ONE HUNDRED YEAR FLOODPLAIN (SDDB)

It truly is amazing how practical smart our previous generations were. For example when you look carefully at aerial photographs you realize that the previous Stroh generation located their farm fields and farmhouse on the outskirts of Elmira (Hwy # 86)on the high ground just immediately above the one hundred year floodplain line as drawn by the Grand River Conservation Authority (GRCA). I believe that those location decisions were made many decades prior to the GRCA actually calculating and computing based upon elevations and calculations of water levels.

These decisions were also made many decades prior to any man made earthworks devised to mitigate flood damage. They were also obviously made decades before the Woolwich Dam was constructed in 1972. It was constructed both in summer and low flow periods to flush Uniroyal wastes down the Canagagigue Creek as well as to assist in reducing spring floods. It is however primarily an earthen dam albeit with considerable rock involved but nevertheless I believe that catastrophic dam failures are far more likely with earthen dams than with totally concrete dams.

I left some hints in Thursday's post here in the Advocate in regards to a berm on the Stroh property in a somewhat peculiar location. That location is on the immediate east side of the Stroh Drain and hence runs in a north-south line. The two recent March 2019 aerial photographs showed the floodplain line coming from north to south similar to the flow direction of the Creek on their site although then expanding in an easterly direction approximately at the 347.5 metres above sea level (masl) ground elevation contour. There are then two narrow southward sort of U shaped contours in the floodplain line with the second one being much longer and narrower than the first more northerly one. That second one is actually the berm on the east side of the Stroh Drain. Hence it is apparent from the aerial photographs that both the Stroh Drain and the berm were engineered to block the flow of flood waters in an eastward direction. The question is why.

Recall that in the first paragraph I indicated that the farm fields and the original farmhouse were located outside (i.e. higher elevation) than the 100 year floodplain line. Therefore why build a dual purpose drain, ditch and berm? It's a drain as it has successfully drained both surface and groundwater from both the Lanxess and Stroh property since approximately 1985. It is a ditch as it is approximately six feet deep and usually only has a few inches of water in the bottom flowing south and south-east back into the Canagagigue Creek. Lastly what are known as the dredge spoils (earth excavated from the ditch) are in fact a large berm that in conjunction with the ditch is stopping and redirecting eastward flowing creek waters in a southward direction. For me the only possible reason is to mitigate, reduce and redirect the force of the flooding Canagagigue Creek from scouring and eroding highly contaminated soils (Dioxins/furans/lindane/PCBs?) to the immediate east of the drain and ditch and berm.

From this point on I will refer to the Stroh Drain as the Stroh Drain, Ditch & Berm or SDDB.