Neighbors spearhead four new water-harvesting traffic-calming chicanes where two bicycle boulevards intersect

By Brad Lancaster,
DunbarSpringNeighborhoodForesters.org
HarvestingRainwater.com

In a continuing effort to enliven our neighborhood’s public space, and make it safer, while collaborating with the ecological systems upon which we all depend, we just installed four new water-harvesting traffic-calming chicanes/curb extensions at 9^th Avenue and University Blvd where our neighborhood’s two bicycle boulevards intersect.

Dunbar/Spring Neighborhood Foresters volunteers went door to door talking to neighbors with petitions to gauge support for the proposed project. With well over 90% of the neighbors within a one-block radius supporting it, Brad then applied for a grant, and designed and project managed the effort, while over 30 volunteers helped plant the chicanes, and adjoining neighbors stepped up to water the plantings to get them established.

Neighborhood efforts enhancing the larger community’s groundwater and surface waters

After one to three years of supplemental irrigation to get the young plants established, the multi-use native plantings will be watered solely by the rainfall and stormwater the chicanes passively harvest.

Once the new plantings are established, these installations will help indirectly and directly recharge our dwindling groundwater.

The established installations indirectly recharge the aquifer by not extracting water from it, so natural recharge of groundwater has a better chance of catching up to its unnatural extraction/pumping.

The established installations directly recharge the aquifer by passively harvesting more stormwater than their plantings (at mature size) will consume, so the surplus water that migrates down past the roots can eventually recharge the aquifer.

Rehydration leads to more shade, cooling, food, and more

This living green infrastructure depaves and replaces sections of non-living grey infrastructure by replacing excessive water-draining asphalt that increases the heat-island effect with water-absorbing transpiring life that increases the cool-island effect.

By reducing temperatures, these strategies also help reduce water loss to evaporation, which increase the more temperatures rise. Thus, this work enables beneficial moisture to linger longer, and cycle through more lives and potential.

See here for more on how this, and the soil-carbon-sponges works.

A living orchard, pharmacy, feed store, and flood control

Tucson Basin native plants were utilized as they are the best adapted to our soils, climate, and wildlife. And we emphasized native plants that also produce food, medicine, craft materials, and habitat for us, wildlife, and pets/livestock.

How we financed this

All was funded by an Inflation Reduction Act (IRA) urban forestry grant managed through the Arizona Department of Forestry and Fire Management. The Tucson Bird Alliance was our fiscal sponsor.

Protecting on-street parking, while calming traffic

The chicanes are strategically placed only on the entry and exit of the block, so they better slow traffic at the intersection where most accidents occur, and they push traffic out of the parking lane, and into the driving lane; thereby protecting, and encouraging, on-street parking. The more people park on the street, the more we further calm traffic, because the parked cars help narrow the street, and traffic speeds drop the more streets are narrowed.

Chicanes placed by the intersection, along with traffic circles in the intersection, are also advantageous because the intersections otherwise tend to be largest swaths of exposed, hot pavement.

Integrating with other traffic-calming strategies

We also got two new speed humps (not funded by the grant) on the blocks approaching the intersection to further slow traffic approaching, and within, the bicycle boulevards. Subsidized by the Ward 1 office and the city’s Speed Hump program, they cost $500 each, instead of $5,000 each. Brad Lancaster paid the $1,000 cost out of his own pocket, then solicited donations to help cover the cost.

Another two speed humps were installed on the other two blocks approaching the intersection as part of the city of Tucson’s bicycle boulevard improvements.

And in May, Brad Lancaster worked with the City of Tucson to get a speed hump installed between two existing chicanes on 4th St between Stone Ave and Ash Avenue where neighbors had been experiencing excessive traffic speeds and accidents.

All this makes a big difference in helping slow speeding cut-through traffic, and making conditions much safer for the many kids (and adults and pets) bicycling and walking this route to and from Davis Elementary, Tucson High, El Grupo Youth Cycling and many other connected destinations.

Striving to evolve city-wide practices as we develop and evolve our own

We’ve aimed to develop and evolve city-wide practices with this latest round of water-harvesting traffic-calming chicanes. They build on designs and installations done in 2010, which were funded by a Pima County Neighborhood Reinvestment grant.

Evolutions in the latest phase include:

• Designs that use significantly less rock.

• Ensuring that the top of all rock in the basin is at least two inches lower than the stormwater inlets and outlets to the chicanes (boulders are the exception as their purpose is to keep cars out of the chicanes).
This way the rock does NOT accumulate sediment like baffle structures used to create point bars.

