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Ex16_Critical_Areas_Designation_and_Mitigation_Plan
Beaver Creek Environmental Services, Inc. ----- POB 731695 • Puyallup WA 98373 ----- (253) 732-6515 MHeckert@Q.com October 16, 2020 Mr. Petr Marchenko 13220 42nd Ave E Tacoma WA 98446 Email: washingtonbesthomes@gmail.com Phone: 425-333-7737 RE: Critical Areas Designation (CAD) VEK on Aberdeen Townhomes Plat, LUA19-000280, ECF, MOD, PP, SA-H REVISED from City review of 7/8/2020 957 Aberdeen Ave NE- Parcel #3119900066 City of Renton, Washington Dear M. Marchenko, As requested we have evaluated Parcel 3119900066 property for jurisdictional wetlands, streams, and required buffers. The CAD wetland delineation encompassed the entire site, and offsite to sight limit of the periphery of the parcel. Location and Existing Conditions The property is located west of Aberdeen Ave NE in City of Renton, WA (fig. 1). This property is rectangular, 54,057 sq. ft. [ 1.24 acre]. The site contains a single-family house in the east. EXHIBIT 16 PLANNING DIVISION AWEIHS 03/04/2021 RECEIVED DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 2 Century Const. Renton CAD Report REV 2 Figure 1. Site Vicinity Methodology The site visit was conducted on June 21, 2018 February 13, 2020. A combination of field indicators, including: soils, vegetation, and hydrology, were used to determine whether wetlands were present. Onsite assessment followed the established criteria and methods as defined within the Corps of Engineers (CoE) Wetland Delineation Manual - 2010 Western Mountains, Valleys, and Coast (WMVC) Regional Supplement, Revised Washington State Wetland Rating System (WSWRS), and City of Renton Title 4-3-050. Wetlands are transitional areas between aquatic and upland habitats. In general terms, wetlands are lands where the extent and duration of saturation with water is the primary factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface (Cowardin et al., 1979). Wetlands are generally defined as "those areas that are inundated or saturated by surface water or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions." (City of Renton). Wetlands exhibit three (3) essential characteristics, all of which must be present for an area to meet the established criteria within the CoE Manual. These essential characteristics are: Hydrophytic Vegetation: Meaning a predominance of plants that are typically adapted for life in saturated soils, Hydric Soil: Meaning soils that are saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper horizons, and Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China (Hong Kong), Esri Korea, Esri (Thailand), NGCC, © OpenStreetMap contributors, and the GIS User Community DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 3 Century Const. Renton CAD Report REV 2 Wetland Hydrology: Meaning permanent or periodic inundation, or soil saturation to the surface, at least seasonally. Streams are delineated by identification of the Ordinary High Water Mark (OHWM). The definition of the OHWM as defined by the Washington State Department of Ecology as a part of the Shoreline Management Act is: “ . . . the mark on all lakes, streams, and tidal water that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation as that condition exists on June 1, 1971, as it may naturally change thereafter, or as it may change thereafter in accordance with permits issued by a local government or the department: Provided, That in any area where the ordinary high water mark cannot be found, the ordinary high water mark adjoining salt water shall be the line of mean higher high tide and the ordinary high water mark adjoining fresh water shall be the line of mean high water.” The boundary of the stream was flagged pink and labeled consecutively. Sample data points were flagged with pink and marked SP#1-2. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 4 Century Const. Renton CAD Report REV 2 Existing Documentation National Wetland Inventory (NWI) resources identify linear wetland (drainage) at the west boundary of the site (fig. 2). Figure 2. NWI Map – 1 in. = 500 ft. R4SBC PEM1Cx Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, © OpenStreetMap contributors, and the GIS User Community DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 5 Century Const. Renton CAD Report REV 2 City of Renton Critical Area data identifies an unnamed tributary to Johns Creek transecting the west of the site, confluencing with Johns Creek near the west boundary of project site (fig. 3). These streams are designated Type 4 (Type Ns) Streams. Figure 3. Renton Wetland Map – 1 in. = 250 ft. Johns Creek4Johns Creek4Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, © OpenStreetMap contributors, and the GIS User Community DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 6 Century Const. Renton CAD Report REV 2 The NRCS soils map identify soils on the site as: AkF Alderwood and Kitsap soils, very steep - not listed as hydric. RdC Ragnar-Indianola association, sloping - not listed as hydric. RdE Ragnar-Indianola association, moderately steep - not listed as hydric. WA Dept. of Fish & Wildlife Priority Habitat and Species data indicate no presence of priority habits or species on the site (attached). Field Observations The project site contains one primary upland and critical area. The eastern one-half of the parcel is on an elevated bench which contains the house and garage. West of this, the topography drops precipitously to a lower area, and then moderately slopes to the west. Upland Areas The project site contains one primary upland habitat area. Vegetation: The entire site is regrowth forest. Major plant species include alder (Alnus rubra), Douglas-fir (Pseudotsuga menziesii) and Himalayan blackberry (Rubus armeniacus). Johns Creek4Johns Creek4Ur RdC AkF RdE InC AgC DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 7 Century Const. Renton CAD Report REV 2 Soils: The soils throughout the project area consist of Alderwood Gravelly Sandy Loam (AgC). This soil parent material is basalt till with some volcanic ash and is moderately well drained. Soil plot data for the upland areas was 0-12 in. 10YR3/6 and 12-16 in. 10YR4/2 with no hydric soil indicators. Hydrology: Surface flow through the site is generally directed by topography from the east to west. A drainage transecting the site captures overland flow and directs it west to Johns Creek at the west boundary. Wetlands A small wetland occurs, associated with the drainage in the west portion of the site. The drainage course flows approximately through the center of the site going west. Streams A ditch transects the site from the center of the north boundary to the west boundary, through the center of the site. This drainage originates at a detention pond on the parcel adjacent offsite to the north, which drains through a 12 in. culvert to the head of the drainage. The drainage is deeply incised and actively eroding. iv. Type Ns: Waters that do not contain fish or fish habitat and have intermittent flows. These are seasonal, non-fish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np Water. Ns Waters must be physically connected by an above-ground channel system to Type S, F, or Np Waters. Off Site No other wetlands occur within sight distance of project boundaries. Pertinent Regulation City of Renton Title IV DEVELOPMENT REGULATIONS Chapter 3 ENVIRONMENTAL REGULATIONS AND OVERLAY DISTRICTS 4-3-050 CRITICAL AREAS REGULATIONS G. DEVELOPMENT STANDARDS: 7. Streams and Lakes: a. Classification System: The following classification system is hereby adopted for the purposes of regulating Streams and Lakes in the City. This classification system is based on the State’s Permanent Water Typing System WAC 222-16-030. Stream and lake buffer widths are based on the following rating system: i. Type S: Waters inventoried as “Shorelines of the State” under chapter 90.58 RCW. These waters are regulated under Renton’s Shoreline Master Program Regulations, RMC 4-3- 090. