It’s no secret that our infrastructure is experiencing more frequent problems from increased demand and extreme weather changes. By 2030, the world is going to spend an estimated $10 trillion on repairing and expanding infrastructure to address aging and demand, according to an estimate by McKinsey & Company.
While cities have earmarked funds to address the aging infrastructure, many are finding it hard to keep up with the demand of repairing pipes before problems arise. Today, a new trend is emerging for cities to utilize natural infrastructure to improve their water resources. Through the use of natural lands, working landscapes, soil and vegetation systems, some cities have built green and gray infrastructure that has helped improve overall infrastructure, water conservation and ground pollution.
Research shows that deep roots and multi-layered tree canopies of healthy forests are helping to purify water, regulate flow and storm water runoff and reduce the impact of flooding and droughts. These efforts might sound costly, but they are proving to reduce capital costs, lower maintenance costs and reduce treatment costs while also generating social and environmental benefits.
These natural efforts can’t fix the problem alone. When used in conjunction with engineered solutions, communities can protect and improve their ecosystems, reduce their carbon footprints, improve local economies and even save money.
A recent article from the World Resources Institute highlights cities that have embraced natural infrastructure with great results.
The City of Philadelphia was challenged with combined sewer overflows during storms. The city estimated the economic benefits associated from green infrastructure efforts would range from $1.94 billion to $4.45 billion, compared to just $0.06 billion to $0.14 billion from gray infrastructure, or the human-engineered solutions.
The city adopted the “Green City, Clean Waters” plan in 2011 to reduce storm water pollution through greening public spaces by creating a living landscape that slows, filters and consumes rainfall. When complete, the city estimates an 85% reduction in storm water and sewage pollution entering the waterways.
More than 75,000 people reside in the City of Medford, which discharges wastewater into the Rouge River. When the discharge from the city exceeded the maximum temperature load requirements, the city had to find an alternative.
The city investigated lagoon storage for discharge later in the year, as well as mechanical chillers and restoring vegetation along the rivers and streams to provide shading along the river. An economic analysis found that restoring the vegetation was three times more cost-effective than mechanical chillers for reducing thermal loads into the river and would provide additional benefits to local wildlife and water filtration.
The city plans to work with 100 landowners through the “Freshwater Trust” to restore 30 miles of stream banks at a cost of $8 million; however, the natural approach was still $8 million cheaper than lagoon storage and $12 million less than installing mechanical chillers, which also emit greenhouse gases.
These are just two examples of what cities around the nation are doing. Check out how New York and São Paulo, Brazil, are utilizing natural infrastructure to improve their communities at http://www.wri.org/blog/2015/10/cities-can-save-money-investing-natural-infrastructure-water.