Updated at 3:38
Heavy rainfall early this morning in the north part of the Grand River watershed caused flooding downstream, including in the north end of Elmira where rising waters forced the closure of Arthur Street.
Significant flooding was seen in Floradale and points north, including Drayton and other parts of Mapleton Township.
The Grand River Conservation Authority reported that heavy rainfall in the north – more than 100 mm fell between 3 a.m. and 5 a.m. in the vicinity of Grand Valley – prompted the release of water from its upstream dams.
Woolwich Township officials had been notified of the GRCA’s plans, but the flooding was more significant than expected, said chief administrative officer David Brenneman, on site as flood waters rose in the vicinity of the Elmira Pet Products plant on Arthur Street North.
Nearby Bolender Park was completely under water before noon, as the flooding went well beyond the usual low areas of West Montrose and Three Bridges Road near St. Jacobs.
Portions of Floradale Road were washed out earlier in the morning, forcing its closure until repairs can be made, said Jared Puppe, Woolwich’s acting manager of engineering.
Region of Waterloo road crews made the decision before noon to close Arthur Street North at Church Street, with firefighters from Floradale called in to block the roadway at Reid Woods Drive.
“Staff have been monitoring other areas of the region but so far, this is the hardest hit area,” said Waterloo Region spokesperson Stacey Ferris of the Elmira situation.
The changing conditions and more rainfall left GRCA officials scrambling to provide updated information about the state of the watershed.
Water flows along the Canagagigue are at their highest level since 1974, the agency reports.
Levels in the GRCA’s reservoirs were already at the upper end of the operating capacity, noted spokesperson Cam Linwood. The large amount of rain in a short time span meant steps had to be taken.
Monitoring equipment at the Luther Marsh indicated 100 to 120 mm of rain fell in a two- to three-hour period early in the morning, “which is a record-level rainfall for the watershed at that location,” he added.
“Our reservoirs were already at the upper reaches of their storage capacity.”
Water was released from the Shand Dam (Belwood Lake) and Conestogo Dam (Conestogo Lake).
The reservoirs are part of the flood-control measures employed by the GRCA, with levels typically peaking around June 1 and falling as the year rolls along.
The rainfall to the north had the largest impact on the Grand and Conestogo rivers, said Linwood.
Water volumes and flows in the system, particularly the Conestogo River, were reminiscent of 1974, which saw significant flooding, particularly in Galt. Today, however, there is much more flood-control infrastructure in place, he noted.
UPDATE from the GRCA at 9:45 a.m.
“Flood co-ordinators in Woolwich township are requested to close the Three Bridges Road bridge upstream of St. Jacobs, and it should be expected that this bridge will remain closed through the weekend. Township staff are also asked to monitor Glasgow Street as flow may approach the capacity of that road later Friday. Flows on the Conestogo River are expected to peak later this afternoon or early evening and remain high through the weekend.”
“The trailer park in West Montrose will be flooded early Friday afternoon; the trailer park operator has been advised. Township staff are asked to monitoring conditions in the Village of West Montrose; it is expected that levels will peak later this evening through West Montrose.
“Flows will be high along the Canagagigue Creek through the Town of Elmira, however no flooding of structures is anticipated at this time. Flooding can be expected in the municipal park downstream of Arthur Street, municipal staff are asked to monitor and close this park as necessary.”
UPDATE from the GRCA at 1:24 p.m.:
“Flows in the Conestogo River are expected to reach 400 m3/s Friday afternoon. Flows of this magnitude have not been experienced since May 1974. Flood co-ordinators in Woolwich Township are asked to maintain closure of the Three Bridges bridge, upstream of St. Jacobs, and close Glasgow street bridge. Expect theses bridges will be closed through the weekend.
“The trailer park and portions of the Village of West Montrose will be flooded Friday afternoon. Flood co-ordinators in Woolwich Township are asked to warn residents as necessary. This magnitude of flooding through West Montrose was last experienced in May 2000.
“Flows will be high along the Canagagigue Creek through Elmira. Arthur Street and Bolender Park are flooded and crews are on-scene to maintain the closure. Flows of this magnitude were last experienced in June 2004. While not expected to increase further through Elmira, flows are expected to remain high through the weekend.”