Yet, maintaining and improving municipal stormwater systems is an important economic and environmental issue. Encouragingly, Grand Haven is poised to take a step forward as the City Council considers Grand Haven’s first Storm Water Design and Management ordinance.
A quick stormwater refresher:
As land has developed and open spaces have filled with hard, impervious surfaces, precipitation increasingly causes soil erosion, water pollution and flooding. Salt, hydrocarbons, fertilizers, pesticides, pathogens, trash and other miscellaneous “junk” from our roads, roofs, parking lots, etc., is picked up by rain and other forms of precipitation.
This stormwater runoff does not slowly infiltrate back into the ground, as it would have pre-development, and recharge the groundwater supply. Instead, it flows through the watershed at faster speeds, higher temperatures and in larger volumes than the ecosystem evolved to handle. In Grand Haven, it is carried toward the Grand River and Lake Michigan.
Grand Haven’s proposed stormwater ordinance will apply to all new developments and redevelopments that disturb 1 acre or more — not including mobile homes, farm operations and existing developments.
William Hunter, director of the city’s Department of Public Works, confirms that the increase in hard surfaces can have a detrimental effect on aquatic systems.
“Heightened levels of impervious cover have been associated with stream warming and loss of aquatic biodiversity in urban areas,” he said.
Stormwater isn’t sexy, but managing it innovatively can be!
While stormwater is frequently out-of-site/out-of-mind, many of its environmentally friendly best management practices (BMPs) are visible and attractive. Hunter said: “Innovative site designs that reduce imperviousness and smaller-scale low- impact development (LID) practices dispersed throughout a site are excellent ways to achieve the goals of reducing flows and improving water quality.”
An assortment of BMPs and LID tools are available to accomplish this: rain gardens, preserved green space, floating walkways and natural shorelines are just a few. In fact, Grand Haven can already boast a “green” roof on the Community Center, a grass swale along Jackson Avenue and native landscaping along Beacon Boulevard.
In order to improve water quality, mitigate flooding and encourage the best management practices like those described above, the proposed ordinance creates stormwater management zones with varying levels of water protection. For example, Zone A requires a higher level of protection and would likely include more sensitive areas and those converting from rural land use to urban. Zone A would provide flood control detention and runoff treatment for large rain events. Zone B might include areas discharging into rivers and larger streams, where full channel protection is necessary, but flooding protection less so.
The proposed ordinance also begins to address soil erosion and sedimentation. New developments and redevelopments significantly disturbing the earth’s surface are required to “control” soils eroding from the site or discharging into a public street or right of way, floodplains, streams and other water bodies. The ordinance is designed to “maintain the integrity of stream channels” for both biological and drainage purposes.
It is important to note that deterioration of watercourses can also damage culverts, roads, bridges, utilities and other infrastructure.
In addition to the localized impact of erosion from stormwater runoff is the aggregate impact. For example, last year, the U.S. Army Corps of Engineers contracted out $540,000 worth of dredging in the Grand Haven channel. Rivers have always carried sediment, and lake levels have an immense affect on the need for dredging. But it is also true that both the quantity and contamination of sediment loading on Spring Lake, the Grand River and Lake Michigan are exacerbated by stormwater runoff.
With rain in the near-term forecast, frozen ground and an incredible snow-pack stormwater runoff could bring flooding, erosion and other problems during the spring thaw. On Saturday, April 19, Grand Haven-area residents will have an opportunity during the Grand River Greenup (grandrivergreenup.com) to directly respond to stormwater runoff by removing litter from the banks of the Grand River and Spring Lake.
However, an ounce of prevention is worth a pound of cure, and we should be doing all that we can to prevent runoff in the first place. By passing and robustly implementing the city’s first stormwater ordinance, Grand Haven will take an important step forward in accomplishing just that.
— By Nicholas Occhipinti, the policy and community activism director for the West Michigan Environmental Action Council