present. Sandy Gleyed Matrix (S4) Restrictive Layer (if present): Type: cobbles of road bed Hydric Soil Present? Yes No Depth (inches): 3 Remarks: On old road bed. Sands and cobbles placed by construction and from erosion from above from the road prism. Pit could not be excavated below three inches.

Hydrology

Field Observations: Surface Water Present? Yes No Depth (inches):

Remarks:

US Army Corps of Engineers Arid West - Version 2.0 WETLAND DETERMINATION DATA FORM - Arid West Region

Project/Site: 240 Columbia Causeway East City/County: Richland/Benton Sampling Date: 26-Sep-16

Applicant/Owner: WSDOT State: WA Sampling Point: w1-sp1 Investigator(s): Tatiana Dreisbach, Doug Littauer Section, Township, Range: S 24 T 9N R 29E Landform (hillslope, terrace, etc.): river flat Local relief (concave, convex, none): concave Slope: 5.0 % / 2.9 °

Subregion (LRR): LRR B Lat.: Long.: Datum: NAD83HARN

Soil Map Unit Name: Pasco silt loam, 0 to 2 percent slopes NWI classification: PSS Are climatic/hydrologic conditions on the site typical for this time of year? YesYesYes NoNoNo (If no, explain in Remarks.)

Are Vegetation , Soil , or Hydrology significantly disturbed? Are "Normal Circumstances" present? YesYesYes NoNoNo

Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)

Summary of Findings - Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? YesYesYes NoNoNo Is the Sampled Area Hydric Soil Present? YesYesYes NoNoNo within a Wetland? YesYesYes NoNoNo Wetland Hydrology Present? YesYesYes NoNoNo Remarks:

1. Populus deltoides 20 66.7% FAC Prevalence Index worksheet: 2. Salix exigua 10 33.3% FACW Total % Cover of: Multiply by 3. 0.0% OBL species 15 x 1 = 15 4. 0.0% FACW species 27 x 2 =x = 54 5. 0.0% FAC species 25 x 3 =x = 75 30 = Total Cover FACU species 19 x 4 = 76 Herb Stratum (Plot size: 5 x 5 feet ) UPL species 0 x 5 = 0 1. Juncus articulatus 15 26.8% OBL Column Totals: 86 (A)(A)(A) 220 (B)(B)(B) 2. Phalaris arundinacea 15 26.8% FACW 3. Conyza canadensis 10 17.9% FACU Prevalence Index = B/A = 2.558

4. Hordeum jubatum 5 8.9% FAC Hydrophytic Vegetation Indicators: 5. Bromus arvensis 5 8.9% FACU Dominance Test is > 50% 1 6. Carex unilateralis 2 3.6% FACW Prevalence Index is ≤3.0 7. Lactuca serriola 2 3.6% FACU Morphological Adaptations 1 (Provide supporting 8. Digitaria sanguinalis 2 3.6% FACU data in Remarks or on a separate sheet) 9. 0 0.0% 1 Problematic Hydrophytic Vegetation 1 (Explain) 10. 0 0.0% 11. 0 0.0% 1 Indicators of hydric soil and wetland hydrology must 56 = Total Cover be present, unless disturbed or problematic. Woody Vine Stratum (Plot size: 5 x 5 feet ) 1. 0.0% 2. 0.0% Hydrophytic Vegetation 0 = Total Cover Present? YesYesYes NoNoNo % Bare Ground in Herb Stratum: 44 % Cover of Biotic Crust 0 Remarks:

*Indicator suffix = National status or professional decision assigned because Regional status not defined by FWS. US Army Corps of Engineers Arid West - Version 2.0 Soil Sampling Point: w1-sp1 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type 1 Loc² Texture Remarks concentration is distinct 0-7 2.5Y 4/2 88 7.5YR 3/3 7% C M Sandy Loam concentration is prominent 7.5YR 4/6 5% C M/PL

7-16 2.5Y 4/2 79 5Y 4/1 15% D M Sandy Loam concentration is prominent 7.5YR 4/6 5% C M concentration is prominent 7.5YR 5/8 1% C M

1 Type: C=Concentration. D=Depletion. RM=Reduced Matrix, CS=Covered or Coated Sand Grains ²Location: PL=Pore Lining. M=Matrix

Hydrology

Field Observations: Surface Water Present? YesYesYes NoNoNo Depth (inches):

Water Table Present? YesYesYes NoNoNo Depth (inches): Saturation Present? Wetland Hydrology Present? YesYesYes NoNoNo Depth (inches): (includes capillary fringe) YesYesYes NoNoNo Describe Recorded Data (stream gauge, monitor well, aerial photos, previous inspections), if available:

Remarks: Soils moist from 1-16 inches.

