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HomeMy WebLinkAboutCorrespondence Miscellaneous 3/28/2008 oregon bridge delivery partners~ , March 28, 2008 Ms, Heather O'Donnell Planning and Development Department City of Eugene 99 West lOth Avenue Eugene, OR 97401 Re: 1-5 Willamette Bridge Project Dear Ms, O'Donnell, The supplemental items you requested on March 25, 2008 for the 1-5 Willamette Bridge Project Metro Plan and Refinement Plan amendment applications (MA 07-3 and RA 08-1 respectively) are attached. The items you requested and a summary of the information provided is included in Table I. Please contact me at (503) 423-3785 or corrinne.humnhreviaJ,hdrinc.com or James Gregory at (503) 423-3706 or iames,l!Tegorvfalhdrinc.com if additional information is needed or if you have any questions, ' Sincerely, ~ ,." ~!": . 4~i ,. . Corrinne Humphrey, AICP Oregon Bridge Delivery Partners 1001 SW 5th Avenue 1 Suite 1800 I Portland, OR 97204 ph: 503.423.37061 fax 503,423.3737 email: corrinne.humnhrevlal.hdrinc.com Attachment: . Metro Plan Policies C 32 Narrative I" . Willakenzie Area Plan Policy Neighborhood DesigJ) Element Policy I Narrative . ,Laurel Hill Plan Land Use and Future Urban Desigri Policy 6 Narrative oregon bridge delivery partners1165 Union Street NE Salem,,'OR 97301 \ ' ' Date Received MAR 2 8 2008 Planner: 8J Page 1 of 2 " ,I I J p ~~"-'-'''~'''c;.'"''''''''''7~~'~"","'-' - ""~"'",~.,:;7~~-- ;, Table I; Suj,xplelnelllal Requests and Responses Comment ~ Landslides, slopes, erosion, etc are discussed further under metro plan policy C.32, Laurel Hill Valley Policy C.6, W AP neighborhood design element policy I, , Response"? ,,,\ Metro Plan policy C.32 is, addressed in the attachment to this letter. Willakenzie Area Plan Policy Neighborhood Design Element P~jicy 1 was addressed in the revised Metro Plan Amendment Applic~tion written statement submitted on February I, 2008 and is addressed in the attachment 'to this letter. Laurel Hill Plan Land Use and Future Urban Design Policy 6 was addressed in the revised Metro Plan Amendment Application written statement submitted on Feoru.ryl, 2008, The policy is also addressed in the attachlAent to this letter with supplemental text added, i' :..,... .}S~. j;"~:'l I. ~';. . Date Received MAR 2 8 2008 oregon bridge delivery partners1165 Union Street NE Salem, OR 97301 , Planner: BJ Page 2 of 2 '\{: Metro Plan C. Environmental Resources Element Natural Hazards (Goal 7) . ~ Policy C32 Local governments shall require site-specific soil surveys and geoLogic studies where potential probLems exist, Whim problems are identified, local governments shall require special design considerations and constructil!n measures be taken to offset the soil and geologic constraints present, to protect Life an(j property, public investments, and environmentally-sensitive areas, ODOT understands that under Natural Hazards Policy C.32, local governments will require site-specific soil surveys and geologic studies where potential problems exist, and that where problems are identified, they will require that special design considerations and construction measures be taken to offset the soil and geologic constraints present .in order to protect life and property, public investments, imd enviro~entally sensitive areas. I In 2003, ODOT drilled ten borings on either side of the river as a part of a geotechnical investigation related to the temporary detour bridge over the Willamette River. Three of the borings were drilled north ofthe river, including one for the Canoe Canal Bridge and the remaining seven were drilled to the south. Additionally', a Geological Resource report was developed for the project, which contains the following information. Geological resources in the project area consist of fill m~terial, alluvium; and bedrock. The processes affecting these materials are anthropoge,nic, such as excavation and grading, and natural, such as landslides, erosion, and e'arthquakes. Since there is an existing bridge, impacts to geological resources would consist of relatively minor changes in topography, minor settlement of near-surface materials, possible increased erosion, minor changes to the river flow regime and re'lated sediment transport, and potential changes in slope stability (e.g., slopes may become unstable as a result of vegetation removal). These impacts would occur as a result of excavation, placement of structures and fills, and clearing and grading, 'I' \ . Impacts related to construction would be limited to tempo,rary, localized changes to the river flow regime; stability of partially constructed slopes; erosion; and resultant sedimentation, Landslides could be caused by constructiori activities that create unstable slopes or as a result of improper slope stabilization follo~ing construction. The highest risk due to landslide would be slope failure .into the Willamette River, Considering the low height of the riverbank, such a failure would be limite~ to a small area relative to the width of the river. It could result in temporary damming of a portion of the river and the release of silt, which could temporarily adversely affect aquatic life and water quality in the Willamette River. ' All earthwork would require temporary erosion protection and sediment control until permanent protection is established. Earthwork along the ri'ferbanks shot}~~eceived oregon bridge delivery partners ,; 1165 Union Street NE Salem, 9R 