Loading...
HomeMy WebLinkAboutEx_12_Stream_Buffer_Restoration_Plan March 4, 2024 AOA-6644 John Kay john@kplusarchitects.net SUBJECT: New Life Church Frontage Improvements Stream Buffer Restoration 15711 -152nd Ave. SE, Renton, WA (Parcel 232305-9021) Dear John: We have prepared the attached stream buffer restoration plan (W1 through W4) for unavoidable temporary impacts to the buffer of Madson Creek associated with the installation of a utility line within the Maple Valley Highway (SR 169) right-of-way. 1.0 EXISTING CRITICAL AREAS Madson Creek flows from east to west south of the required frontage improvements and utility line installation. The ordinary high water (OHW) of the north side of the creek was delineated on January 25, 2024 and was subsequently surveyed. Madson Creek is a Type F stream and requires a standard 115-foot buffer. The 115- foot buffer from the stream extends north through the right-of-way and SR 169. No wetlands were observed adjacent to the creek. 2.0 TEMPORARY BUFFER IMPACTS AND CRITICAL AREA RESTORATION Following installation of the utility line all temporarily disturbed buffer areas will be restored and enhanced with native vegetation. Most of the disturbed area in the eastern portion of the right-of-way is mowed grass, while the western portion of the disturbance area was dominated primarily by Himalayan blackberry (Rubus armeniacus) with patches of native shrubs. 2.1 Goal, Objectives, and Performance Standards for Restoration Area The primary goal of the restoration plan is to restore and enhance the stream buffer that will be temporarily impacted by the utility line installation. To meet this goal, the following objectives and performance standards have been incorporated into the design of the plan: DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A John Kay March 4, 2024 Page 2 of 3 Objective A: Increase the structural and plant species diversity within the restoration areas. Performance Standard: There will be 100% survival of all planted species throughout the restoration areas at the end of the first year of planting. Following Year 1, success will be based on an 80% survival rate and areal cover of planted or recolonized native species of 15% after Year 1, 20% after Year 2, 30% after Year 3, and 50% at Year 5. Objective B: Limit the amount of invasive and exotic species within the restoration areas. Performance Standard: After construction and following every monitoring event for a period of at least five years, exotic and invasive plant species will be maintained at levels below 10% total cover in all planted areas. 2.2 Construction Management Prior to commencement of any work in the restoration areas, the clearing limits will be staked and all existing vegetation to be saved will be clearly marked. A consultant will supervise plan implementation during construction to ensure that objectives and specifications of the mitigation plan are met. Any necessary significant modifications to the design that occur as a result of unforeseen site conditions will be jointly approved by the City of Renton and the consultant prior to their implementation. 2.3 Monitoring Methodology The monitoring program will be conducted for a minimum period of five years, with reports submitted quarterly in the first year and annually thereafter to the City of Renton following plan implementation. Although the entire restoration area will be reviewed, permanent vegetation sampling plots or transects will be established to incorporate all of the representative plant communities. The same monitoring points will be re-visited each year with a record kept of all plant species found. Vegetation would be recorded on the basis of relative percent cover of the dominant species within the vegetative strata. Photo-points will be established from which photographs will be taken throughout the monitoring period. These photographs will document general appearance and progress in plant community establishment in the restoration areas. Review of the photos over time will provide a visual representation of the success of the mitigation plan. 2.4 Maintenance Plan Maintenance should be conducted on a routine, year round basis. Additional maintenance needs will be identified and addressed following the performance monitoring site visits. Contingency measures and remedial action on the site shall be implemented on an as-needed basis at the direction of the