Des Moines Sewer Project Underscores Commitment To Infrastructure, Flood Control

November 2012, Vol. 67, No. 11

Flowing through the center of the downtown business district of Iowa’s vibrant capital city is the Des Moines River, a 525-mile-long tributary of the great Mississippi, and the longest river in the state.

Named for Iowa’s largest city, the river has long beckoned tourists to the downtown area for a variety of festivals, celebrations and entertainment venues. Now, a recent infrastructure improvement project promises to further enhance the downtown experience; affording visitors the opportunity to explore both banks of the river whether walking, jogging, biking, blading, or dining at one of several planned riverfront restaurants.

The Principal Riverwalk is a multi-year, downtown improvement initiative jointly funded by the City of Des Moines, the State of Iowa, Army Corps of Engineers, Federal Highway Administration and the Principal Financial Group, one of the city’s largest employers. When complete, the Principal Riverwalk will feature a 1.2-mile recreational trail connecting the east and west sides of downtown via two pedestrian bridges, and a 12-foot-wide multi-use trail along the balustrade at river level for joggers and bikers. Night-time lighting and security will turn the river loop into a 24/7 attraction as downtown Des Moines prepares to take on a new and exciting recreational role.

dmart1.jpg

Expansion-infrastructure equation
Planning officials agree that while city expansion projects -- especially those designed to attract tourists -- are exciting and beneficial for municipalities, new development can also place additional strains on existing infrastructures, especially storm-water and sanitary sewer services. The Des Moines Riverwalk project is no exception. Yet advance planning by city engineers and cooperative efforts among all parties afforded officials the opportunity to incorporate a much-needed upgrade to aging sewers, while addressing an ongoing threat posed by the river nearly every spring -- flooding.

After the historic flood of 1993, earthen berms and levees -- many of which failed to protect the downtown area -- were raised and reinforced. While the levee enhancements proved effective in containing the rising water within the river’s banks during a subsequent flood event in 2008, the aged, inadequate storm-water sewer system was unable to prevent flood waters from backing up into the downtown area again, surrounding many businesses. City officials focused on developing a solution. David Kamp, an engineer with the city and instrumental in the design of the project, explains the plan.