Source: City of Chicago

Today, outgoing Department of Transportation secretary Ray LaHood announced that his department would be offering a $100 million loan to Chicago for its riverwalk, a project Rahm Emanuel has touted as one of his mayoral legacies in development.

Construction is scheduled to begin in 2014 and end in 2016, though the Studio Gang-designed boathouses will be done this spring. (The loan isn't going to be finalized until this summer, but LaHood suggested it was "just a matter of crossing the Ts.")

The loan comes through the federal government's TIFIA (Transportation Infrastructure Finance and Innovation Act) Program. Currently, the interest rate is 3.10 percent on a 35-year loan. It's an old but underused program that LaHood massively expanded—up until this year, only $122 million was available for the program.

LaHood expanded that to $750 million this year, and $1 billion thereafter. That the money will be going to a riverwalk might also allay concerns that TIFIA will mostly be used to bankroll highway projects.

70 percent of the revenue to repay the city's loan will come from tour boat fees, which were rebid last year; the rest is expected to come from retail leasing, and perhaps a bit from advertising, though they said the city's "not heavily relying on it."

When you consider what Chicago can learn from other cities' waterfront projects, one of the points made by Phil Enquist (of the architecture firm Skidmore, Owings, and Merrill) is that a river is a good place to start civic renewal—as long as it's done properly. My fondest hope for the riverwalk is that it will eventually run beyond its planned six blocks (west from State, going around the bend to Lake Street). Right now, once you get south of River City (800 S. Wells), it's almost all under-developed industrial land out past the edges of the city.

A longer riverwalk could change that. Maybe $100 million in additional money will be enough to make it happen.