Friday, April 24, 2009
Saving trees in an incised urban stream.
Cara and I spent a couple of days doing a geomorphic analysis of an urban stream in O'Fallon, Missouri (just west of St. Louis) last week.
This one is deeply incised into a Missouri River Pleistocene terrace and is threatening some houses. But is has one thing going for it -- a very nice old growth riparian corridor.
We'll be working with the City and Reitz & Jens in St. Louis to stabilize this creek, most likely with grade control structures, and hope to save most if not all of those trees.
Notwithstanding its typically complex urban geomorphology, this one is tricky and will require experience and careful analysis and planning. Do the residents value the trees? Does the City's public works department value them? Can we site the structures to avoid damage to valuable trees?
I find a lot of confusion about how grade control works in river management and hope to post on grade control theory and practice here soon.