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 8 Century Const. Renton CAD Report REV 2 ii. Type F: Waters that are known to be used by fish or meet the physical criteria to be potentially used by fish and that have perennial (year-round) or seasonal flows. iii. Type Np: Waters that do not contain fish or fish habitat and that have perennial (year- round) flows. Perennial stream waters do not go dry any time of a year of normal rainfall. However, for the purpose of water typing, Type Np waters include the intermittent dry portions of the perennial channel below the uppermost point of perennial flow. iv. Type Ns: Waters that do not contain fish or fish habitat and have intermittent flows. These are seasonal, non-fish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np Water. Ns Waters must be physically connected by an above- ground channel system to Type S, F, or Np Waters. b. Non-regulated: Waters that are considered “intentionally created” not regulated under this Section include irrigation ditches, grass-lined swales and canals that do not meet the criteria for Type S, F, Np, or Ns Non-regulated waters may also include streams created as mitigation. Purposeful creation must be demonstrated through documentation, photographs, statements and/or other persuasive evidence. Findings The drainages on the site do not meet the criteria for definition as a “stream”. The water source is “unnatural” in that it is derived from a stormwater system on the parcel to the north which focuses flow and forces it to the drainage course. This water is diverted from the stream to the north into the on-site drainage. The substantial erosion indicates a recent change in flow regime is altering the stream morphology. The stream flows west from the site to a culvert under State Hwy. 167. The drainage flows approximately 340 ft. in the culvert. Daylighting on the west berm of hwy 167, the drainage flows immediately into the stormwater sewer system. The storm drain flows south for 1,000 ft., then west 1,000 ft. south of Fry’s Electronics, then north 2,000 ft., daylighting again at the north berm of Southport Dr. “Ns Waters must be physically connected by an above-ground channel system to Type S, F, or Np Waters.” Because this drainage traverses over 4,000 ft. in the underground stormwater system, it is not “physically connected by an above-ground channel system to Type S, F, or Np Waters.” However, per City GIS Maps, Johns Creek is identified as a type Ns Stream. Per RMC 4-3- 050E.5.a, the reclassification of a water body to a lower class requires Administrator acceptance of a stream or lake study, followed by a legislative amendment to the map in subsection E of RMC 4-3-050 prior to its effect. Therefore, while the critical area study states that the streams on site do not meet the definition of a Type Ns stream, the streams would be regulated as Type Ns streams, unless a legislative amendment was requested and approved. WETLAND DETERMINATION Wetland determination was based on sample plots which contained hydrophytic vegetation, hydric soils, and wetland hydrology in accordance with the CoE Manual. Based on these methods one wetland was identified within the project site. Two areas were identified as un- regulated water type. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 9 Century Const. Renton CAD Report REV 2 WETLAND SIZE (square feet) City of Renton CATEGORY WA WETLAND RATING SCORE GENERAL BUFFER WIDTH Adjustment by Function And Land Use Buffer Total A *541 3 17 75 +0 75 *Wetland Continues offsite Wetland A: This wetland was located in the western portion of the site and offsite along the west boundary. Hydrology for this wetland was provided by surface ponding of storm water and runoff from drainage flowing through the wetland. Since this wetland scored 17 points by WSWRS, this wetland appeared to meet the criteria for designation as a City of Renton Category III (3) Wetland. Based upon the criteria, the buffer appears to be unchanged from the generalized Buffer Width. Stream: Two drainages were identified in the west of the site. These drainages do not have a surface connection to Type S, F, or Np streams. However, the City has determined them to be Type Ns Streams. Type Ns streams mandate a 50-ft. buffer as measured perpendicular to the Ordinary High-Water Mark. WETLAND FUNCTION AND VALUE ASSESSMENT Wetlands are known to perform significant roles in the ecosystem, some of which are of immediate value to society. These roles vary greatly with the size, type, hydrology, vegetation, and location of wetland areas. Although the ecological functions performed by these wetlands are complex, interrelated, and difficult to assess and quantify, methods have been developed for the U.S. Army Corps of Engineers (USACE, 2010). The functions provided by wetlands include hydrologic support, shoreline protection, stormwater and floodwater storage, water quality, groundwater recharge, and provision of wildlife habitat. CATEGORIZATION BASED ON FUNCTIONS The functions that a wetland performs are characterized by answering a series of questions that note the presence, or absence, of certain indicators. Indicators are easily observed characteristics that are correlated with quantitative or qualitative observations of a function (Hruby et al. 2000). Depressional or Flats Wetlands Potential to Improve Water Quality Potential to Reduce Flooding and Stream Erosion Riverine and Freshwater, Tidal Fringe Wetlands Potential to Improve Water Quality Potential to Reduce Flooding and Stream Erosion Opportunity to Reduce Flooding and Stream Erosion Lake-fringe Wetlands Potential to Improve Water Quality Opportunity to Improve Water Quality Potential to Reduce Shoreline Erosion Opportunity to Protect Resources from Shoreline Erosion DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 10 Century Const. Renton CAD Report REV 2 Slope Wetlands Potential to Improve Water Quality Opportunity to Improve Water Quality Potential to Reduce Flooding and Stream Erosion Opportunity to Reduce Flooding and Erosion Functions Related to Habitat for All Classes of Wetlands Potential to Provide Habitat Opportunity to Provide Habitat Score and Category Based on