A detail from a map of the scents of Gowanus, by Annie Barrett Studio. The design firm was the second place winner in Gowanus by Design's annual design competition. View Full Caption Annie Barrett Studio

GOWANUS — Turn left at the noxious chemical odor and then hang a right when you hit the cloud of sewage stink.

You can now give directions like that thanks to a map of Gowanus scents created for a design competition. An exhibit of the contest winners opens Wednesday and will be on view through March 5 at Site:Brooklyn gallery, 165 Seventh St. (between Second and Third avenues).

The competition was organized by Gowanus By Design, a nonprofit group of architects and designers with a mission to influence the rapidly changing neighborhood's development by advocating "better urban design," said executive director David Briggs.

To accomplish its goal, the group has hosted a series of design competitions. This year's contest, "Axis Civitas," invited entrants to create a Gowanus Atlas that maps conditions in the watershed surrounding the Gowanus Canal. Participants also had to design an "urban field station" where the atlas could be displayed and used by the public.

The contest winners, Nelson Byrd Woltz Landscape Architects and Weill Cornell Medical College, won $5,000 for their entry mapping the microbiome — a colony of tiny organisms — at the bottom of the polluted canal.

Second place went to Annie Barrett Studio for its map of Gowanus scents. The map catalogs the locations of a range of fragrances, from oil, sewage and exhaust to food and fresh air.

To create the map, Barrett sent a team of three people to tour the canal neighborhood on three different summer days, when the canal is particularly ripe. The scent surveyors sniffed out odors, then divided them into categories: negative manmade smells (sewage, chemicals and others), positive manmade smells (food, for example) and natural smells such as flowers.

The goal was to identify some of the "secondary impacts" the canal has on its surroundings, Barrett said.

"The biggest takeaway was not that surprising," Barrett said. "Where there's the biggest presence of industry, you have the most negative smells. As you move to where the neighborhood is starting to gentrify, you start smelling things like muffins or just more greenery."

Other contest entrants mapped conditions such as air quality, land ownership and the status of various cleanup efforts near the polluted waterway.

Briggs is now in the process of gathering funds to put the maps online and let the public add their own findings.

"The idea is that once all these things are lain on top of one another and synthesized, it will reveal something that wasn't apparent before," Briggs said. "It reveals a lot about the community that wasn’t obvious by straight-forward observation."