MISSOULA — Citing the heat produced by the Missoula Public Library's roof and the need to address polluting stormwater runoff, members of the City Council on Wednesday approved a $149,000 contract to turn the rock roof into a green island.
To aid in the project, the city landed a $1 million grant from the Western Montana Conservation Commission's green stormwater infrastructure program. The grant requires a 25% match, with the Library Foundation providing $70,000, and the Missoula Redevelopment Agency (MRA) and Missoula County each contributing roughly $75,000 over the next two fiscal years.
“Because stormwater needs to be managed in urban environments to protect water quality and prevent flooding, we have a lot of regulations that oversee our work,” said Tracy Campbell, superintendent of the city's stormwater utility. “Our guiding mission is to protect public health and safety, natural resources, waterways, and our aquifer.”
Converting the relatively new rock roof into a “living roof” will help the city comply with stormwater regulations and various control measures. It will also provide pollinator habitat and be open to the public.
Campbell said the project will serve as a demonstration of ways to mitigate urban heating while also addressing water quality. The project looks to apply natural processes to treat what otherwise would serve as polluting runoff.
“By incorporating green stormwater infrastructure in a public building, we're aiming to increase awareness by adopting this type of management,” Campbell said. “The library makes an exceptional site for demonstrating green stormwater infrastructure to a very wide audience.”
Measurements taken last summer found that the rock ballast roof was often far warmer than the ambient air. Temperatures taken on the roof last April exceeded 120 degrees, Campbell said. On a 91-degree day later in summer, the roof reached 164 degrees.
The roof conversion was approved on a 7-2 vote, and while the project may cost more up front, council member Kristen Jordan said the investment was worth it.
“The benefits both financially and environmentally are something the city should continue to look at,” Jordan said.
Council members Bob Campbell and Sandra Vasecka voted in opposition.
“I do not believe this is an appropriate use of MRA money,” Campbell said. “I'm not averse to the project at all, but I don't believe this is an appropriate use of MRA money for this purpose.”
