Photo by Linda HeronPhoto Credit

Bannerman Dam, Onaping Lake – Replacement

Project Name:  Bannerman Control Dam Replacement
Project Location: Ulster Township, Sudbury District, ON
Proponent:  MNR
Contact:  J.L. Richard

There are literally thousands of older control dams in the province that are managed by MNR.  It is great to see them being repaired and upgraded, or even removed if they no longer serve any useful purpose.

The Bannerman is located in Ulster Township (North 46″ 51′ 1″, West 8’1^o 35′ 29^), at the southwest outlet of Onaping Lake. Onaping Lake is.approximately 62.16 km2124 mi2;in size with a watershed drainage area of 1015.28 km'(392 mi’). The lake is used as a reservoir. The drainage route through Bannerman dam is into Bannerman (Moncrieff) Creek and then into the Spanish River.

Bannerman dam is constructed of reinforced concrete. lt is has a single log sluiceway, which may contain up to 16 stop logs (7 doubles, 2 singles). The dam also has and eastand westweir. The east weir is 14.63 m (48 ft) in length; the west weir is 10.36 m (34 ft) in length.

The lake level, throughout the year, is presently maintained by following the cumulative rule curve from the 1993 Upper Spanish River Water Management Plan. The lake level is regulated using both the Bannerman dam and the Onaping dam. Generally under normal conditions, Onaping Lake will remain at full supply level (1306.5 to 1307 ft (398.2-398.4m asl) from Victoria Day weekend in May until Labour Day. Drawdown begins in September after Labour Day and discontinues when the lake obtains a level of 1304 ft (397.5 m asl) at Bannerman dam, or October 15th which ever occurs first.

Onaping Lake contains the Onaping Lake Conservation Reserve and the southern portion of the lake is part of an established canoe route to the Onaping River. There are over 200 cottages, along with a tourist lodge and marina. Fishing pressure is high, which the lake supporting species which include lake trout, walleye, whitefish, northern pike and perch.