02-10-2021 Council Packet - Laserfiche WebLink

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STAFF REPORT TO: Mayor Keis and Members of the City Council FROM: Bill Dircks, Public Works Director Mark Kasma, City Engineer DATE: February 10, 2021 RE: Ryan Drive Road & Sanitary Sewer Improvements ACTION TO BE CONSIDERED: Motion to authorize Bolton & Menk to prepare a feasibility report for Ryan Drive road and sanitary sewer improvements. BACKGROUND: The Ramsey Washington Metro Watershed District (RWMWD) has spent the past few years assessing the entire District and looking for ways to reduce flooding and move water through the District with as little effect on private properties as possible. The new Atlas 14 storm water modeling resulted in a number of properties being added to the list of flood prone properties that weren’t previously considered flood prone. One of the most affected areas in the District is the area including North Star Estates manufactured housing park and Ryan Industrial Park. There has been flooding in both areas during past rain events and the potential for flooding is greater based on the new modeling and the type of rain events that have become more common. The RWMWD has determined that a larger culvert is needed underneath Ryan Drive in order to convey more water during events rather than flows backing up onto nearby properties and potentially flooding the structures. The existing culvert is a 30” reinforced concrete pipe. The RWMWD will be replacing it with a 6’ tall by 14’ wide box culvert. This will greatly increase the amount of water that can be conveyed under the road. The District will also be raising the grade of the road on either side of the pipe to prevent Ryan Drive from overtopping during extreme rain events. The improvements will increase the capacity of the culvert to a 50-to-75 year storm event. It currently has capacity for up to a 10-year event. The RWMWD has asked for the City’s participation in the project. Specifically, they have requested that the City pay for the road reconstruction portion of the project. The District will pay for all costs associated with the installation of the new box culvert as well as all mobilization costs. The current estimate for the road portion of the project is $200,000. That figure will be refined in the next few weeks as plans are brought to 95% completion. Three properties on the north side of Ryan Drive – 209 and 221Ryan Drive and 3151 Country Drive – do not currently have access to City sanitary sewer. The best available route in order to serve those properties is to connect to the sewer main on Ryan Lane and install a low pressure system that extends east to 3151 Ryan Drive. The three properties all have septic systems that