The Long Point Region Conservation Authority (LPRCA) currently owns and operates thirteen dams
and water control structures within its watershed. Historically these structures were constructed for
flood control, low flow augmentation, recreation, erosion control, power generation and municipal
drinking water sources. Most of these structures were constructed in the 1960’s while others were
built over 100 years ago.
The Norwich Dam was originally constructed in the late 1960’s by the Big Otter Conservation
Authority approximately 103 km upstream from Lake Erie within the village of Norwich on Big Otter
Creek. In 1970, the dam came under the ownership of the LPRCA after the Big Creek and Big Otter
Conservation Authorities merged. Surrounding the dam and its reservoir is the Norwich Conservation
Area owned by LPRCA. The dam currently serves as a feature to the Norwich Conservation Area and
has historically provided low flow augmentation
The dam consists of earth embankments and concrete gravity dam structure that does not allow for
incremental adjustment of reservoir levels. An intake chamber and sluice gate are located on the
western wingwall that facilities lowering of water levels and provides low flow augmentation to Big
Otter Creek.
In the early 2000’s, LPRCA undertook dredging of the reservoir to remove accumulated sediment. The
reservoir level was lowered using the sluice gate and material was removed with a conventional
excavator. Dredging was primarily limited to the south portion of the reservoir near the embankment
and westerly limit. Dredgeate was placed on top of the dam’s embankments raising it approximately 1
m and partially covering the existing riprap armouring. Additional rip rap was added to the
embankment at the waterline after completion of the dredging.
The structure is approximately 50 years old and its condition is typical for a structure of its age. In
2014, Riggs Engineering undertook a close-up visual inspection of the Norwich Dam. The inspection
has identified concerns with the structure with a priority rating for follow-up action that has included
a Dam Safety Review. The Riggs Engineering inspection is attached to this Request for Proposal for
information. LPRCA is soliciting Request for Proposal (RFP) to undertake a Dam Safety Review of the
dam and its associated features including the reservoir, in accordance with the Technical Bulletins and
Best Management Practices by the Ministry of Natural Resources and Forestry (MNRF). The report
must include recommendations with cost estimates for all identified items requiring corrective
actions. The final report must explore alternatives for the structure including repair, replacement,
modifications, decommissioning, etc
The Dam Safety Review must be undertaken for the Norwich Dam in accordance with the Technical
Bulletins and Best Management Practices of the Lakes and Rivers Improvement Act (LRIA) as
administered by the MNRF for Dam Safety Reviews. The purpose of this study is to complete a
systematic review and evaluation of all aspects of the design, construction, maintenance, operation,
surveillance and all other factors affecting the dam’s safety. The study shall include the main water
control structure and all associated features such as the embankments, abutments, wingwalls, sluice
gate and reservoir.