US Army Corps of Engineers Arid West - Version 2.0 WETLAND DETERMINATION DATA FORM - Arid West Region

Project/Site: 240 Columbia Causeway East City/County: Richland/Benton Sampling Date: 26-Sep-16

Applicant/Owner: WSDOT State: WA Sampling Point: w1-sp2 Investigator(s): Tatiana Dreisbach, Doug Littauer Section, Township, Range: S 24 T 9N R 29E Landform (hillslope, terrace, etc.): toeslope of road prism Local relief (concave, convex, none): concave Slope: 5.0 % / 2.9 °

Subregion (LRR): LRR B Lat.: Long.: Datum: NAD83HARN

Soil Map Unit Name: Pasco silt loam, 0 to 2 percent slopes NWI classification: Upland Are climatic/hydrologic conditions on the site typical for this time of year? YesYesYes NoNoNo (If no, explain in Remarks.)

Are Vegetation , Soil , or Hydrology significantly disturbed? Are "Normal Circumstances" present? YesYesYes NoNoNo

Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)

Summary of Findings - Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? YesYesYes NoNoNo Is the Sampled Area Hydric Soil Present? YesYesYes NoNoNo within a Wetland? YesYesYes NoNoNo Wetland Hydrology Present? YesYesYes NoNoNo Remarks:

1. Populus deltoides 20 100.0% FAC Prevalence Index worksheet: 2. 0.0% Total % Cover of: Multiply by 3. 0 0.0% OBL species 0 x 1 = 0 4. 0 0.0% FACW species 0 x 2 =x = 0 5. 0 0.0% FAC species 40 x 3 =x = 120 20 = Total Cover FACU species 7 x 4 = 28 Herb Stratum (Plot size: 10 x 10 feet ) UPL species 15 x 5 = 75 1. Bromus tectorum 10 23.8% UPL Column Totals: 62 (A)(A)(A) 223 (B)(B)(B) 2. Elymus repens 10 23.8% FAC 3. Leymus cinereus 10 23.8% FAC Prevalence Index = B/A = 3.597

4. Bromus arvensis 5 11.9% FACU Hydrophytic Vegetation Indicators: 5. Agropyron cristatum 5 11.9% UPL Dominance Test is > 50% 1 6. Salsola tragus 2 4.8% FACU Prevalence Index is ≤3.0 7. 0 0.0% Morphological Adaptations 1 (Provide supporting 8. 0 0.0% data in Remarks or on a separate sheet) 9. 0 0.0% 1 Problematic Hydrophytic Vegetation 1 (Explain) 10. 0 0.0% 11. 0 0.0% 1 Indicators of hydric soil and wetland hydrology must 42 = Total Cover be present, unless disturbed or problematic. Woody Vine Stratum (Plot size: 5 x 5 feet ) 1. 0.0% 2. 0.0% Hydrophytic Vegetation 0 = Total Cover Present? YesYesYes NoNoNo % Bare Ground in Herb Stratum: 58 % Cover of Biotic Crust 0 Remarks:

*Indicator suffix = National status or professional decision assigned because Regional status not defined by FWS. US Army Corps of Engineers Arid West - Version 2.0 Soil Sampling Point: w1-sp2 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type 1 Loc² Texture Remarks 0-18 2.5Y 5/2 95 2.5Y 8/2 5 D M Silt Loam

1 Type: C=Concentration. D=Depletion. RM=Reduced Matrix, CS=Covered or Coated Sand Grains ²Location: PL=Pore Lining. M=Matrix

Hydrology

Field Observations: Surface Water Present? YesYesYes NoNoNo Depth (inches):

US Army Corps of Engineers Arid West - Version 2.0 WETLAND DETERMINATION DATA FORM - Arid West Region

Project/Site: 240 Columbia Causeway East City/County: Richland/Benton Sampling Date: 26-Sep-16

Applicant/Owner: WSDOT State: WA Sampling Point: w1-sp3 Investigator(s): Tatiana Dreisbach, Doug Littauer Section, Township, Range: S 24 T 9N R 29E Landform (hillslope, terrace, etc.): river flat Local relief (concave, convex, none): concave Slope: 5.0 % / 2.9 °

Subregion (LRR): LRR B Lat.: Long.: Datum: NAD83HARN

Soil Map Unit Name: Pasco silt loam, 0 to 2 percent slopes NWI classification: PEM Are climatic/hydrologic conditions on the site typical for this time of year? YesYesYes NoNoNo (If no, explain in Remarks.)

