About a month ago, a frack-sand mining operation near Grantsburg, WI, spilled some fine-grained sediment from a settling pond into a tributary of the St. Croix River. Local news media covered the story, and more details, for example, can be found in the Pioneer Press story by Dennis Lien.
So what’s the big deal?
Well, there are standards regarding water turbidity, which means that as a society we’ve decided that we don’t like cloudy water, at least in some settings and at some levels. For a naturally clear-water system like the St. Croix, increasing turbidity would alter the food chain at all levels. Algal primary producers rely on sunlight blocked by turbidity. Sight-based predation at the top of the food change would be altered. Benthic (bottom-dwelling) organisms that depend on coarse substrates could be smothered by siltation. Especially in the St. Croix, one of the last refugia for freshwater endangered mussel species, we must be on guard against too much fine sediment. And finally, where does the sediment end up? It’s filling up not only man-made reservoirs but also treasured natural lakes, iconically Lake St. Croix and Lake Pepin. These lakes are filling in with fine-grained sediment at about 3X and 10X their natural rates, respectively. (How do we know? See work done by the Museum’s St. Croix Watershed Research Station.)
Hey, it’s only a little bit...
Or was it? How much is a little? A little here, a little there, and a little more from over there -- it starts to add up. All water in a watershed runs downhill to the river, efficiently carrying both particles and dissolved materials. The river ultimately sees it all: all the disturbances, however seemingly minor, throughout the watershed. Rivers die a death of a thousand cuts. We have enough difficulty trying to control nonpoint sources of sediment and other pollutants. Stopping discharge of fine-grained materials from a mining operation is eminently fixable. It’s the right thing to do. Fortunately, all parties seem in agreement on this, including the mining company, which has repaired its leaky dike.
Recently, I was sitting at my desk asking myself, “With the Mississippi River flood of 2010 past-peak, now what?” I mean, if I can’t obsessively check the latest crest predictions or watch the Science Museum's flood cam, what am I supposed to do with all my free time??
The whole purpose of River Life is to help people like me and you collaborate on issues of river sustainability. You say: “Hold up. What's ‘river sustainability’?” Good question! I asked Pat and Joanne myself and they said river sustainability is the study of how to continue urban living without harming the natural processes of rivers. Put another way, river sustainability is the study of maintaining harmony between human, aquatic, and terrestrial ecology. But don’t take my word for it, Pat speaks for himself about River Life in the Institute on the Environment’s, River Reflections:
Courtesy National Park Service
Did you know the Mississippi River is considered among the world’s largest watersheds? Me neither! A watershed is a geographic area within which all water flows into the same stream. The Mississippi River watershed covers about 40% of the continental United States. As part of River Life, this and other fascinating river facts will compose a River Atlas. This River Atlas is a work in progress set to debut fall 2010 and will eventually contain scientific data, videos, photos, art, and people’s stories about rivers.
The River Atlas section about people's river stories is called – no surprise here! – River Stories. Pat says river stories are important because they inspire people into action. While that’s certainly true, river stories are also simply fascinating in themselves. For example, did you know the upper landing area upstream from the Science Museum was known as “Little Italy” until the flood of 1952? After that, the city used the area for a scrap yard and then a parking lot. Today, it has been developed into high-rise apartments.
River Life’s dream for the Mississippi River is that people will learn how to engage the river in a mutually meaningful way. What does that really mean? It’s all about the river sustainability principle we talked about earlier: living with the river instead of against it. Pat’s example of a mutually meaningful river engagement is Harriet Island who’s flood-resistant social space is a great city amenity that also respects the natural process of flooding.
Courtesy St. Paul, Minnesota