Title
A RESOLUTION AUTHORIZING AND DIRECTING THE CITY MANAGER TO ADVERTISE FOR BIDS FOR THE NORFOLK SOUTHERN RAILROAD CULVERT IMPROVEMENT PROJECT; AND DECLARING AN EMERGENCY.
Executive Summary: The Norfolk Southern Railroad Culvert Project will involve the installation a new 36" storm sewer system to provide for improved drainage from the area between SR 303 and Owen Brown Street on the west side of the Norfolk Southern Railroad Tracks.
Body
Legislative History
14-32; authorized a construction agreement and force account with Norfolk Southern.
Purpose & Explanation
In 2004, the City hired ARCADIS to perform a study on the railroad culvert following the 2003 flood. In 2009 a second study, performed by B &N, was requested to review the findings of the ARCADIS study and to determine how several new improvements may affect the proposed design. Both studies were conducted to determine if the existing 18" diameter culvert under the railroad tracks, which is undersized for the drainage area and is prone to blockages and continual maintenance per our Public Works staff, could be upsized. The studies identified what size culvert would effectively improve drainage from the twenty four (24) acre area located on the west side of the railroad embankment between SR 303 and Owen Brown Street. The analysis indicated that while a 24" diameter pipe would meet the criteria for design, the minimum culvert diameter allowed by Norfolk Southern is 36". In addition, the downstream storm sewer system was analyzed due to the increase in pipe size from 18" to 36". The studies show that after the improvement, additional capacity will remain in the existing downstream storm sewer systems. No downstream degradation is anticipated in the Brandywine Creek Tributary due to the overall large drainage area (1,100 acres) contributing to this section of Brandywine Creek Tributary versus the relatively small drainage area (24 acres) associated with this new culvert installation.
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