The city Community Development Department wants Juneau to develop rules to reduce the pollution and sediment that runs off land into streams and makes it difficult for fish to survive.
The Juneau Planning Commission last week unanimously adopted the department's recommendation that the city comprehensive plan address stormwater management. The recommendation is expected to go to the Juneau Assembly for consideration this fall. A stormwater management plan could lead to new rules for land use and building in the city, said Sylvia Kreel, a city planner.
Runoff from rain and melted snow on roads, parking lots and fertilized lawns carries with it soil, oil and chemicals that enter streams. The state has listed six Juneau creeks as polluted, mainly from sediment, under the federal Clean Water Act. Residents long have known that once-plentiful salmon runs in Duck and Jordan creeks virtually are gone. Fish eggs don't survive in the silty, oxygen-starved streams, biologists have said.
"One of the most important things we can do to clean up and restore those water bodies is to control stormwater," Carl Schrader, Southeast watersheds coordinator for the state Department of Environmental Conservation, told the commission.
Dave Hanna, an earth-moving contractor who chairs the Mendenhall Watershed Partnership, a citizens' group, said he saw fish disappear from a stream several years after nearby Back Loop Road was widened and paved.
"I've watched this scenario time and again in the area," he told the commission.
The ideal is to clean stormwater before it reaches storm drains and flows into streams, planner Kreel said.
The city has taken some steps in its stormwater system, and it applies some rules to developers on a case-by-case basis. But there are no city standards to manage stormwater, Kreel said.
Stormwater can be cleaned partially by filtering it through vegetation, such as grassy ditches alongside roads. Similarly, some city storm drains catch sediment in basins and separate oil and water.
A stormwater management plan is likely to affect private developments and land. It could include questions of how much of a developed parcel should be asphalt vs. vegetated land, or how much pollution can run off a private parcel.
The commission, in adopting the staff's recommendations, said the city should consider allowing developers to build more densely on their lots if they reduce pollution from runoff.
City land surveyor Terry Brenner, in written comments on Kreel's report, said the city should require engineered grading plans in some developments and the replanting of all slopes, along with barriers or filters to catch sediment.
The city shouldn't rush to pass hard-core standards, contractor Hanna cautioned. It should convene a panel of engineers, developers and city staff first, he said.
Commissioner Roger Allington, an engineer, agreed.
"Otherwise, I'm afraid we'll get a revolt and take two steps backward instead of one step forward," he told the commission.
Department staff recommended first mapping where stormwater gets into natural water bodies and inventorying the sediment load and pollutants there. The city also should inventory its stormwater system, maintain it and identify city land for sediment ponds and vegetated ditches, the staff report said.
It also calls for evaluating the city's development standards and creating standards for the amount of pollution and sediment that could flow off private land.