Are Vegetation , Soil , or Hydrology significantly disturbed? Are "Normal Circumstances" present? YesYesYes NoNoNo

Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)

Summary of Findings - Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? YesYesYes NoNoNo Is the Sampled Area Hydric Soil Present? YesYesYes NoNoNo within a Wetland? YesYesYes NoNoNo Wetland Hydrology Present? YesYesYes NoNoNo Remarks:

1. 0.0% Prevalence Index worksheet: 2. 0.0% Total % Cover of: Multiply by 3. 0.0% OBL species 64 x 1 = 64 4. 0.0% FACW species 5 x 2 =x = 10 5. 0.0% FAC species 0 x 3 =x = 0 0 = Total Cover FACU species 0 x 4 = 0 Herb Stratum (Plot size: 10x 1 feet ) UPL species 0 x 5 = 0 1. Typha angustifolia 60 87.0% OBL Column Totals: 69 (A)(A)(A) 74 (B)(B)(B) 2. Phragmites australis 5 7.2% FACW 3. Schoenoplectus tabernaemontani 2 2.9% OBL Prevalence Index = B/A = 1.072

4. Lythrum salicaria 2 2.9% OBL Hydrophytic Vegetation Indicators: 5. 0 0.0% Dominance Test is > 50% 1 6. 0 0.0% Prevalence Index is ≤3.0 7. 0 0.0% Morphological Adaptations 1 (Provide supporting 8. 0 0.0% data in Remarks or on a separate sheet) 9. 0 0.0% 1 Problematic Hydrophytic Vegetation 1 (Explain) 10. 0 0.0% 11. 0 0.0% 1 Indicators of hydric soil and wetland hydrology must 69 = Total Cover be present, unless disturbed or problematic. Woody Vine Stratum (Plot size: 5 x 5 feet ) 1. 0.0% 2. 0.0% Hydrophytic Vegetation 0 = Total Cover Present? YesYesYes NoNoNo % Bare Ground in Herb Stratum: 31 % Cover of Biotic Crust 0 Remarks:

*Indicator suffix = National status or professional decision assigned because Regional status not defined by FWS. US Army Corps of Engineers Arid West - Version 2.0 Soil Sampling Point: w1-sp3 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type 1 Loc² Texture Remarks high OM and living roots 0-5 2.5Y 2.5/1 100 Silt Loam 5-16 5Y 4/2 85% 5Y 4/1 10% D M Silty Clay Loam concentration is prominent 10YR 4/6 5% C M/PL

1 Type: C=Concentration. D=Depletion. RM=Reduced Matrix, CS=Covered or Coated Sand Grains ²Location: PL=Pore Lining. M=Matrix

Hydrology

Field Observations: Surface Water Present? YesYesYes NoNoNo Depth (inches):

Water Table Present? YesYesYes NoNoNo Depth (inches): 10 Saturation Present? Wetland Hydrology Present? YesYesYes NoNoNo Depth (inches): 0 (includes capillary fringe) YesYesYes NoNoNo Describe Recorded Data (stream gauge, monitor well, aerial photos, previous inspections), if available:

Remarks:

US Army Corps of Engineers Arid West - Version 2.0 Appendix B — Precipitation Data Appendix B-1 and B-2 inform field observations made on September 26 and 27, 2016. This work includes wetland boundary verification and collection of new sample point data for SR 240 Causeway East. Normal precipitation conditions preceded the 2016 field visit to confirm the wetland boundary at both SR 240 Causeway East and West.

Appendix B-3 and B-4 provide supporting information for the August 3, 2015 delineation and associated sample point data. Drier than normal precipitation conditions preceded the 2015 field visit to SR 240 Causeway West

Appendix B-1. Comparison of Observed and Normal Precipitation for the September 2016 field work (NRCS 1997)

Monthly precipitation data for Richland, Washington.

