Agenda - Public Works Committee - 06/16/2015

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tend to sink into the wetland prior to being pulled back. The Cite did a project in 2012 where the boring machine was placed on upland in an existing easement extending to the street. The welding of the pipe was done on planking extended from an existing road. The jacked length was approximately 800 feet. The total project cost was $160,000. The Gibbon street project would require additional easements and restoration of all disturbed lawn surfaces. Option 2: This option looked at cleaning the existing county ditch that runs north of this development. This option is not feasible because it would require lowering the existing surface area of some wetlands up to 2 feet. This is not permitted under the Wetland Conservation Act. Option 3: The Miske's suggested using a different set of drainage and utility easements to run the water to the west. Evaluation of this route indicated that there are two high areas that would need to have pipe installed and that there is minimal elevation difference between the beginning and ending points. This route is not feasible. Option 4: Staff evaluated extending storm sewer pipe south in the Gibbon Street ROW then west in the 173rd Avenue right of way to provide drainage from the area. This appears to be feasible. The location and elevation of existing small utilities must be determined to better define the scope of this process. The normal water level of the existing wetland east of Gibbon Street should also be determined when evaluating the overall feasibility of this project. The pipe installation for this project is estimated at $275,000 - $300,000. This does not include acquisition of additional easements if needed. Funding Source: Funding would come from the Stormwater Utility Fee. Recommendation: Staff recommends further analysis of Option 4 to determine the overall feasibility the project. If the project were determined to be feasible it should be added to the Capital Improvement Plan so that it can be evaluated during the budget review process. Action: Motion to recommend the City Council consider ordering a feasibility study for Gibbon Street - 173rd Avenue Drainage concerns. Aerial Map Plan Profile Attachments Form Review Inbox Reviewed By Date Bruce Westby Bruce Westby 06/11/2015 01:30 PM Grant Riemer Grant Riemer 06/11/2015 02:01 PM Kurt Ulrich Jo Thieling 06/11/2015 03:30 PM Patrick Brama Patrick Brama 06/11/2015 04:00 PM Form Started By: Len Linton Started On: 06/09/2015 09:45 Ai l Final Approval Date: 06/11/2015