Functions Wetlands that are Category I based on functions need to score 23-27 points. Total scores between 20-22 are Category II; 16-19 are Category III, and less than 16 are Category IV. ONSITE WETLAND VALUATION The wetland areas identified within the overall project area were evaluated following the functional value assessment process noted above. As identified in this assessment Wetland A would be considered to have the overall functional rating of Category III. · Water Quality Functions – 6 points · Hydrologic Functions – 7 points · Habitat Functions – 4 points · TOTAL score for functions – 17 Proposed Site Development The applicant is requesting a land use permit to construct 12 townhome units with private garages, and residential amenities on the eastern portion of the subject 1.24-acre parent property. All construction and improvements will take place outside of the high erosion hazard area, steep slope and wetland buffers. The proposed townhome units will be 2 to 4 bedrooms and will range in size from approximately 2,000 Sf to 3,000 SF. The parent lot will also be subdivided into 12 unit-lots through a preliminary plat process. All development actions will respect the drainage category and buffer determined on review. If you have questions or need additional information please contact me at 253.732.6515 or by email at mheckert@q.com. Respectfully Submitted, Mark Heckert, President Att. Wetland Delineation Map Wetland Rating form Sample plot data WDFW PHS report DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 """"!!!!!!!!!!!!A !A !A !A !A!A !A DETENTION POND 541 SQ. FT. CAT. III WETLAND 75-FT. BUFFER BOUNDARY STEAM BUFFER BOUNDARYREDUCED TO TOP OF SLOPEPER CITY OF RENTONA4A3SP21 INCISED 10FT STORM DRAIN W/ INLETS OUTLET PIPEDETENTION POND T Y P E N s S T R E A M Beaver Creek Environmental ServicesMHeckert@Q.com253 732 6515 Date: 10/21/2020 Att. 3Century Renton SiteParcel #3119900066Wetland Delineation MapFrom Survey 0 50 10025Feet1 inch = 50 feet µ DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 CENTURY CONSTRUCTION WETLAND BUFFER MITIGATION PLAN 957 Aberdeen Ave NE City of Renton, Washington King County Parcel no 3119900066 VEK on Aberdeen Townhomes Plat, LUA19-000280, ECF, MOD, PP, SA-H prepared for: Mr. Petr Marchenko 13220 42nd Ave E Tacoma WA 98446 Email: washingtonbesthomes@gmail.com Phone: 425-333-7737 Prepared by Beaver Creek Environmental Services, Inc. POB 731695 Puyallup, WA 98373 253 732-6515 MHeckert@Q.com REV. 1 February 22, 2021 DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 EXECUTIVE SUMMARY The Century Construction project, 957 Aberdeen Ave NE, King County Parcel no. 3119900066 is located generally in the City of Renton, Washington. The project site is approximately 54,057 sq. ft. [ 1.24 acre]. The site contains a single -family house in the east. As part of the site planning process an assessment of the project site was completed following the procedures outlined in the Washington State Wetlands Identification and Delineation Manual (Wash. Manual) and the Corps of Engineers Wetland Delineation Manual (2010 Supplement). Drainage corridors were also assessed in accordance with the criteria established by City of Renton and the State of Washington Department of Natural Resources (WDNR) Forest Practice Rules (WAC 222 -16-030). These assessment activities resulted in the identification of one wetland area and two streams (See Critical Areas Designation VEK on Aberdeen Plat, Century Construction, BCES, July 16, 2020). The site is encumbered by wetlands, streams, and their buffers. The selected site development actions for this project site is the development of a multi- family community consistent with City of Renton comprehensive plan and local land use zoning. Through site planning the project team has been able to design the structures and associated utilities and access to avoid adversely impacting the identified onsite wetlands or stream. However, to obtain reasonable use of the parcel to accommodate a multi-family development, the buffer of the on-site wetlands and the stream will be reduced to accommodate the stormwater pipe and outlet block. To mitigate for the encroachment into the standard buffer, the wetland area on site will be revegetated with native trees and shrubs. The area of impact from the tight line system and discharge pad is 268 sq. ft.(Encompass Engineering, pers. comm.). The drainpipe as it transects the stream buffer is 168 ft. long. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 TABLE OF CONTENTS INTRODUCTION............................................................................................................. 1 STUDY PURPOSE ......................................................................................................... 1 SITE DESCRIPTION ..................................................................................................... 1 MITIGATION PLAN ....................................................................................................... 1 DESCRIPTION OF THE MITIGATION PROGRAM ................................................... 3 GOAL AND OBJECTIVE OF THE MITIGATION PLAN ........................................... 4 SELECTED PLANT COMMUNITIES .......................................................................... 5 RESTORATION PLANTING GUIDELINES ........................................................... 6 CONSTRUCTION INSPECTION ................................................................................. 6 MITIGATION CONSTRUCTION SCHEDULE ........................................................... 8 SEEDING FOR EXPOSED BUFFER AREA .............................................................. 11 CONTINGENCY PLAN .............................................................................................. 11 PLANTING NOTES ..................................................................................................... 11 WETLAND MITIGATION PERFORMANCE BOND ............................................... 12 REFERENCE LIST ........................................................................................................ 14 ATTACHMENT 1 - 1Mitigation Plan Drawing ….……………………………….......15 ATTACHMENT 2 - Bond Quantity Worksheet ………………………………………16 ATTACHMENT 3 – Site Plan ………...