consultant or the owner. DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A John Kay March 4, 2024 Page 3 of 3 Routine removal and control of non-native and other invasive plants (e.g., Himalayan and evergreen blackberry, Japanese knotweed, purple loosestrife, English ivy, morning glory, thistle and creeping nightshade) shall be performed by manual means whenever possible. Undesirable and weedy exotic plant species shall be maintained at levels below 10% total cover within any given stratum at any time during the five- year monitoring period. Routine maintenance of planted trees shall be performed. Measures include resetting plants to proper grades and upright positions. Tall grasses shall be weeded at the base of plants to prevent engulfment. 2.5 Contingency Plan All dead plants will be replaced with the same species or an approved substitute species that meets the goal of the restoration plan. Plant material shall meet the same specifications as originally installed material. Replanting will not occur until after the reason for failure has been identified (e.g., moisture regime, poor plant stock, disease, shade/sun conditions, wildlife damage, etc.). Replanting shall be completed under the direction of the wetland consultant, City of Renton, or the owner. 2.6 As-built Plan Following completion of the restoration plan, an as-built plan and baseline assessment report for the restoration areas will be provided to the City of Renton. The plan and report will identify and describe any changes in grading, planting or other constructed features in relation to the original approved plan. The plan will also depict locations of photo-points and vegetation sampling points to be used during the performance monitoring period. The minimum 5-year mitigation monitoring period will not begin until after the City reviews and approves the as-built report and plan. All of the statements and conclusions presented in this report are accurate to the best of my knowledge. If you have any questions, please give me a call. Sincerely, ALTMANN OLIVER ASSOCIATES, LLC John Altmann Ecologist Attachment DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A MAPLE V A L L E Y H I G H W A Y - S R 1 6 9 15 2 N D A V E S E MAPLE V A L L E Y H I G H W A Y - S R 1 6 9 La n d s c a p e Ar c h i t e c t u r e AO A En v i r o n m e n t a l Pl a n n i n g & Of f i c e ( 4 2 5 ) 3 3 3 - 4 5 3 5 PO B o x 5 7 8 Ca r n a t i o n , W A 9 8 0 1 4 Fa x ( 4 2 5 ) 3 3 3 - 4 5 0 9 Al t m a n n O l i v e r A s s o c i a t e s , L L C By Da t e Re v i s i o n s Date Scale Sheet # Project# a Co p y r i g h t - A l t m a n n O l i v e r A s s o c i a t e s , L L C . 66 4 4 - M I T - 0 3 - 0 4 - 2 4 . d w g DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A MAPLE V A L L E Y H I G H W A Y - S R 1 6 9 15 2 N D A V E S E MAPLE V A L L E Y H I G H W A Y - S R 1 6 9 La n d s c a p e Ar c h i t e c t u r e AO A En v i r o n m e n t a l Pl a n n i n g & Of f i c e ( 4 2 5 ) 3 3 3 - 4 5 3 5 PO B o x 5 7 8 Ca r n a t i o n , W A 9 8 0 1 4 Fa x ( 4 2 5 ) 3 3 3 - 4 5 0 9 Al t m a n n O l i v e r A s s o c i a t e s , L L C By Da t e Re v i s i o n s Date Scale Sheet # Project# a Co p y r i g h t - A l t m a n n O l i v e r A s s o c i a t e s , L L C . 66 4 4 - M I T - 0 3 - 0 4 - 2 4 . d w g DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A MAPLE V A L L E Y H I G H W A Y - S R 1 6 9 15 2 N D A V E S E MAPLE V A L L E Y H I G H W A Y - S R 1 6 9 La n d s c a p e Ar c h i t e c t u r e AO A En v i r o n m e n t a l Pl a n n i n g & Of f i c e ( 4 2 5 ) 3 3 3 - 4 5 3 5 PO B o x 5 7 8 Ca r n a t i o n , W A 9 8 0 1 4 Fa x ( 4 2 5 ) 3 3 3 - 4 5 0 9 Al t m a n n O l i v e r A s s o c i a t e s , L L C By Da t e Re v i s i o n s Date Scale Sheet # Project# a Co p y r i g h t - A l t m a n n O l i v e r A s s o c i a t e s , L L C . 66 4 4 - M I T - 0 3 - 0 4 - 2 4 . d w g DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A La n d s c a p e Ar c h i t e c t u r e AO A En v i r o n m e n t a l Pl a n n i n g & Of f i c e ( 4 2 5 ) 3 3 3 - 4 5 3 5 PO B o x 5 7 8 Ca r n a t i o n , W A 9 8 0 1 4 Fa x ( 4 2 5 ) 3 3 3 - 4 5 0 9 Al t m a n n O l i v e r A s s o c i a t e s , L L C By Da t e Re v i s i o n s Date Scale Sheet # Project# a Co p y r i g h t - A l t m a n n O l i v e r A s s o c i a t e s , L L C . 66 4 4 - M I T - 0 3 - 0 4 - 2 4 . d w g DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A