97301 pageu1 of 3 MAR ~ 0 2008 Planner: BJ engineering controls to prevent movement of loose soil into the river: Finished slopes should be constructed under the guidance of an engineer to prevent over-steepening of the slopes ahd to anchor loose material. In-water 'work should include construction of cofferdams or similar Best Management Practices (BMP) to control releases of sediment . into the river. In-water work in shallow areas should be completed during summer months when little or no water is flowing in these areas, The project would have no permanent effects on geological resources. Based on the earthquake hazard, geotechnical investigations will be completed during design to determine the best method to seat foundations, piers, and bents to reduce effects related to earthquakes (e.g., lateral spread, liquefaction). In addition, slopes will be constructed in a manner that reduces the potential for erosion or small landslides. For instance, to fit the bridges and roadway approaches within the existing, permanent ODOT right-of-way, relatively steep side slopes and retaining walls would be require,d for the portion of fill that supports 1-5 between the Canoe Canal and Willamette River bridges. Additionally, the new, bridges would meet current safety and design standards, resulting in bridges that are constructed using techniques that meet current seismic standards. Willakenzie Area Plan Neighborhood Design Element - Waterways Policy 1 Significant wetLand, riparian, water and upland sites in the Wi/lakenzie area shall be protected from encroachment and degradation in order to retain their important functions related to jishand wildlife habitat, flood control, sedimentation and erosion control, water-quality control, and groundwater pollution control. Affected riparian areas and fish and wildlife habitat in the Willakenzie area can and will be protected through compliance with the permitting requirements contained in the Eugene development ,code for proposed development in the green way and, in areas subject to Statewide Goal 5. The City of Eugene can impose approval conditions as it deems necessary to protect these resources to the extent practicable, consistent with the need to provide it new 1-5 Willamette River crossing relevant to the Transportation Element policies identified above. Flood control, sedimentation and erosion control, and water-quality and groundwater pollution control can be achieved through these same permitting processes, through the issuance of permits to allow development in the floodway or floodplain, and by requiring ODOT to construct the new bridges and demolish the decommissioned and detour bridges using Best Management Practices, Laurel Hill Plan I. Land Use and Future Urban Design Policy 6 The Laurel Hill PLan supports the South Hill' Study standard~, In general, aLteration of the Land contours shall be minimized to retain views of natural features and oregon bridge delivery partners 1165 Union Street NE Salem, OR 97301 Date aeGeived'" MAR 2 8 2008 " " r Planner: BJ;' retain as much of the forested atmosphere as possible, Aside from purely aesthetic considerations, these hillsides demand care in development because the topsoil is thin and the water runoff is rapid. Proposed developments shall respect the above considerations, The Valley hillside policy applies to all land with an average slope, from toe to crest, of 15 percent or greater, (A I5-percent slope is one in which the land rises 15 feet per 100 horizontal feet.) a, Jf, in the opinion of the responsibLe City official, an adverse conservation or geological condition exists upon a parceL of Land proposed for a subdivision, or before any major hillside clearing, excavation, filling or construction is contemplated, the requirements of the Uniform Building Code, Chapter 70, Excavation and Grading, and those sections of the code relative to foundation design may be invoked. b, ConsiderabLe latitude shall be allowed the developer in the shaping, depth, and required street frontages of lots where it is necessary to preserve the terrain. , ' ODOT understands that under Laurel Hill Land Use and Urban Design Policy 6, on average slopes of 15 percent or greater, alterations to the landscape generally shall be minimized as much as possible to retain views and the forested atmosphere. On all affected lands, whether or not 15 percent slope or greater, ODOT intends to minimize alterations and restore vegetation to the extent possible. ODOT also understands that if in the opinion of the responsible City of Eugene engineer, an adverse conservation or geological condition exists before any major clearing, excavation, filling or construction is contemplated, the City may invoke provisions of the Uniform Building Code Chapter 70 and those sections of the code relative to foundation design, Project improvements would occur within the existing ODOT rightcof-way. The vegetation removed will be limited to the minimum area necessary for construction and, staging activities. Following construction, cleared areas will be revegetated and returned to existing conditions to the extent practicable. Grading would be limited to minimum area necessary. Areas affected by construction activities would be restored following construction, See response to Metro Plan Policy C.32. oregon bridge delivery partners 1165 Union Street NE Salem, OR 97301 , \1 . ,," b~ .~ f /' Date aeGeived MAR 2 8 2008 Planner: BJ