• Expanding the stormwater harvesting capacity of the chicanes.
The chicanes built in 2010 are 14 inches deep—6 inches deeper than the typical 8-inch-deep chicanes—and they work great.
We designed and built the new chicanes based on that proven success.

• Placing chicanes on BOTH sides of the street, across from one another, to more effectively narrow and shade the street (along with the associated vegetation) to better calm traffic.

• Prioritizing the placement of the chicanes where we have adjoining neighbors committed to help steward them.
This dramatically increases the likelihood of success without creating more burden on overstretched and under-resourced city departments.

• Training neighbors on how to better steward their neighborhood green infrastructure. So, they can better steward this green infrastructure and show others how to do the same.

How we begin

Such neighbor-led traffic calming begins by seeing if neighbors want this, by going door to door with petitions and maps of the proposed traffic-calming locations, and talking with neighbors living on the street within a one-block radius of the proposed traffic calming. At least 60% of those most affected must sign their approval for the project to move forward (we got well over 90% approval). We strive to converse with 100% of those most affected when passing around the petitions. Whether or not they approve of the proposed strategies, this is a great opportunity to better get to know your neighbors, their hopes and concerns, and build community. Based on feedback we get in this phase, can then modify the proposed plans. Jesse Soto and Jozett Keena with the city of Tucson transportation department’s neighborhood traffic management program create the petitions upon request

Brad is currently working with neighborhood volunteers living on our east-west streets—those with the highest volume of cut-through traffic (1^st Street, 2^nd Street, University Blvd, 4^th Street, and 5^th Street)—as they pass around petitions to see if their neighbors want more traffic calming on those streets, what type, and if they’d be willing to help steward installations such as water-harvesting traffic-calming round-a-bouts or chicanes.

Simultaneously we called bluestake at 811 to mark all underground utilities, to ensure there are no underground utility conflicts in any of the proposed water-harvesting traffic-calming strategy locations.

If there is the neighbor support, city approval, and adjoining neighbors who commit to stewarding the installations, we then seek funding.

Street-side planting of rain and native food forests—a parallel effort

This is the 29^th year of the Dunbar/Spring Neighborhood Foresters’ annual Rain & Native Food Forest Planting program, which since 1996, has resulted in neighbors working together to plant, and care for, over 1,800 native trees, thousands of understory plants, and the harvest of over one million gallons of stormwater per year (to provide the free irrigation) in our neighborhood’s public rights-of-ways. This has resulted in many tree-shaded, rain-hydrated, & cooler walkways and street-sides that used to be sun-blasted, dehydrated, & hotter.

Regularly check out the Events page at NeighborhoodForesters.org for the next community planting day of our public rain garden installations, our twice per year hands-on pruning and tree care workshops, stewarding parties to help care for (and get help caring for) this growing neighborhood forest, and sign up to get rain garden installations adjoining your residence or business.

How you can help:

• Sign up on the Contact page at NeighborhoodForesters.org to stay informed of our various efforts.

• Join Neighborhood Foresters and become a steward of the plants, basins, chicanes, and/or traffic circle(s) near you (we partner, and coordinate, with the City of Tucson’s Storm to Shade program in this maintenance).
Email Brad at NeighborhoodForesters@gmail.com to sign up, and get training and support as an official steward…

• We’ll then show, and help, you to identify and remove invasive weeds; while identifying and helping preserve and encourage beneficial plants and wildflowers. We’ll provide you with native restoration and seasonal wildflower seed. Learn how to properly prune and mulch. And we’ll help you organize, and help lead, stewarding parties with other volunteers on your block—a great way to get to know your neighbors and improve our community.

• Keep our public pathways welcoming and accessible for all by maintaining the city’s required minimum 7-foot height and 5-foot width of clearance (from overhanging branches, path-side plants, path edging, rock, parked cars, etc) for all public paths;

• Also keep our public paths clear of gravel that impedes the elderly, the very young, and those on wheels.

• Identify where you’d like to create new basins and plantings along, or within, the street, enlarge existing basins, and sign up for the installations.

• Donate to help support our efforts

A guide on how to make such water-harvesting traffic-calming in your neighborhood

Coming soon! It will be posted at NeighborhoodForesters.org

For more info on these and many other water harvesting strategies and efforts

Check out the full-color editions of Brad’s books, Rainwater Harvesting for Drylands and Beyond, available at deep discount, direct from Brad at HarvestingRainwater.com.

Spanish edition coming summer 2025!

More photos