Numerous posts on various sites I have seen, including Facebook, news article comments, and many more, have given credit for the creation of unofficially named Lake Hampton to the new Tongue Creek Road extension, known to many as the George Groeneveld Bridge, or 498th Avenue. At first blush, that would make sense, given the map below.
However, people passing this judgement seem to have forgotten that this map is woefully incomplete. It's missing the road that goes past the cemetery (5th Street) and doesn't even show Tongue Creek Road, nor the new overpass.
It also doesn't show how far north Lake Hampton actually goes.
Observe an updated map of High River, with some annotations that I will explain. I recommend clicking on it to read the annotations.
The Highwood normally flows underneath Tongue Creek Road at the new George Groeneveld Bridge. The floodplain goes right up to those green lines, which is where 5th Avenue used to be before the overpass was built. For every flood previous to this one, the old 5th Street berm prevented the water from coming back. During the first day of the flood, this was still true. However, once it got north past Tongue Creek Road, the water levels in this year's flood were beyond anything we'd ever seen, and the banks were over-run.
The water spilled out into farmer's fields north of the Tongue Creek Road, and continued filling up, almost all the way out to Cargill. The only thing preventing it from flowing further east was Highway 2. Tongue Creek Road dips a bit before rising to the new overpass, and that is where the water spilled back. This is what the media meant when they said "the river had turned back on itself".
Between the new 5th Street and the new 20th Street Crossover, the land is low, and dips ultimately to just north of the Hamptons. When the water came over Tongue Creek Road, the terrain was already perfectly designed to become a lake. No developers had worked there yet, and so no blame can be laid on them for making the land too low. This low-lying land was always there. It was just that there had never been that much water before.
Observe the map below, circa 2002. Holy Spirit Academy, the school that remained underwater for almost a month in this year's flood, hadn't even been built yet. Neither had the Tongue Creek extension nor the new overpass.
5th Street was always there. The river always ran north. 498th Avenue was always there. Had we not built the extension to Tongue Creek Road, the area we now know as the Hamptons would still have become a lake. All those naysayers suggesting the new road caused all this are dead wrong.
Could we have seen this coming? Considering Lake Hampton eventually covered approximately 15 square miles of land (approximately the same size as Sylvan Lake), I'd say no.
Did those berms affect the flow, and make the creation of Lake Hampton more likely? Certainly a possibility. Where that berm ended is where the breach of the banks occurred that ended up resulting in half of a town sitting underwater for 3 weeks. I can't imagine that a berm is the best solution on its own anymore.
So what do we do instead of berms? I'll save that for the next post.
(For interest's sake, now that the Lake has been pumped out, some other lines of land have reappeared, particularly Tongue Creek Road, 20th Street, and a fenceline that once separated the Town of High River from the M.D. of the Foothills, somewhat north of the Hamptons. These lines of land have now effectively cut Lake Hampton into 4 bodies of water, which I have labelled Lake Hampton 1, 2, 3 and 4 in my annotated map)