Long-term rainfall recordsa 3 yrs. in 3 yrs. in Condition Month Product of Rain Condition Month 10 less Average 10 more dry, wet, weight previous two falla Value than than normalb value columns 1st prior month Sept 0.06 0.34 0.41 0.26 N 2 3 6 2nd prior month Aug 0.03 0.30 0.36 0.00 D 1 2 2 3rd prior month July 0.06 0.25 0.30 0.22 N 2 1 2 Sum 10

aNRCS 2016 bConditions are considered normal if they fall within the low and high range around the average.

Note: If sum is Condition value: 6 - 9 then prior period has been drier than normal Dry (D) =1 10 - 14 then period has been normal Normal (N) =2 15 - 18 then period has been wetter than normal Wet (W) =3

Conclusions: Normal precipitation conditions were present prior to the September 2016 field visit.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report Appendix B-2. Daily Precipitation 10 days preceding September 2016 field work

Daily precipitation data for Richland, Washington.

Date Daily Precipitation (2016) (inches)a Sept 25 0.00 Sept 24 0.00 Sept 23 0.00 Sept 22 0.00 Sept 21 0.00 Sept 20 0.00 Sept 19 0.00 Sept 18 0.00 Sept 17 0.00 Sept 16 0.00

Sum 0.00

a NRCS 2016

Conclusions: No precipitation was recorded in the ten days preceding field work.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report Appendix B-3. Comparison of Observed and Normal Precipitation for the August 2015 field work (NRCS 1997)

Monthly precipitation data for Richland, Washington.

Long-term rainfall recordsa 3 yrs. in 3 yrs. in Condition Month Product of Rain Condition Month 10 less Average 10 more dry, wet, weight previous two falla Value than than normalb value columns 1st prior month July 0.06 0.25 0.30 0.02 D 1 3 3 2nd prior month June 0.18 0.41 0.51 0.00 D 1 2 2 3rd prior month May 0.30 0.61 0.75 1.21 W 3 1 3 Sum 8

aNRCS 2016 bConditions are considered normal if they fall within the low and high range around the average.

Conclusions: Drier than normal precipitation conditions were present prior to the field visit.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report Appendix B-4. Daily Precipitation 10 days preceding August 2015 field work

Daily precipitation data for Richland, Washington.

Date Daily Precipitation (2015) (inches)a Aug 2 0.00 Aug 1 0.00 July 31 0.00 July 30 0.00 July 31 0.00 July 31 0.00 July 31 0.00 July 31 0.00 July 31 0.00 July 31 0.00

Sum 0.00

a NRCS 2016

Conclusions: No precipitation was recorded in the ten days preceding field work.

SR 240 Causeway Mitigation Site April 2017 Wetland Delineation Report Literature Cited

1. Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Vicksburg (MS): US Army Engineer Waterways Experiment Station. Technical Report Y-87-1. Available at: http://www.swl.usace.army.mil/Portals/50/docs/regulatory/wlman87.pdf

2. Davari, M., Washington State Department of Transportation (WSDOT). 2006. SR 240 I-182 to Columbia Center Interchange As-built Report. South Central Region, Richland, WA.

3. [USACE] US Army Corps of Engineers. 2004. Department of the Army Permit Number 2004-00043.

4. [USACE] US Army Corps of Engineers. 2008. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0), Wakeley JS, Lichvar RW, Noble CV, editors. Vicksburg (MS): US Army Engineer Research and Development Center. ERDC/EL TR-08-28. Available at: https://www.usace.army.mil/Missions/Civil-Works/Regulatory- Program-and-Permits/reg_supp/

5. [WSDOT] Washington State Department of Transportation. 2004. SR 240, I-182 to Columbia Center Interchange Construct Additional Lanes Final Mitigation Plan. Seattle (WA): Washington State Department of Transportation South Central Region, Yakima, WA. And 2008 and 2009 addendums. And 2011 Performance Standard addendum.

6. [WSDOT] Washington State Department of Transportation. 2008. WSDOT Wetland Mitigation Site Monitoring Methods. http://www.wsdot.wa.gov/NR/rdonlyres/C211AB59-D5A2-4AA2-8A76-3D9A77E01203/0/MethodsWhitePaper052004.pdf

240 Columbia Causeway 23 2018 Annual Monitoring Report