Skip to Content
Streetsblog California home
Streetsblog California home
Log In
Planning

Grassy Storm Drainage Can Be a Transportation Twofer, New Guide Shows

Indianapolis.

Few concepts are more important to modern street design than "traffic calming" — or, to use plainer language, "slowing down cars by putting large objects in the street."

But large objects (like flowerpots, pedestrian refuges, speed bumps or concrete domes) cost money. And if you want them both permanent and attractive, that's even pricier.

This is why on-street storm drainage can be a great deal for taxpayers and safe streets alike.

Slicing holes in the pavement and planting grass in them isn't cheap either. But in cities that get large bursts of rain, they're useful for preventing flooding and water pollution, and far cheaper than laying new pipes to carry stormwater away. So if your city's transportation department and its stormwater management department were to team up to put storm drainage in just the right places, it could be a very cost-efficient way to manage runoff while creating permanent, attractive separation between bike and car traffic.

A small storm drainage area can also create an excellent traffic diverter, reducing auto traffic on a bike-friendly side street.

berkeley diverter 600
Berkeley, California. Photo: Walk Eagle Rock

All of this is why it's nice to see the National Association of City Transportation Officials publishing an Urban Street Stormwater Guide, out next month:

Coming in June 2017, the Urban Street Stormwater Guide is a first-of-its-kind collaboration between city transportation, public works, and water departments to advance the discussion about how to design and construct sustainable streets. The Urban Street Stormwater Guide provides cities with national best practices for sustainable stormwater management in the public right-of-way.

NACTO has been a major force in advancing common-sense bike infrastructure. Hopefully it can help do the same with stormwater management, to everyone's benefit.

PlacesForBikes is a PeopleForBikes program to help U.S. communities build better biking, faster. You can follow them on Twitter or Facebook or sign up for their weekly news digest about building all-ages biking networks.

Stay in touch

Sign up for our free newsletter

More from Streetsblog California

StreetSmart 14.1 – What to look for from the 2026 Legislature

Our first nearly-comprehensive look at what is, and isn't, moving.

March 4, 2026

Wednesday’s Headlines

Is there more news happening these days, or am I getting better at finding it?

March 4, 2026

Three Theories About Why U.S. Car Crash Deaths Are Plummeting

Car crash deaths are down by 12 percent, a top group estimates — but why?

March 4, 2026

Dear Trump: the Future Belongs to the Efficient

Trump abandoned climate protection goals claiming that cheap fossil fuel helps consumers and the economy. A mobility-focused analysis shows that he is wrong: resource efficiency is the key to health, economic success and happiness.

March 3, 2026

New Draft CA High-Speed Rail Business Plan is LESS Costly than the 2022 Plan

Want a chance to really weigh-in on CAHSRA planning? Here's your once-every-four-years-chance.

March 3, 2026

Call to Action: Family Demands Justice for the Four Lives Taken at West Portal

The relatives of the family killed two years ago in West Portal by a reckless driver want the travesty to stop.

March 3, 2026
See all posts