………………………………..17 DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 STANDARD OF CARE Prior to extensive site planning, this document should be reviewed and the wetland boundaries verified by the appropriate resource and permitting agencies. Wetland boundaries, wetland classifications, wetland ratings, proposed buffers, and proposed compensatory mitigation should be reviewed and approved by City of Renton Planning dept. personnel and potentially other resource agency staff. Beaver Creek Environmental Services, Inc. (BCES) has provided professional services that are in accordance with the degree of care and skill generally accepted in the nature of the work accomplished. No other warranties are expressed or implied. BCES is not responsible for design costs incurred before this document is approved by the appropriate resource and permitting agencies. Mark Heckert BCES DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 1 18033 – Cent Rent MitPlan REV 1 INTRODUCTION This report details activities to mitigate for unavoidable impacts to regulated City of Renton Environmentally Critical Areas as an initial element of the site planning process for the Century Construction development (Parcel # 3119900066). The project site is approximately 54,057 sq. ft. [ 1.24 acre]. The site is bounded on the north, east, and south by residential development, and on the west by State Hwy. 167. The site is a single-family residence. STUDY PURPOSE This purpose of this document is to present the plan for mitigation of unavoidable impacts to the regulated wetland and stream buffers within the project site. This study was designed to accommodate site planning and potential regulatory actions. This report is suitable for submittal to federal, state, and local authorities for wetland boundary verification and permitting actions. SITE DESCRIPTION The site is rectangular, approximately 54,057 sq. ft.. Recent past use is as a single-family house site. It is elevated in the east and drops precipitously in the west. MITIGATION PLAN The selected site development actions for the Century Construction is the development of a multi-family residence community consistent with City of Renton comprehensive plan and local land use zoning. The creation of this community will include the establishment of multi-family structures and internal access for driveway and utilities. Through site planning the project team has b een able to design the homesites and associated utilities to avoid adversely impacting the identified onsite wetlands and stream. Because of the precipitous nature of the site, collected stormwater must be released where the stream channel gradient diminishes. Stormwater will be transported to the Rock -lined Pipe Discharge Protector by elevated pipe (see detail). The pipe traverses 168 ft. of wetland buffer to the 50 sq. ft. Discharge Protector. This results in a permanent impact to the wetland buffer of 268 sq. ft. *Note: This pipe does NOT cross the regulated stream feature. This encroachment into the identified buffer for the on-site wetlands is required to establish the home sites. The proposed development is the minimum required to achieve reasonable use of the site. The development is situated as far from the wetland and stream as practicable. Per RMC 4-3-050J.2.b.iii, new utility routes shall avoid paralleling the stream or following a down-valley course near the channel. Bever Creek Environmental Services has DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 2 18033 – Cent Rent MitPlan REV 1 reviewed the Tree Retention Plan by Encompass Engineering & Surveying dated 12/11/2020 (see attached) to assess compliance with this code requirement. The proposed storm line that passes through the stream buffer avoids paralleling the stream to the greatest extent feasible, while still meeting tree retention and the storm discharge location requirements of the Geotechnical Engineer of Record. Per page 11 of the Revised Geotechnical Engineering Report by the Riley Group (see attached), stormwater directed toward the downstream steep slope must be piped in a closed conduit installed on the slope face and discharged beyond the toe of the slope. Therefore, the proposed outfall location was selected in order to allow the tightline stormwater pipe to discharge beyond the toe of slope, where grades are less than 15%. In addition, the proposed tightline stormwater pipe alignment was selected in order to avoid disturbance of all protected significant trees within the Critical Area Tract per City code requirements. In order to connect the required tightline system to the outfall location with min imal disturbance of significant trees, the stormwater pipe must parallel the stream for a short portion of the alignment. The proposal avoids paralleling the stream to the maximum extent feasible, while still meeting Critical Area Tract tree retention requ irements and the storm discharge location requirements of the Geotechnical Engineer of Record. MITIGATION SEQUENCING This mitigation plan follows the required mitigation sequencing of Avoidance, Minimization, Mitigation. Avoidance: All project elements moved outside wetland buffer boundary, except the pipe and outlet, which must be located at the outlet elevation for flow. The project does NOT cross the creek, which avoids stream impacts. Minimization: The pipe is the minimum length necessary to site the splash block, which must by code be in that elevation. The pipe is directed so to avoid all trees through the buffer. Mitigation: The on-site wetland, which is depauperate of vegetation, will be enhanced by planting trees and shrubs. Mitigation for the required buffer impact will be provided by replanting the wetland with a variety of native trees and shrubs. Through this compensatory mitigation the development would not result in a “net loss” of regulated wetland area, function, or value consistent with City of Renton Zoning Code. Impact Area Analysis – (in sq. ft.) Area Development Impact Mitigation Enhancement Mitigation ratio Enhanced to reduced Buffer – Wetland A & Stream 268 282 ON-SITE WETLAND 1.1 to 1 TOTAL 268 282 1.1 to 1 DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 3 18033 – Cent Rent MitPlan REV 1 Fencing: A fence will be installed at the modified buffer boundary of Stream A at the top of the slope. City of Renton wetland buffer boundary will be attached every 100 ft.. No further activity will occur within the fenced area once enhancement planting is complete. The existing wetland buffer in the interior of the site has been severely degraded by erosion and prior management and is bare ground. Potential impacts to habitat from the development are: 1). Short-term construction disruption. This impact will be mitigated thru the placement of silt fence barriers in every area which may flow into the wetland and stream (see Century Construction Site Civil Plans, Erosion Control Plan) and oversight by the project biologist during construction. The project biologist will observe and consult with construction crews during construction to ensure compliance with best management practices during the excavation of the buffer area. 2). Long-term impacts from development: a). Permanent loss of habitat area. There will be no functional loss of habitat area. The present wetland and buffer in the mitigation area is moderate functional. Functional buffer area will increase as a result of installation of trees and habitat structures. b). Loss of habitat utility due to light and noise from the development and increased visitation by people. Lighting of the developed area will increase “spill-over” of light to the mitigated buffer and wetland. All lighting will be directed away from the mitigation area. The boundary fence will be a 2-post cedar fence to inhibit intrusion by people. MITIGATION FUNCTIONAL COMPARISON ENVIRONMENTAL FUNCTION EXISTING PROPOSED Hydrological Support Function Low Moderate Stormwater Storage Function High High Floodwater Storage Function moderate High Water Quality Function low High Groundwater Recharge Function Moderate Moderate Natural Biological Functions Low High Education and Recreational Opportunities Low moderate Threatened and Endangered Species low Moderate (after Adamus et al. 1987: Reppert et al. 1979) DESCRIPTION OF THE MITIGATION PROGRAM DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 4 18033 – Cent Rent MitPlan REV 1 1. As mitigation for the unavoidable impact to 268 sq. ft. of City of Renton regulated Category 3 Wetland buffer and Type Ns Water buffer, the retained on site wetland of 282 sq. ft. will be enhanced with native trees and shrubs. The wetland area to be enhanced is presently dominated by bare ground and ag invasives. Supportive hydrology will continue to be provided by the existing wetlands and stream corridor. 