Wildwood and Pittock Dams – More than just Flood Control
If you are a regular visitor to Fanshawe, Wildwood, or Pittock Conservation Area, you may have seen one of the reservoirs being used for its flood control role – storing water to reduce downstream flooding. Did you know that Wildwood and Pittock Reservoirs have a second, equally important, role: increasing downstream flows in the summer and fall?
The Upper Thames River Conservation Authority (UTRCA) stores water in Wildwood and Pittock Reservoirs to reduce downstream flooding due to snowmelt or rain, and uses that water to supplement downstream flows in the summer and fall, to support water quality and aquatic habitat.
The UTRCA’s engineers follow an annual operating cycle for Wildwood and Pittock Dams. The reservoirs are at their lowest (winter holding level) at the start of the year. The low reservoirs have room to manage winter floods and to store runoff from snowmelt and winter/spring rains, which is used to fill the reservoirs to their summer conservation level.
Wildwood Reservoir close to winter holding level.
Beginning usually in late June, the water stored in the reservoirs is gradually released, increasing flows downstream to benefit water quality and aquatic habitat. Wildwood Reservoir augments flows in Trout Creek downstream to St. Marys, and in the North Thames River from St. Marys downstream to London. Pittock Reservoir supplements flows in the South Thames River from Woodstock downstream to London.
Wildwood Reservoir at summer conservation level.
The reservoirs are slowly lowered throughout the summer and fall by releasing more water downstream than is coming into them from upstream. By early December, both reservoirs have been drawn down to their winter holding level, which maintains sufficient water for aquatic habitat while increasing flood storage for fall and winter floods. This brings the operating season full cycle, ready for whatever the next year brings.
Read more about how UTRCA operates its flood control structures. Flood Control Structures – Upper Thames River Conservation Authority