Proposal for September 11, 2020 Downtown Flood Improvement Study Contact: Timothy Olson, P.E., CFM 651-724-0404 [email protected] 12224 Nicollet Avenue | Burnsville, MN 55337-1649 Ph: (952) 890-0509 | Fax: (952) 890-8065 | Bolton-Menk.com 12224 Nicollet Avenue Burnsville, MN 55337-1649 Ph: (952) 890-0509 Fax: (952) 890-8065 Bolton-Menk.com September 11, 2020 Dave Bennett, P.E. Public Works Director/City Engineer City of Northfield 801 Washington St. Northfield, MN 55057 RE: Proposal for Downtown Flood Improvement Study Dear Mr. Bennett: The City of Northfield has initiated the Downtown Flood Improvement Study to prepare for climate change impacts while also maintaining a safe community. Like you, Bolton & Menk, Inc. takes great pride in designing and managing projects that are sustainable and beautiful. Our approach to engineering services makes the City of Northfield’s priorities our priorities. We understand what needs to be accomplished for the successful completion of the Downtown Flood Improvement Study. We Know Northfield – Our team has completed a wide variety of stormwater management work in the City of Northfield, including a regional assessment of your drainage systems, comprehensive hydraulic modeling, and various flooding assessments. We have also examined FEMA certified floodplain modeling for several important tributary creeks and the Cannon River. Our intense knowledge of your systems ensures we can provide a quick and accurate analysis of your downtown area. Project Management – Reactive project management can create chaos, delays, and overruns. We will ensure that open lines of communication are maintained from project conception through closeout. Open communication will be implemented to clearly identify expectations of both Bolton & Menk and Northfield staff.Tim will lead reviews with the city to identify risks and ensure surprises don’t arise along the way. An Experienced Team – We have successfully completed numerous flood plain assessment and mitigation projects. We are experts in FEMA approved riverine modeling using innovative software and geospatial techniques; two-dimensional modeling applications that focus on break out flows and streambank stability; and FEMA certified flood control measures including levees and dams and the required internal drainage assessments. Our project team includes certified floodplain managers with more than 50 years of experience helping communities understand their risk of flooding and prepare for safe and sustainable flood protection. In continued service to the City of Northfield, we are excited at the opportunity to complete the Downtown Flood Improvement Study. I will personally serve as your lead client contact and project manager. Please contact me at 651-724-0404 or [email protected] if you have any questions regarding our proposal. Respectfully submitted, Bolton & Menk, Inc. Timothy Olson, P.E., CFM Project Manager Bolton & Menk is an equal opportunity employer. TABLE OF Project Understanding and Approach 3 Previous Experience 12 CONTENTS Project Team 15 References 23 Cost Proposal 24 PROJECT UNDERSTANDING AND APPROACH Section 1 Project Understanding and Approach 3 PROJECT UNDERSTANDING AND APPROACH Northfield’s Identity History of Flooding The Cannon River, a designated Wild and Scenic River, Northfield is situated approximately halfway between is a critical component to the City of Northfield’s the headwaters in Waterville and the confluence of environmental identity and gives the community a sense the Mississippi near Red Wing. The watershed area of place. Northfield has developed around the Cannon at the downstream end of Northfield is approximately River for nearly 150 years, starting as primarily an 940 square miles. Flow accumulation and, in turn, the agricultural community. As the downtown area expanded, potential for flooding for a watershed of this size can be the river was its focal point. The city has worked substantial, especially considering the Cannon River’s tirelessly to ensure residents and business owners feel relatively steep slope (2.3 feet of fall-per-mile). connected to the river and that it is integrated into the community. The city has also committed to protecting the Most recently, flooding in the Cannon River impacted Cannon River as a defining natural feature and enhance Northfield in 2010, 2016, and 2019. In September 2019, it when possible as development and redevelopment KSTP interviewed Northfield’s police chief who observed projects occur. “… some pretty interesting examples where it’s gone up four or five feet in less than six or seven hours”. This Unfortunately, river systems like the Cannon bring with description of flash flooding in the Cannon River makes it them the potential to flood. While the river