2. Temporary and long-term erosion control measures will be implemented (see Century Construction Site Civil Plans erosion control Plan). These measures include silt fencing during site preparation and buffer enhancement and planting of new vegetation. 3. All onsite activities will be monitored by the project biologist. Following the completion of onsite planting activities a "record-drawing" plan will be prepared and submitted to City of Renton. A five-year monitoring program will be undertaken to assure the success of the wetland and buffer enhancement program. A series of financial guarantees will also be implemented to assure that the proposed work is completed and is successful. 4. The outer boundaries of the established buffer tract would be marked wi th standard City of Renton buffer boundary signs. The buffer boundaries will be fenced to limit human intrusions between the upland boundary of the remaining buffer and th e developed portion of the site. In addition, the project team will remove the trash, debris, and invasive shrubs within the retained wetland and buffer areas. 5. Wetland, stream and buffer vegetation cleared or otherwise damaged during the installation of the mitigation plan shall be revegetated with appropriate native plants installed at an appropriate density to restore the damaged condition. These plants shall be subject to the same performance standards indicated in the mitigation plan. GOAL AND OBJECTIVE OF THE MITIGATION PLAN The GOAL of the Mitigation Plan is to fully compensate for the unavoidable adverse impact to regulated buffer areas. Upon the completion of this mitigation plan there will be no net loss of wetland acreage, functions, or values; and an increase in the potential for the buffer to protect aquatic habitats. To achieve the defined GOAL, the following OBJECTIVES and PERFORMANCE CRITERIA have been established to apply to the compensatory mitigation wetland area.: Objective A. The retained & enhanced wetland area will total 282 sq. ft. and be located in the southwest corner of the site. The enhanced wetland will be hydrologically connected to the adjacent City of Renton Type Ns Stream. The enhanced wetland area will exhibit a scrub/shrub vegetation class within five years following initial planting. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 5 18033 – Cent Rent MitPlan REV 1 Performance Criterion #A1: As defined by plant counts 100% of the shrubs installed as a part of the initial planting phase will be alive at the end of the first growing season. Performance Criterion #A2: As defined by plant counts 80% of the shrubs installed as a part of the initial planting phase will be alive at the end of the fifth growing season. Performance Criterion #A3: As defined by aerial cover, invasives will cover less than 10% of the planting area in any one year. Objective B. The enhanced mitigation wetland area will total 282 sq. ft. and be located at the southwest corner of the site. The enhanced wetland will be hydrologically connected to City of Renton Type Ns Stream. The enhanced wetland area will exhibit a tree vegetation class within five years following initial planting. Performance Criterion #B1: As defined by plant counts 100% of the trees installed as a part of the initial planting phase will be alive at the end of the first growing season. Performance Criterion #B2: As defined by plant counts 80% of the trees installed as a part of the initial planting phase will be alive at the end of the fifth growing season. Performance Criterion #B3: As defined by aerial cover, invasives will cover less than 10% of the planting area in any one year. SELECTED PLANT COMMUNITIES The plant communities and plants selected for the enhanced wetland area will be obtained as nursery stock. These selected species are native and commonly occur in the local area. The plant species prescribed are selected to increase plant diversity, match present onsite communities, increase wildlife habitats, and enha nce the aquatic environment. Plantings will be located as depicted on the attached Century Construction Mitigation Plan drawing. PLANTING AREA: RETAINED WETLAND – 282 sq. ft. @ 12-ft on center = 4 trees 282 sq. ft. @ 8-ft on center = 8 shrubs COMMON NAME SCIENTIFIC NAME LOCATION PROPOSED SPACING (oc) PROPOSED SIZE INDICATOR STATUS TREE 2 Pacific willow(SAL) Salix lasiandra WETLAND 12 ft. 2 Gal. FACW DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 6 18033 – Cent Rent MitPlan REV 1 2 Sitka spruce (PIS) Picea sitchensis WETLAND 12 ft. 2 Gal. FAC SHRUB 4 Red-osier dogwood (COS) Cornus stolonifera WETLAND 8 ft 1 gal FACU 4 Sitka willow (SAS) Salix sitchensis WETLAND 8 ft. 2 Gal. FACW RESTORATION PLANTING GUIDELINES 1. Trees 12’ O.C., (this assumes 2-5 gal. size) 2. Plus shrubs 8’ O.C.,(this assumes 1-2 gal. size); CONSTRUCTION INSPECTION Essential to the success of the compensatory mitigation program is the accurate inspection of onsite activities immediately prior to and during the wetland creation and planting phases. These activities include pre-construction site inspection, onsite inspection and technical direction during wetland creation and planting activities, and post - creation/planting site inspection and evaluation. The pre-creation site inspection allows the project proponent and the project biologist to evaluate and, if necessary, adjust the onsite construction steps. These steps include analysis of project site elevation features, project sequencing and timing, final grade analysis, unforeseen required minor modifications to the original establishment plan, and the establishment of environmental protections (silt fences, etc.) required during construction. Interaction with City of Renton wetland staff is also an essential element during pre-construction site inspections and discussions. Onsite technical inspection during construction and planting activities will be implemented by the project biologist. The project biologist will perform oversight and address minor unforeseen difficulties to assure that the intent of the wetland mitigation plan is met. The project biologist shall also be responsible for ensuring that the species and sizes of native plants selected are utilized during initial planting. If selected native species become unavailable, the project biologist will consult with City of Renton wetland staff for substitute plant species to ensure that the intent of the wetland mitigation plan is met. Post -creation site inspection/evaluation will include the preparation of a "record -drawings” which will be submitted to City of Renton wetland staff. VEGETATION MAINTENANCE PLAN Maintenance of the created wetland and buffer plant communities may be required to assure the long-term health and welfare of the wetland's and buf fer's environmental functions. The overall objective is to establish undisturbed plant communities that do not require maintenance. