When Christian Park Elementary School decided to create a rain garden, it took six months for officials to figure out how to grant a permit for such a new-fangled project.

Guidelines unveiled Friday aim to cut that wait time from months to days by providing specific rules for rain gardens and other environmentally friendly projects that were once almost unheard of in Marion County.

Mayor Greg Ballard unveiled the new document Friday next to the school.

GO GREEN:Check out our news Web site dedicated to all things eco, green and environmentally in between.

A how-to manual for green infrastructure, the document takes much of the guesswork out of planning a green project and meeting the city’s requirements, two dilemmas that have slowed them in the past.

“If you want to design a rain garden, the document will tell you how to do it,” said Kren Haley, director of the city’s Office of Sustainability.

It will tell you what plants to use. It will tell you how much space you need to build a green roof and the load capacity the roof needs to hold 2 inches of water.

Developers will fill out a green checklist when they apply for permits through the Office of Code Enforcement. Any project incorporating infrastructure details from the Green Supplemental Document will be expedited for a permit so construction can begin sooner.

We hope that with sustainability in place, green infrastructure can be the norm and not the exception, said Rick Powers, director of the Office of Code Enforcement.

Ballard said green guidelines have support from local engineers and developers.

When we talked to engineers and architects, this was something that they wanted, Ballard said. They wanted to get going.

With that interest, he said making green projects more efficient to complete will dramatically increase the amount of such infrastructure in Indianapolis.