Posting in Education
Keeping our planet's water clean starts in your own backyard.
A couple weekends ago I bundled up and took a boat tour of the Anacostia River with Jim Connolly, executive director of the Anacostia Watershed Society.
The Anacostia is not only Washington’s forgotten river, separating the city’s poorest section from the rest of D.C., but it’s heavily polluted. According to the Chesapeake Bay Foundation, the Anacostia is the area’s greatest source of pollution to the Bay, including millions of gallons of raw sewage. Today, there are a number of groups, including the Anacostia Watershed Society, that are working to clean up the river. But it’s still in bad shape.
One of the things that stuck with me after Connolly’s tour is that most Americans don’t know the definition of a watershed--which is clearly an obstacle in educating the public about clean water.
According to the Environmental Protection Agency, a watershed is the area of land where all the water that is under it or drains off it goes into the same place. The EPA says there are 2,110 watersheds in the continental United States. And we all live in a watershed, because when it rains, the water collects and eventually flows into a stream, river, lake, wetland or the ocean. Our daily actions within these watersheds—whether it’s pesticides on our front lawns, cigarette butts tossed on the sidewalk or tree removal for development—can be detrimental to our bodies of water.
One of the threats to the watershed is stormwater runoff. In urban areas like Washington, stormwater flows over paved roads and collects sediment, oil and metals that are then dumped into water bodies that are used for drinking and recreational activities. When soil is covered by pavement, it can’t absorb and filter stormwater like it would naturally.
So a group of researchers from Virginia Tech, Cornell University and the University of California at Davis recently released a manual that explains how to use trees in urban stormwater management systems to help protect water resources. The manual, Managing Stormwater for Urban Sustainability Using Trees and Structural Soils, is a novel system that uses structural soils (engineered tree soils) to detain stormwater and allow tree root growth in confined urban areas. The report says this approach more closely resembles the natural water cycle than traditional stormwater management techniques.
“This is a good introduction to the importance of having proper soil into which stormwater can be filtered,” Connolly wrote in an email. “It sounds like Virginia Tech has developed a way to enhance compacted soil so as to allow for perviousness while still supporting pavement and weight on top. If this works, it holds great promise for urban areas.”
This is just one small piece of the puzzle in cleaning up our waterways. The most important thing to understand is that no matter where we live—whether it’s on the coast or miles from a substantial body of water—we live in a watershed. The water that falls on our front porch and on our street and in our neighborhood will hit a body of water eventually.
Now you know what a watershed is. If you want to make a difference and aren’t sure how, start here.
Dec 6, 2009
This seems like a risky weather modification possibility...Creating even a small change in the natural convection of the earths temperature via oceans currents drastically affects life over the whole planet.. I would think a filter half way between the earth and sun could be controlled in the summer period to tweakpower balancethe heat absorption.. a disk rotating at a rate of 1 cycle every two years, with a controlled variable diameter to increase or lessen the heating effect..
Yes, National Geographic's "Great Rivers of the World" is just a few feet away. Nice pix showing the Youghioghany/Alleghany/Monongahela/ Kanawha/Muskingum/Scioto/Licking/Miami/Ohio/Illinois/Wabash/Kansas/ Missouri/Mississippi watershed, the Shenandoah/Opequon/Potomac watershed... There are other articles ZD has published here about permeable paving that does not have cracks and lumps the way interlocking paving stones do. It's more like asphalt that breaths. Probably the most notable discovery about water cycles is that some of the aquifers that we thought were primarily capillary action in micro-cracks and fine-grained particulate rocks and soils are actually massive, wide- open sub-terranean cave/tunnels... i.e. there's essentially zero filtration, and only a little settling of contaminants, and little time for enzyme action. Significant quantities of aspirin, birth control hormones, pesticides, etc. have been found in water supplies all across the USA.
Here's a good article on watershed in Maryland: http://baltimoresbesttreeservice.com/wordpress/?p=261
Permeable pavement is another approach that the EPA is studying for filtration of runoff. The freezing problem has apparently been solved, a porous pavement designed to minimize frost heaving has been used successfully in Norway.
You'd think the director of a watershed society (whatever one of those is) would use the word permeability instead of the non-word perviousness in a written communication.
Larry ... you start by giving off some incredulousness that sidewalks be made impermeable to water ... and then in the end you compared your back parking area with gaps inbetween the stones to what you would *not* want in a sidewalk with the "try pushing a baby buggy over such a bumpy terrain" .... re-read your post, you answer yourself. Now take out the baby buggy and replace it with an elderly person with a cane, a blind person with their cane, a person jogging, anyone that would need a smooth surface under their feet, to make sure they aren't tripping over water swollen sidewalks .... sidewalks that are generally flat, without sudden shifts in height or cracks that fill with other materials that could trip someone if they hit it the wrong way under their feet.
I can understand making roadways impermeable to water - if the temperature gets below freezing, any water inside it is going to swell up as ice and shatter the road. But do driveways and sidewalks have to be water impermeable as well? Sidewalks don't have to carry the weight load, nor drive ways be capable handling high speed traffic, that roadways do. Five or so years ago we expanded our parking in the rear of our house by adding a pavestone area adjacent to our driveway. To our surprise the gaps inbetween the stones quickly filled in with tiff, making the scene much more asthetically pleasing. The cars don't seem to mind when we park them on it. And the tiff helps capture and hold water that would otherwise just run off into the alley. While I wouldn't recommend such a treatment for sidewalks (try pushing a baby buggy over such a bumpy terrain) there are ways of putting in sidewalks that allow the water to percolate underneath it rather than just running off.
Nobody in a town near where I grew up knew what a watershed until they built 800 homes in it over a 3 year span. All were on septic systems and had huge golf course looking lawns. They polluted the towns water supply lake in less than 5 years after the first house was built. A $25 million water treatment plant was needed to provide clean drinking water, the town now has size restrictions on lawns and chemical fertilizers are banned in the watershed.
I mean.. if we're going to call this forum "pure genius"... then I expect a bit more than a superficial definition.
You know, a lot of rural places will have watershed ponds, either recreational or irrigational - where the land around drains to. There are degrees of "watersheds", in this sense, and this article seemed relatively superficial in explaining that. I have 3.25 acres on the top of a rise with a natural indendtation on it. I *own* my watershed. The real point is that "watershed" is a term that encompasses at least a couple different meanings and that those meanings have different application at different view elevations. (Individual properties, local municipalities, state, region... )
And I can even figure out how much volume in the resovior near my home needs to be let out to compensate for predicted precipitation.
From the Anacostia river it flows into the Potomac where it is used as drinking water by Maryland and Virginia. Waste water that is mostly treated then flows back into the Potomac where it is used again as drinking water by towns down steam. After this it all flows into the Chesapeake Bay along with untreated chicken sewage from the chicken farms on the Delmarva peninsula.