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 7 18033 – Cent Rent MitPlan REV 1 Activities will include, but are not limited to, the removal of invasive non-native vegetation and the additional irrigation of selected areas. Established maintenance activities include the removal of any trash within the buffer. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 8 18033 – Cent Rent MitPlan REV 1 MITIGATION CONSTRUCTION SCHEDULE PROJECT TASK TASK SCHEDULE (on or before) Onsite pre-creation meeting January 2021 Placement of protective fencing, final marking, and identification of work area. January 2021 Planting of wetland mitigation March 2021 Record-drawings report to City May 2021 RMC 4-3-050L- a-ii.PROJECT MONITORING Following the successful completion of the proposed compensatory mitigation plan a five- year monitoring and evaluation program will be undertaken. The purpose of this program is to assure the success of the selected mitigation as measured by an establishe d set of performance criteria (see above). This monitoring will also provide valuable information on the effectiveness of mitigation procedures. STANDARDS OF SUCCESS Vegetation Sampling Methodology and Monitoring Schedule Permanent vegetation sampling plots will be located within each planting community in areas representative of the communities being sampled. These sampling plots will be located along specific transects and at stationary identified points. Observations and measurements will be recorded for all plant species in order of dominance based on the relative percent cover for each species within the various vegetation strata. Sampling for tree and shrub species will be completed in 30-foot radius sampling plots. Stratified methods will be u sed to increase the precision of sampling data while also maintaining elements necessary for statistical inferences. The evaluation of the success of the enhancement program will be based on the expected cover percentages and the selected 80% survival ra te. These defined threshold criteria will be applied at the times of yearly monitoring. The percent of aerial cover and the percent survival rate will be based on combined counts of existing and planted species during vegetation monitoring. Sample locat ion will be shown on the design and the "record drawings" plans, and will correspond to identified photo points. Trees and shrubs will be visually evaluated to determine the rate of survivorship, health, and vigor of each plant. The categories to be used will include live, stressed, tip dieback, basal sprouts, not found, apparently dead, and dead. Vegetation Monitoring will include: DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 9 18033 – Cent Rent MitPlan REV 1 1. Upon the completion of initial planting and as a part of each monitoring period the project biologist will count the number of live plants which were planted within the buffer area. Plants will be identified to species and observations of general plant condition (i.e., plant health, amount of new growth) are to be recorded for each plant. 2. At identified sample plots within the enhanced buffer areas the project biologist will determine percent coverage of vegetation using the Canopy Coverage Method sampling (0.85 m2 plot frame) procedure for emergent species and by using the Line-intercept Method sampling procedure for the scrub/shrub and sapling tree species. 3. Within the entire mitigation area the project biologist will count the number of undesirable invasive plants and estimate the aerial coverage (as if the observer were looking straight down from above) of these invasive plants. Undesirable plants include blackberries, Scot’s broom, tansy ragwort, and other such plants listed in the Washington State Noxious Weed List. 4. Within the sample plots mitigation area the project biologist will count the number of desirable "volunteer" plants and estimate the aerial coverage of these plants. 5. The project biologist will take photographs that show the entire mitigation area. During the five-year monitoring period photos will be taken in the same direction and at the same location to provide a series of photos. These photos will show plant growth, plant species, and plant coverage. 6. Upon the completion of the initial project planting and upon the completion of each monitoring period the project biologist will prepare a report defining methods, observations, and results along with the date the observations were completed and photos. Each report will be sent to: The City of Renton. 7. The monitoring schedule is defined as: A. At the completion of initial project planting. This report will include a “record drawing” defining the species used, locations, and general site conditions. This report will also include a “lessons learned” section to assist in future monitoring and final project assessment. This “record drawing” and report will be provided to the City within two weeks after the completion of onsite planting. B. At 30 days following initial project area planting. This “30-day” report will be provided to the City within two weeks after the completion of onsite monitoring. Depending upon the date of completion of the initial onsite planting the “30 -day” monitoring may overlap with the start of the “year-1” monitoring. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 10 18033 – Cent Rent MitPlan REV 1 C. Vegetation community monitoring once a year for five years following the completion of initial onsite planting. For each monitoring year, onsite monitoring will be completed once near the end of the growing season (mid-September). For each onsite monitoring activity a report will be prepared and provided to the City within two weeks after the completion of onsite monitoring. The last monitoring report will include notification to the City biologist that the monitoring program has concluded and that City review and site inspection is required for project analysis and release of the f inancial guarantee. This final report will also include a “lessons learned” section to assist and final project assessment and to potentially assist in the evaluation other mitigation projects. RMC 4-3-050L-a-ii. Vegetation Monitoring Sequencing IDENTIFIED TASK DATE OF COMPLETION (on or before) First growing season fall plant inspection September 30, 2021 First growing season fall report October 15, 2021 Second growing season fall plant inspection