Loading...
HomeMy WebLinkAbout1A, Concept Plan of Bridge Over TH 10 ...... __ES Request for Council Action Prepared By: Kristine Giga Council Work Session Date: October 27, 2008 Concept Plan of Bridge over TH 10 connecting Old Highway 10 to North Snelling Budgeted Amount: $0 . Actual Amount: $5 million Funding Source: Not Identified Supporting Documents: 1. Memorandum dated October 23, 2008 from Civil Engineer Kristine Giga 2. Concept Plan submitted by resident ~ MEMORANDUM DATE: October 23, 2008 TO: Mayor and City Council Ron Moorse, City Administrator FROM: Kristine Giga, Civil Engineer SUBJECT: Concept Plan of Bridge over Highway 10 Connecting North Snelling/Old Highway 10 BACKGROUND The City Council received a concept plan from a resident for a roadway bridge to connect Old Highway 10 and North Snelling, and directed City staff to review the layout. With assistance from Bolton & Menk, a preliminary review has been completed and a preliminary cost estimate has been prepared. DISCUSSION/FINANCIAL IMPLICATIONS The primary benefit. of this crossing would be to provide an alternate crossing of Highway 10, which would most likely be used by those traveling from the northeast part of Arden Hills to Mounds View High School or Valentine Hills Elementary School. It may also be used as an alternate route to get to Bethel University. Given the current roadway system in Arden Hills, this crossing may be attractive to those wishing to avoid the CSAH 96/TH 10 intersection. However, once Ramsey County completes their improvements to the intersection, it will be easier and safer to cross at that location. If the crossing over TH 10 were to be constructed, it could be expected that traffic along North Snelling would increase. The Annual Average Daily Traffic (AADT) volumes for North Snelling and Old Highway 10 are listed below (2005 data): \\Metro-inet.us\ardenhills\PR&PW\Engineering\2008\W orkSessions\1 0-27 -08_ Memo_Bridge _Over_I O.doc Street Segment: North Snelling Old Highway 10 CSAH 96 to 1694 1694 to Valentine Lake Road: Valentine Lake Road to County Road E2: County Road E2 to County Road E/Lake Johanna Boulevard: AADT (vehicles per day) 1200 2750 2650 4700 8300 A field visit to the site identified several factors that need to be accounted for in reviewing the submitted concept plan: · Significant elevation difference on either side of TH 10 · Existing wetlands, floodplain, Round Lake discharge on west side of TH 10 · Existing power distribution poles on west side of TH 10 · Ownership of land to be used for the new road Road/Bridge construction: There is a difference in elevation of 20 feet from N.Snelling to Old Highway 10. However, the elevation of the bridge/roadway must meet clearance requirements over TH 10. The elevation of this new road at its highest point, over TH 10, would be 14 feet higher than N. Snelling, and 34 feet higher than Old Highway 10. A total length of 1,400 feet of road would be constructed; approximately half of this would be reconstructing existing roads to match into existing grades. This cost is estimated at $425,000. The cost for the bridge structure itself (200 feet long, 40 feet wide) is approximately $1 million. There would also be additional costs to construct the embankment and/or retaining walls for the road on the west side of TH 10 to connect it to Old Highway 10. These costs are difficult to project, as the amount of fill is dependent on the amount of retaining wall that may be constructed, however, for purposes of discussion, an amount of $1 million is being included. Existing wetlands/floodplain The area between TH 10 and Old Highway 10 has several low areas exhibiting wetland vegetation. The Federal Emergency Management Agency (FEMA) has the area identified as a flood zone on their maps; this area is also identified as the Round Lake Discharge Channel. Significant analysis would be required to ensure that drainage patterns are maintained. Any impacted wetlands would need to be mitigated as well. It is anticipated that a culvert or other structure would be required to maintain the drainage patterns through this area. This structure may be as complex or more complex as the bridge over TH 10; the cost estimate for this structure is $1 million. Existing power distribution poles There is an Xcel substation south of the area of discussion for the bridge over TH 10. Subsequently, there are two distribution lines that run to the north; one along Old Highway 10, one along TH 10. At least five (5) of these poles would be impacted as a result of bridge construction and the associated embankments. A cost of $100,000 per pole has been included in the estimate ($500,000 total). Right of way acquisition The area between Old Highway 10 and TH 10 is not City property; the land would need to be purchased to establish right-of-way for the road. Based on information available on Ramsey County GIS, the cost to acquire right-of-way has been estimated at $200,000. Summary The construction costs mentioned above total $4,125,000. Due to the complexity of the project and the number of agencies involved, project development and delivery is estimated to be an additiol1aI25%, or $1 million. The total estimated cost for construction of a bridge over TH 10 to connect Old Highway 10 to North Snelling is $5,125,000. CONCLUSION Staff is seeking direction from the City Council on additional action. Benefits of Concept Plan for N. Snellina I Old Hwv 10 1. Better way to connect current City to TCMP Development 2. N. Snelling has been upgraded to current 36' wide curb to curb street 3. Eastside homes (only 6) have large set back buffers from street 4. Church properties have large set back buffering to west side of street 5. City owns land at both sides of new bridge access points 6. A good current grade at Briarknoll / Old Hwy 10 7<< Old Snelling I Old 10 were identified as a regional trail corridor 8. Can better accommodate bike / foot traffic to high school from all parts of the City 9. Better connection to Long Lake Regional Park, Le. south side of Round Lake over Railroad Bridge 10. Best overall access to all parts of the city.