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.
- Download a copy of the brochure Preparing for Flooding: A Guide for Residents of New Hamburg
- Download a copy of the brochure Preparing for Flooding: A Guide for Residents of Ayr
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.
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 |
| Nithburg | Nithburg | 0.2 | Normal summer low flow |
| 75 | Water at banks; low-lying areas flooded | ||
| Phillipsburg | Phillipsburg | 0.6 | Normal summer low flow |
| 108 | Water at banks; low-lying areas flooded | ||
| New Hamburg | New Hamburg | 1.5 | Normal summer low flow |
| 120 | Water at banks | ||
| 142 | Warning Zone 1 – water on fairgrounds | ||
| 175 | Warning Zone 2 | ||
| 300 | Warning Zone 3 | ||
| 500 | Warning Zone 4 | ||
| Ayr | Ayr | 2.6 | Normal summer low flow |
| 110 | Water at banks; low-lying areas flooded | ||
| 142 | Water on parking lots behind Northumberland St. | ||
| up to 200 | Warning Zone 1 | ||
| 226 | Water at rear doors behind Northumberland St. | ||
| 200 to 300 | Warning Zone 2 | ||
| 300 to 400 | Warning Zone 3 | ||
| 400 to 600 | Warning Zone 4 | ||
| 600 to 800 | Warning Zone 5 | ||
| Canning | 2.9 | Normal summer low flow | |
| 120 | Water at banks; low-lying areas flooded |
Location of flow gauges in the Nith River