September 30, 2022 Second growing season fall report October 15, 2022 Third growing season fall plant inspection September 30, 2023 Third growing season fall report October 15, 2023 Fourth growing season fall plant inspection September 30, 2024 Fourth growing season fall report October 15, 2024 Fifth growing season fall plant inspection September 30, 2025 Fifth growing season fall report October 15, 2025 WILDLIFE OBSERVATIONS Observations of wildlife will coincide with the onsite activities undertaken as part of the Vegetation Monitoring Program. The onsite team will document the extent of bird species abundance, site utilization, nesting and feeding activities, and species diversity. In addition, documentation of terrestrial and aquatic reptiles, amphibians, and mammals observable without trapping will also be documented. Wildlife observations will be documented within the Vegetation Monitoring Reports noted above. VEGETATION MAINTENANCE PLAN Maintenance of the created wetland and buffer plant communities may be required to assure the long-term health and welfare of the wetland's and buffer's environmental functions. Such maintenance would be identified during the DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 11 18033 – Cent Rent MitPlan REV 1 monitoring period and undertaken only following discussi on and coordination with City of Renton wetland staff. The overall objective is to establish undisturbed plant communities that do not require maintenance. Activities may include, but are not limited to, the removal of invasive non -native vegetation and the irrigation of selected areas. Established maintenance activities include the removal of any trash within the buffer. REMOVAL OF INVASIVE NON-NATIVE VEGETATION As a contingency, should the removal of invasive non -native vegetation become necessary, the project proponent will contact City of Renton wetland staff to establish and define specific actions to be taken. Resultant contingency plan activities will be implemented when the ongoing vegetation monitoring program indicates that plants listed in the Washington State Noxious Weed List and Scot's broom are becoming dominant in the community. SEEDING FOR EXPOSED BUFFER AREA Seeding for all exposed surfaces with in the buffer will be completed within two weeks following the completion of onsite grading. CONTINGENCY PLAN As a contingency, should the proposed compensatory plan fail to meet the performance criteria, the project proponent will undertake required remedial actions. Where plant survival is the failing component, the project proponent will replant and assure the success of this second planting which would be held to the same standard of success as measured by threshold criteria and monitoring processes. Should additional remedial actions be required, the project proponent will meet with City of Renton wetland staff to establish and define actions to be taken to meet the desired goal of this program. PLANTING NOTES All plant materials shall be native to the southern Puget Sound Region. The onsite biologist shall inspect plant materials to assure the appropriate plant schedule and plant characteristics are met. The project proponent shall warrant that all plants will remain alive and healthy for a period of one year following completion of planting activities. The project proponent shall replace all dead and unhealthy plants with plants of the same specifications. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 12 18033 – Cent Rent MitPlan REV 1 RMC 4-3-050L-a-i (financial resources) WETLAND MITIGATION PERFORMANCE BOND A Wetland Mitigation Performance Bond will be provided for this project. This bond will be held by the City of Renton and be equal to 125% of the actual estimated costs for identified activities. This increased percentage will allow for adequate funds to be available as a contingency should actions be required to meet the goals of these plans. The Performance Bond will be deemed to be released upon meeting the established threshold criteria and acceptance by the City of Renton of the required reporting documents after completion of the 5-year monitoring period. The amount of these guarantees shall be established as a part of the final mitigation plan. Construction Guarantee: (see Bond Quantity Worksheet, Attached) TASK ASSOCIATED COST Plants and installation $ 1701.00 Habitat Structures $.00 Erosion Control $ 240.00 Fencing 1795.00 Mobilization 374.00 30% contingency $1,120.00 CONSTRUCTION GUARANTEE TOTAL $5,230.00 Performance Guarantee TASK ASSOCIATED COST Onsite Maintenance ($1,000/yr. x 5 years) $ 5,000.00 Onsite Monitoring with report ($1,440/yr. 5 years) $ 7,200.00 PERFORMANCE GUARANTEE TOTAL $12,200.00 Per RMC 4-3-050L. Professional Qualification Mitigation Plan prepared by Mark Heckert Managing Principal of Beaver Creek Environmental Services, Inc.. Mark has an AAS in Fish & Wildlife Technology and a B.S. in Wildlife Science. Mark has 21 years’ experience in wetland delineation, impact assessment, and mitigation planning throughout the Puget sound region. Mark has completed the US Army CoE wetland training, Washington State Wetland Rating System, and numerous individual courses in wetland function and mana gement, and is preferred consultant in King & Pierce Counties and has authored 500+ accepted critical areas reports in 14 Puget Sound jurisdictions. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 13 18033 – Cent Rent MitPlan REV 1 DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 14 18033 – Cent Rent MitPlan REV 1 REFERENCE LIST Adamus, P.R., E.J. Clairain Jr., R.D. Smith, and R.E. Young. 1987. Wetland Evaluation Technique (WET); Volume II: Methodology, Operational Draft Technical Report Y-87, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Office of Biological Services, U.S. Fish and Wildlife Service, U.S. Department of the Interior, FWS/OBS-79/31. Environmental Laboratory. 1987. "Corps of Engineers Wetlands Delineation Manual," Technical Report Y-87-1, US army Engineer Waterways Experiment Station, Vicksburg, Miss. Hitchcock, C.L., A. Cronquist. 1977. Flora of the Pacific Northwest. University of Washington Press. Seattle, Washington. Reppert, R.T., W. Sigleo, E. Stakhiv, L. Messman, and C. Meyers. 1979. Wetland Values - Concepts and Methods for Wetland Evaluation. Research Report 79 -R1, U.S. Army Corps of Engineers, Institute for Water Resources, Fort Belvoir, Virginia. U.S. Army Corps of Engineers. 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0), ed. J. S. Wakeley, R. W. Lichvar, and C. V. Noble. ERDC/EL TR -10-3. Vicksburg, MS: U.S. Army Engineer Research and Development Center. U.S. Department of Agriculture, Soils Conservation Service. Soils Survey of King County Area Washington, February 1979. Washington State Department of Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Publication Number 96 -94. DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 STREAM MODIFIED BUFFER BOUNDARYFENCED & SIGNED 541 SQ. FT. CAT. III WETLAND282 SQ. FT. ONSITE MITIGATION AREATO BE PLANTED WITH4 TREES8 SHRUBS BUFFER IMPACTS:168 LINEAR FT. ELEVATED DRAINPIPE +50 SQ. FT. ROCK LINED PIPE DISCHARGE PROTECTOR PIPE DOES NOT CROSS STREAM 75-FT. BUFFER BOUNDARY 3119900066 3119900075 6056500100 0012600000 8128650000 7229350000 T Y P E N s S T R E A M BU FF ER B O U N D AR Y FEN C E Beaver Creek Environmental ServicesMHeckert@Q.com253 732 6515 Date: 2/23/2021 Att. 1Century Renton SiteParcel #3119900066WEST Portion DETAILBUFFER MITIGATION MAPFrom SurveyREV. 