Contact(s)
- Learn how to read these charts on our River and stream flows page.
- This river data can be downloaded from our Data Downloads page.
Provisional Data
Caution: Users of the GRCA's real-time data are cautioned to consider the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business.
The Grand River Conservation Authority assumes no responsibility for the correctness of the information contained in this website nor liability to any user of such information, regardless of the purpose.
Warning! River levels and flows can change rapidly.
Brochure
- Drayton: Preparing for Flooding - Published by the GRCA in co-operation with the Township of Mapleton and the OPP.
Critical flows
This chart will help you understand the significance of various flows levels. The chart shows the name of the gauge, the affected communities and various flow levels along with the significance of that flow level. Flows are measured in cubic metres per second, i.e. the amount of water flowing past a spot in one second.
| Gauge | Community | Flow (m3/s) | Significance |
| Upper Drayton / Drayton | Drayton | 0.1 | Normal summer low flow |
| 125 | Water at banks; low-lying areas flooded | ||
| 125 - 200 | Warning Zone 1 | ||
| 290 | Flooding behind Wood St. homes | ||
| 200 - 300 | Warning Zone 2 | ||
| 370 | Water crosses Wood St. | ||
| 300 - 400 | Warning Zone 3 | ||
| 388 | 1974 flood | ||
| 450 | Water crosses Main St. | ||
| 400 - 800 | Warning Zone 4 | ||
| Glen Allan | Glen Allan | 3 | Normal summer low flow |
| 50 | Water at banks; low-lying areas flooded | ||
| St. Jacobs | St. Jacobs | 4 | Normal summer low flow |
| 35 | Twp. Rd. 21 (Three Bridges Rd.) low-level bridge flooded | ||
| 150 | Water at banks; low-lying areas flooded | ||
| 595 | 1974 flood |
Location of flow gauges in the Conestogo River
