The leaves have taken a toll with all the wind and rain lately. In turn, the crinkly debris is riddled all over and the decision to collect or ignore is beginning to be internally debated. Whatever side of the fence you sit on in regard to handling the leaves, one place they most assuredly shouldn’t be is in the street along curbs.
Why? Because the end destination, come the next rain, is a nearby stormdrain leading to a waterway. What’s the big deal about this, you might ask? Let me explain.
When fall approaches, trees begin taking away nutrients from their leaves trying to prepare a cache of resources for the winter. However, not everything is taken out of the leaf and what remains is a mix of carbon, nitrogen and phosphorus.
If you’ve ever had a botany lesson, these three components are primary needs of plants (among a couple others) and in turn are beneficial to the plants below and the tree itself. Or just as well, your lawn especially if mulched down to small pieces that decompose easily. However, what’s good for the grass isn’t necessarily good elsewhere. Specifically, water.
I’ve mentioned this before, but it’s worth repeating: Nutrients and our waterways shouldn’t mix. Hence, when leaves make their entry through stormdrains, they concentrate nutrients near the outlets and cause havoc downstream. Particularly concerning is the phosphorus and nitrogen content which promotes algae blooms and takes very little to do so.
Of course, the analogy that an ecosystem is like a recipe should come to mind when thinking about this. After all, keeping proper proportions are key to success with both. Hence, when extra leaves (organic debris) start entering a system, it begins throwing things off.
Worth mentioning briefly too is the matting that leaves create blocking out nooks and crannies needed for aquatic life. When enough leaves pile up in slow flowing areas, insects that reside in the substrate below are cutoff as are spaces for young fish. Moreover, the leaf-mat can remain for a fair amount of time as breakdown is slowed when submerged in water.
Now, you might be wondering about trees along shores. Aren’t they a problem just like street trees? To put it concisely, the concern is in the concentration.
Trees along a shore are minimal compared to the number of trees across a whole town, if even a neighborhood. Hence, the amount of debris from shoreline trees is a small dose compared to the piles of leaves in a city. Keep in mind, too, that the trees along a shore are a part of that local system so what breaks down from their leaves originally came from nearby.
So what’s the point in saying all this? To bring attention to the likely pile of leaves cluttering your streets stormdrains. This is one of the best times of year to bother spending the few minutes it takes to clear leaves and debris from the curb or drain.
All the rain washes things away including these “freeriders." Therefore, spend a little time these next couple weekends keeping the crinkly mess out of our streets. If your so inclined, adopt a drain via our website, too.
Chris Gass is is the education and outreach coordinator at the Carlton Soil and Water Conservation District. Reach him at 218-384-3891 ext. 5. Information on the SWCD can be found on Facebook and at carltonswcd.org.