Take a look at what the snow melt this year did to the streambank protection on Newtonbrook Creek. Ouch.
In case you can’t tell from the picture, the creek flooded and wiped out the gabion baskets on the far bank, digging a new channel, turning the gabion baskets into an island and carving a new bluff. (Gabion baskets are large wire baskets full of rocks placed along river and stream banks to protect them from erosion.) Picturesque, sure, but not good. Trees are toppled or their roots exposed to air. Silt is washed into the river, changing the composition and warmth of the water and depriving it of oxygen, which kills fish and plants.
Incidentally, this is not “natural.”
Yes, snow has always melted (or, you know, when earth is cold enough to get snow–this may not last much longer, folks, so get your fill now), and when it melts it turns into water, and so water has to go somewhere, right? Right. So it always ends up in the rivers and creeks and they always flood in the spring, right?
No.
Because until recently, we hadn’t paved over every surface known to mankind. Soil is permeable; water drains into it. Asphalt and concrete are not permeable; water runs off of it. And into the storm sewers, and the rivers, causing them to flood and taking out the banks. And killing the plants and the fish. And wiping away topsoil that took hundreds or thousands of years to form. You’re with me, right? Paving everything=floods=not good.
I’ll assume you’re not about to rip up your driveway and replace it with gravel. Am I right? Right.
Other things you can do:
1. Disconnect your downspouts from the stormwater system.
2. Put rainwater collection barrels underneath your downspouts. Use the rainwater to water your lawn and garden in the summer. This is especially handy in areas prone to summer droughts and restrictions on water use. Alternatively, you can build a downspout bog garden, depending on how much space you have between your house and your property boundary.
3. Bug municipal stuff about making permeable pavers standard wherever applicable. Often useful for those huge parking lots surrounding big-box stores. Spare a moment to think of how much rain must run off of those parking lots, Dear Readers.
4. For the love of the gods, never, ever, ever, ever, ever put anything down a storm drain. I know you like salt. I know salt is easy and convenient during Canadian winters. Salt is a toxic substance. Just try, ok? And all the rest of it, too–it all ends up in the rivers–and the lakes–and while your little bit might not seem like much, all together, all those bits of chlorine from swimming pools and soap from car washing and bits of paint and cleansers and solvents make up a toxic mess. Stormwater runoff is more polluted than industrial discharge.
I’ll just say that again, shall I?
Stormwater runoff is more polluted than industrial discharge.
To sum up: Pavement: handy for rollerblading and baby carriages. Not a friend to Mother Earth. Use judiciously.
Here’s our “new” Newtonbrook Creek. Poor thing.
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*Post title taken from Neko Case’s recent cover of “Never turn your back on Mother Earth” on Middle Cyclone. Good album.
Zoopolis 
All good points you have made here. One thing I notice out here in the gravel and permeable forest floor is this. If you get a big snow melt or rain before the ground thaws, you get serious runoff even with nature’s checks and balances. And the result can look just like your photo. Me, I distrust gabions, retaining walls and all that sort of engineering because sooner or later it fails, in my experience. My point to add to yours would be leave the creek beds alone and don’t build close to them. If you do and your property disappears, you have only yourself to blame.