DATE: December 15, 2016
TO: Board of Mayor and Aldermen
FROM: Eric Stuckey, City Administrator
Paul Holzen, Director of Engineering/City Engineer
Jonathan Marston, Assistant Director of Engineering
William Banks, Staff Engineer
SUBJECT: title
Consideration of Resolution 2016-94, A Resolution to Approve the Final Design and to Authorize Property Acquisition and Construction of the 100-Block Battle Avenue Drainage Improvements Project (12/15/16 CIC 4-0)
body
Purpose
The purpose of this memo is to provide information to the Franklin Board of Mayor and Aldermen (BOMA) concerning Resolution 2016-94, which approves the final design and authorizes property acquisition and construction for the 100 Block Battle Avenue Drainage Improvements Project.
Background
On December 9, 2014, the BOMA approved Resolution 2014, which formally approved the preliminary design of the 100 Block Battle Avenue Drainage Improvements Project and authorized staff to proceed to complete right-of-way (ROW) acquisition, final design and construction. That design was based upon the following criteria:
• Expansion of Existing Detention Basin -
There is one significant man-made detention basin, within the 100-Block of Battle Avenue, for a self-storage facility located at 110 Fairground Street. The existing basin does not have an outlet or outlet control structure. Storm water runoff stored in the existing basin is pumped to an existing storm sewer system at the intersection of Fairground Street and Columbia Avenue. The recommended alternative for improving drainage and flooding within the 100 block area of Battle Avenue includes expansion of the existing pond approximately 100 feet to the north which increases available storage to contain storm water runoff. With the pond expanded, a new pump system will be installed. Drawdown after a rainfall event will be regulated to ensure that capacity of the existing storm water system where the water is pumped is not exceeded. The expanded detention pond would be placed on an isolated parcel of land located behind 1408 Columbia Avenue and 107 Battle Avenue.
• Additional storage volume of the proposed expanded detention basin would provide enough volume to reduce flooding and drainage issues at all five residences in the 100-Block of Battle Avenue during the 100-year storm event. Any storm event larger than a 100-year storm, like the May 2010 Flood, may still have some flooding impacts to properties in the area. This is mainly because of the downstream stormwater system, and its capacity constraints.
• Stormwater area drains will be installed at the low points near 113 and 114 Battle Avenue to eliminate the roadway ponding / hydroplaning concern. This system will be piped between 113 and 115 Battle Avenue to the City owned alley behind these properties. The Stormwater will then continue being piped along the alley to the expanded detention pond.
• The backyards of 109 through 115 may be slightly re-graded so stormwater ponding can drain towards the City alley. A more-defined grass swale will be created in the alley that will properly convey the backyard stormwater to the expanded detention pond. To properly install this system, some existing trees and landscaping will be removed and replaced with new trees and landscaping.
• Property Acquisition will encompass multiple drainage easements and temporary construction easements. The City hopes these will be donated because of the improvements we are making to their properties.
It is important to note that the depth of the expanded detention will need to be 15 to 17 feet to provide storage for the 100-year storm.
After detailed drainage design and geotechnical study phases, the Engineering Department is now ready to begin the property acquisition phase (e.g. ROW and easements) for the project. Resolution No. 2016-94 approves the final design and authorizes property acquisition and construction for this project
Financial Impact
Property acquisition will encompass multiple drainage easements and temporary construction easements. Because the improvements directly benefit the affected properties, staff will request donation of the required easements. The vacant parcel required for the expanded detention pond will need to be purchased in its entirety. Condemnation proceedings may be needed to acquire this parcel if negotiations with the owner reach an impasse. The current estimated costs for the project are:
• Sub-total Construction Line Items $1,078,401.40
• 10% Contingency $108,000.00
Total Estimated Constr. Cost $1,186,401.40
• Property Acquisition Costs $150,000.00
• CEI (7%) $75,488.10
• Surveys & Easement Preparation $7,000.00
PROJECT TOTAL $1,418,889.50
Total project funding included as a part of FY2017 Stormwater Budget under Capital; 89410 Drainage; Various is $1,500,000.00. Unfortunately, staff does not anticipate utilizing a large portion of these funds in the current fiscal year. Therefore, portions of the project costs will come from the FY2018 Stormwater Budget under Capital; 89410 Drainage; Various.
Recommendationrec
Staff recommends approval of Resolution No. 2016-94.