1 0 30 6015Feet1 inch = 34 feet µ DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 """"!!!!!!!!!!!!A !A !A !A !A!A !A DETENTION POND 541 SQ. FT. CAT. III WETLAND 75-FT. BUFFER BOUNDARY STEAM BUFFER BOUNDARYREDUCED TO TOP OF SLOPEPER CITY OF RENTONA4A3SP21 INCISED 10FT STORM DRAIN W/ INLETS OUTLET PIPEDETENTION POND T Y P E N s S T R E A M Beaver Creek Environmental ServicesMHeckert@Q.com253 732 6515 Date: 10/21/2020 Att. 3Century Renton SiteParcel #3119900066Wetland Delineation MapFrom Survey 0 50 10025Feet1 inch = 50 feet µ DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 Date: 10/20/19 Prepared by: Project Number: Applicant:Phone: PLANT MATERIALS (includes labor cost for plant installation) Type Unit Price Unit Quantity Cost PLANTS: Potted, 4" diameter, medium $5.00 Each $ - PLANTS: Container, 1 gallon, medium soil $11.50 Each 8.00 $ 92.00 PLANTS: Container, 2 gallon, medium soil $16.00 Each 4.00 $ 64.00 PLANTS: Container, 5 gallon, medium soil $36.00 Each $ - PLANTS: Seeding, by hand $0.50 SY $ - PLANTS: Slips (willow, red-osier)$2.00 Each $ - PLANTS: Stakes (willow)$2.00 Each $ - PLANTS: Stakes (willow)$2.00 Each $ - PLANTS: Flats/plugs $2.00 Each $ - TOTAL $ 156.00 Type Unit Price Unit Cost Compost, vegetable, delivered and spread $37.88 CY $ - Decompacting till/hardpan, medium, to 6" depth $1.57 CY $ - Decompacting till/hardpan, medium, to 12" depth $1.57 CY $ - Hydroseeding $0.51 SY $ - Labor, general (landscaping other than plant installation)$32.00 HR 10.00 $ 320.00 Labor, general (construction)$40.00 HR $ - Labor: Consultant, supervising $55.00 HR 5.00 $ 275.00 Labor: Consultant, on-site re-design $95.00 HR 10.00 $ 950.00 Rental of decompacting machinery & operator $70.00 HR $ - Sand, coarse builder's, delivered and spread $42.00 CY $ - Staking material (set per tree)$7.00 Each $ - Surveying, line & grade $250.00 HR $ - Surveying, topographical $250.00 HR $ - Watering, 1" of water, 50' soaker hose $3.62 MSF $ - Irrigation - temporary $3,000.00 Acre $ - Irrigation - buried $4,500.00 Acre $ - Tilling topsoil, disk harrow, 20hp tractor, 4"-6" deep $1.02 SY $ - TOTAL $ 1,545.00 ITEMS Unit Cost Unit Cost Fascines (willow) $ 2.00 Each $ - Logs, (cedar), w/ root wads, 16"-24" diam., 30' long $1,000.00 Each $ - Logs (cedar) w/o root wads, 16"-24" diam., 30'$400.00 Each $ - Logs, w/o root wads, 16"-24" diam., 30' long $245.00 Each $ - Logs w/ root wads, 16"-24" diam., 30' long $460.00 Each $ - Rocks, one-man $60.00 Each $ - Rocks, two-man $120.00 Each $ - Root wads $163.00 Each $ - Spawning gravel, type A $22.00 CY $ - Weir - log $1,500.00 Each $ - Weir - adjustable $2,000.00 Each $ - Woody debris, large $163.00 Each $ - Snags - anchored $400.00 Each $ - Snags - on site $50.00 Each $ - Snags - imported $800.00 Each $ - * All costs include delivery and installation TOTAL $ - EROSION CONTROL ITEMS Unit Cost Unit Cost Backfill and Compaction-embankment $ 4.89 CY $ - Crushed surfacing, 1 1/4" minus $30.00 CY $ - Ditching $7.03 CY $ - Excavation, bulk $4.00 CY $ - Fence, silt $1.60 LF 150.00 $ 240.00 Jute Mesh $1.26 SY $ - Mulch, by hand, straw, 2" deep $1.27 SY $ - Mulch, by hand, wood chips, 2" deep $3.25 SY $ - Mulch, by machine, straw, 1" deep $0.32 SY $ - Piping, temporary, CPP, 6"$9.30 LF $ - Piping, temporary, CPP, 8"$14.00 LF $ - Piping, temporary, CPP, 12"$18.00 LF $ - Plastic covering, 6mm thick, sandbagged $2.00 SY $ - Rip Rap, machine placed, slopes $33.98 CY $ - Rock Constr. Entrance 100'x15'x1'$3,000.00 Each $ - Rock Constr. Entrance 50'x15'x1'$1,500.00 Each $ - Sediment pond riser assembly $1,695.11 Each $ - Sediment trap, 5' high berm $15.57 LF $ - Sediment trap, 5' high berm w/spillway incl. riprap $59.60 LF $ - Sodding, 1" deep, level ground $5.24 SY $ - Sodding, 1" deep, sloped ground $6.48 SY $ - Straw bales, place and remove $600.00 TON $ - Hauling and disposal $20.00 CY $ - Topsoil, delivered and spread $35.73 CY $ - TOTAL $ 240.00 INSTALLATION COSTS ( LABOR, EQUIPMENT, & OVERHEAD) HABITAT STRUCTURES* Critical Areas Mitigation City of Renton Bond Quantity Worksheet Description Mark Heckert Project Description: Wetland buffer Avg. Restoration/Enhancement Site Project Name: CENTURY CONST, RENTON MITIGATION AREA Location: Parcel # 3119900066 CENTURY CONSTRUCTION DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2 GENERAL ITEMS ITEMS Unit Cost Unit Cost Fencing, chain link, 6' high $18.89 LF $ - Fencing, chain link, corner posts $111.17 Each $ - Fencing, chain link, gate $277.63 Each $ - Fencing, split rail, 3' high (2-rail)$10.54 LF 170.00 $ 1,791.80 Fencing, temporary (NGPE)$1.20 LF $ - Signs, sensitive area boundary (inc. backing, post, install)$28.50 Each $ - TOTAL $ 1,791.80 $ 3,732.80 ITEMS Percentage of Construction Cost Unit Cost Mobilization 10%1 $ 373.28 Contingency 30%1 $ 1,119.84 TOTAL $ 1,493.12 MAINTENANCE AND MONITORING Maintenance, annual (by owner or consultant) Less than 1,000 sq.ft. and buffer mitigation only $ 1.08 SF $ - Less than 1,000 sq.ft. with wetland or aquatic area mitigation $ 1.35 SF 1410.00 $ 1,903.50 Larger than 1,000 sq. ft. but less than 5,000 sq.ft. of buffer mitigation $ 180.00 EACH $ - Larger than 1,000 sq. ft. but less than 5,000 sq.ft. of wetland or aquatic area mitigation $ 270.00 EACH $ - Larger than 5,000 sq.ft. but < 1 acre -buffer mitigation only $ 360.00 EACH $ - Larger than 5,000 sq.ft. but < 1 acre with wetland or aquatic area mitigation $ 450.00 EACH $ - Larger than 1 acre but < 5 acres - buffer and / or wetland or aquatic area mitigation $ 1,600.00 DAY $ - Larger than 5 acres - buffer and / or wetland or aquatic area mitigation $ 2,000.00 DAY $ - Monitoring, annual (by owner or consultant) Larger than 1,000 sq.ft. but less than 5,000 wetland or buffer mitigation $ 720.00 EACH $ - Larger than 5,000 sq.ft. but < 1 acre with wetland or aquatic area impacts $ 900.00 EACH $ - Larger than 1 acre but < 5 acres - buffer and / or wetland or aquatic area impacts $ 1,440.00 DAY $ - Larger than5 acres - buffer and / or wetland or aquatic area impacts $ 2,160.00 DAY $ - TOTAL $ 1,903.50 Total $7,129.42 NOTE: Projects with multiple permit requirements may be required to have longer monitoring and maintenance terms. This will be evaluated on a case-by- case basis for development applications. Monitoring and maintance ranges may be assessed anywhere from 5 to 10 years. (Construction Cost Subtotal) OTHER (16 hrs @ $90/hr) (24 hrs @ $90/hr) (10 hrs @ $45/hr) (WEC crew) (1.25 X WEC crew) (8 hrs @ 90/hr) (10 hrs @ $90/hr) (4hr @$45/hr) (8 hrs @ 45/hr) (3 X SF total for 3 annual events; Includes monitoring) (3 X SF total for 3 annual events; Includes monitoring) (6hr @$45/hr) DocuSign Envelope ID: 69D0A746-C343-49C8-931A-17990D5283F2