This article from Governing has some good ideas about water infrastructure.
In 2017, Columbus, Ohio, will finish building a new tunnel, measuring just under five miles, in its downtown area to create enough capacity to prevent excess stormwater from mingling with sanitary waste and being discharged into bodies of water without treatment. This $365 million project will effectively bring the city’s outmoded combined sewer overflow system into compliance with federal Environmental Protection Agency mandates. However, once this project is complete, the city would have been staring at an even bigger infrastructure need: a 28-mile system of tunnels to create enough capacity in its sanitary sewer system.
The problem primarily concerns residential properties. Old, cracked pipes leading from homes let excess stormwater seep into the sanitary system, and gutters that dump run-off into yards funnel more water into an already overwhelmed system. Sanitary sewer overflows occur, backing up into basements and streams. The standard solution addresses this issue simply by adding capacity: building bigger pipes underground to hold the water until it can be treated.
What made Columbus Mayor Michael B. Coleman take pause was that while the costs of building additional storage capacity were high, the benefits were markedly low and limited. The project would result in a new piece of infrastructure used maybe four or five days a year, and it would sit underground, literally, doing nothing for the landscape of the city and its citizens. The city got a delay from the Ohio EPA to design a better strategy.
The outcome of that effort is Blueprint Columbus, a more holistic approach to the city’s sanitary sewer overflow problems. We learned about Blueprint Columbus last month, when Coleman spoke at the National League of Cities’ Big Ideas for Cities event in Chicago. As a follow-up, we had a chance to speak with Susan Ashbrook and Dax Blake, the city’s assistant director of sustainability and its administrator of sewerage and drainage, about their cross-departmental approach. As Blake says, the goal of Blueprint Columbus is to “treat the cause, not the symptom.” This means working with residents to improve drainage from homes by installing sump pumps, redirecting roof run-off and repairing “laterals,” the pipes that carry wastewater from houses. And on a larger scale, it involves building a system of green infrastructure to keep excess stormwater from entering the sanitary system in the first place.
Retrieved June 5, 2014 from http://www.governing.com/blogs/bfc/gov-columbus-ohio-combined-sewer-overflow-green-water-infrastructure.html