Tagsewer

Philadelphia Water Department moves away from Deep Tunnel-style water management

West North points out that instead of spending $8 billion to build new sewage holding tanks throughout the city, the Philadelphia Water Department plans to conver impervious surfaces to pervious, natural surfaces. The American Society of Landscape Architects has more information on The Dirt:

The green infrastructure proposal would turn 1/3 of the city’s impervious asphalt surface, or 4,000 acres, into absorptive green spaces. The goal is to move from grey to green infrastructure. Grey infrastructure includes “man-made single purpose systems.” Green infrastructure is defined as “man-made structures that mimic natural systems.” As an example, networks of man-made wetlands, restored flood plains, or infiltration basins would all qualify as green infrastructure. The benefits of such systems include: evaporation, transpiration, enhanced water quality, reduced erosion / sedimentation, and restoration. Some grey / green infrastructure feature integrated systems that create hybrid detention ponds or holding tanks, which are designed to slow water’s release into stormwater management systems.

And, like Portland, Philadelphia is accomplishing more than just better stormwater management.

…the city is calling for a triple-bottom line approach, aiming for: more green spaces, improved public health, and more green jobs. [The Dirt]

Portland is building “Green Streets” that combine bicycle facilities with green infrastructure like bioswales inside curb extensions. This plan did not arise perhaps as altruistically as Philly’s (actually with a little controversy), but more as a way to build bicycle facilities with bioswale funding.

Meanwhile, the Deep Tunnel system in Chicago continues to expand. But it’s not all bad. The City of Chicago will showcase green infrastructure in a new streetscape in the Pilsen neighborhood.

Tribune points out why we need something better than Deep Tunnel

60 billion gallons of rain fell on Cook County on Friday night, according to the Metropolitan Water Reclamation District’s (MWRD) president Terrence O’Brien.

The world’s largest wastewater treatment plant just north of Navy Pier in downtown Chicago. One of two plants in the city limits. Photo by kendoman26.

That’s enough to fill 1.2 billion of these Suncast rain barrels*. The rain was too much for the Deep Tunnel – the underground network of  water reservoirs. They hold water runoff during storms before it goes to the water treatment plant for cleaning, after which it will flow into one of the water channels in and around Chicago. But the storms on Friday were too much – the MWRD had to release sewage into Lake Michigan because the reservoirs were full.

This in turn forced the Chicago Park District to close the beaches.

“All 109 miles of the Deep Tunnel system were filled during the storm, O’Brien said.”

We find ourselves in a situation similar to that of traffic congestion. Building new and wider roads doesn’t relieve traffic congestion. The same might be true for Deep Tunnel construction. Longer and wider tubes won’t reduce our water usage or how much stormwater is directed to the sewers (Chicago has a combined sewer, draining sewage from buildings and stormwater from the street). The Chicago Tribune article doesn’t exactly point out the solution, and it only hints at the problem: We get more water in our tunnel than we can handle.

The Chicago Harbor Lock separates the Chicago River from Lake Michigan was opened to allow the river to discharge its overflow into the lake. The water at Chicago’s magnificent beaches could have been contaminated so the Park District closed swimming at ALL beaches until at least Monday morning. Photo by Norma Fernandez.

Chicagoland needs a better stormwater management plan that incorporates sustainable best practices. We can start by encouraging landscaping that absorbs stormwater instead of acting like a slope towards the nearest drain. New streetscape projects can have bioswale planters. What other ideas are there to reduce the amount of runoff that has to be stored in hundreds of underground tunnels?

*The MWRD sells rain barrels to the public online for pickup. Rain barrels are just one part of a multi-pronged solution to stormwater management.

Norma Fernandez

© 2017 Steven Can Plan

Theme by Anders NorénUp ↑