Storm sewers

Portland, like many cities, uses the sewer system to handle excess storm water runoff. Occasionally, this leads to the sewers overflowing into the Willamette River. Since this is bad and it rains fairly often here, the City of Portland embarked on a project nick-named “The Big Pipe”. So why am I telling you this? It’s a lead-up to explain why this incredible video at PAgent’s Progress is relevant.