is the identity a particularly sensitive issue for Northfield’s public safety. of Northfield and direct connectivity is an important goal, public safety and protection of critical infrastructure The increase in frequency of shorter duration and higher must be considered. Bolton & Menk is currently helping intensity storms is evident in Northfield. According to the the city with its commitment to understanding its last 10 years of precipitation record, there have been stormwater management system by developing regional • Approximately 11 rainfall events approaching 2.8 hydraulic modeling and summarizing potential drainage inches (a 2-year event) improvements. The next step in understanding the city’s • Approximately 3 rainfall events exceeding 4.2 inches overall safety is to consider improvements in critical river (a 10-year event) flooding areas. • One rainfall event approaching 6.2 inches (a 50-year event) According to FEMA’s Community Information System, Northfield has a total of 44 flood insurance policies totaling approximately $14,000,000 in coverage. Since 1978, the city had 29 insurance claims totaling approximately $2,700,000. Northfield is one of the most frequently impacted communities in Rice and Dakota Counties. Downtown Flood Improvement Study | City of Northfield, Minnesota S pring Cr eek Project Understanding and Approach 4 43 Legend St Olaf Ave Parcels Flood Prone Properties Zone AE Floodway 2nd St W 2nd St E Zone AE .2 PCT Annual Chance 3rd St W Ames Park 78 Union St 5th St W 6th St W Division St S Riverside Lions Park 8th St W Babcock Park Spring St S Poplar St Woodley St W 28 Commitment to Climate Adaptation and Resiliency Climate change has rapidly affected weather patterns, resulting in shorter duration, higher intensity storms, and the potential for more extreme and sudden flooding. By assessing rainfall events larger than the 100-year and/or assessing the systems drainage capacity under recently recorded, real-world rainfall events, flooding assessments can inform decisions about drainage capacity, property protection, critical site access, and public safety. By including climate adaptation and resiliency as long-term goals, the city’s comprehensive plan can be strengthened. The City of Northfield can rely on Bolton & Menk’s understanding of, and experience in, effective planning for a resilient community. The Metropolitan Council has also offered numerous strategies for developed areas to better integrate resiliency into comprehensive planning. The city can apply these concepts at the same or smaller scale because you already recognize that future development is contingent upon adaptation to changes in soil capacity, heat island effect, loss of watershed storage, increases in flooding, degradation of water quality, loss of wetland habitat, and many more. The downtown Cannon River corridor is certainly no exception. Downtown Flood Improvement Study | City of Northfield, Minnesota Project Understanding and Approach 5 Project Funding and Planning for for flood mitigation on the Cannon River and intend to leverage our knowledge of your system to help you work Future Phases through all three phases of this important project. The preliminary work completed in Phase 1 must consider constructability, which may require as much as a 30% design. Bolton & Menk is an extension of city Engaging and Informing the staff and we are ready to identify critical components of Community Phase 1 that can be leveraged into cost savings for Phases Bolton & Menk prides itself on successful public 2 and 3. We have helped numerous communities not only involvement processes. An engaged and informed develop lasting solutions to flooding, but apply for and public is the best way to garner project support and secure funding from the same source. We understand reduce conflict during implementation. We employ a what is needed during the planning phase to ensure consensus-building approach that blends the creativity positive outcomes in future phases. of project stakeholders with Bolton & Menk's professional expertise. This can be accomplished using Phase 2 involves preparing a benefit-cost analysis various tools, including that will require a maximized ratio of benefit to • Public information meetings/hearings, informal open cost. Therefore, a thorough cost assessment must be houses, and neighborhood gatherings—scheduled completed to ensure future projects are in a fundable for convenience to residents and neighborhood range. Phase 3 will include developing construction business owners and considering all applicable social plans and specifications. distancing policies • Brochures, newsletters, maps, and other graphics Our Partnership distributed by mail or email The City of Northfield and Bolton & Menk have