Until last week, Jenny Sippel and Jon Colville wouldn't let 4-year-old Dylan play in the patched, worn and bumpy alley behind their house in the Standish-Ericsson neighborhood of south Minneapolis.

That was before their newly laid alley was finished, featuring a network of concrete pavers that allowed Thursday night's downpour to soak into the ground rather than run off the pavement.

"We are excited for Dylan because he likes to play out in the area," Sippel said.

The family is one of five households along 21st Avenue S. that joined hands with a local nonprofit and a couple of government agencies to get their alley — which they jointly own — replaced with a permeable alley, one of the first of its kind in the Twin Cities.

The eco-friendly alley is designed to capture rainwater and allow it to seep into the earth. While unique here, the innovative approach to paving has been used in other cities such as Chicago, which began installing permeable alleys more than a decade ago as part of its Green Alleys Program.

"Rather than stormwater running off the alleyway into the storm drain and directly into the closest lake, river or stream, the runoff soaks into the pavers, infiltrating into the ground and being cleaned naturally by the soil," said Laura Scholl, associate director of Metro Blooms, a Minneapolis-based nonprofit that develops environmentally friendly landscaping.

The project began in 2015 when Lori Fewer, one of the five homeowners, bumped into a Metro Blooms stall at the Monarch Festival on Lake Nokomis.

She and her neighbors had just discovered that they — not the city — owned their alley and they wanted to beautify it. Metro Blooms staffers suggested making the alley surface permeable.

"I spoke with other neighbors and they agreed," said Fewer, a nurse practitioner who lives with her spouse, daughter and dog.

Meeting after meeting followed, with funding for the $100,000 project emerging as an issue. The group eventually got support from the Minnehaha Creek Watershed District and Hennepin County, each of which contributed $40,000. The families pitched in the remaining $20,000.

"The moment we came to know that Hennepin County will contribute, we were clear that the idea would be rolling soon," said Kristina Fjellman, another neighbor, who works as a marketing manager.

Before the new surface was laid two weeks ago, the privately owned alley — between 21st and 22nd avenues and north of 39th Street — was in poor shape. Its slope caused stormwater to pool at the dead-end near a garage. It wasn't used much; neighbors generally parked on the street.

Earlier this month, the old alley surface was replaced with 1,530 square feet of the PaveDrain system, which uses gray interlocking blocks with arched chambers and a porous layer of stones beneath to capture and filter rain and melting snow.

Metro Blooms, with technical assistance from the University of Minnesota's St. Anthony Falls Laboratory, installed a trench drain/rain gauge monitoring system to check how much rainwater went down the alley before the new surface and after. Water data on the new alley will be collected for another year.

"Now it looks beautiful," Fewer said, pointing out how three of the five neighbors have already improved their own driveways off the alley.

The permeable alley initiative met four goals at once: reducing flooding problems, enhancing the look of the alley and adjacent driveways, improving water quality by capturing the runoff, and producing data on water flow before and after installation.

And thanks to the project, the alley owners — who are responsible for maintaining it — know each other better, too. They will hold a grand opening for their new alley on June 19.