Queen City Dam Hydrology Study

Project Summary:

Project Type:
Hydrologic Analysis

Owner:
ND State Water Commission

Overview:

The North Dakota State Water Commission retained the services of Apex Engineering in May of 2016 to study the hydrology of Queen City Dam. Queen City Dam was classified as a high hazard dam owned and maintained by the City of Dickinson. The purpose of the project was to provide a hydrologic analysis of the dam to determine dam safety and to preform subsequent dam break modeling.

Project Details:

The primary use of Queen City Dam is as a recreation facility. The principal spillway is an uncontrolled drop inlet. The riser structure is a 9 foot by 5-foot concrete box, with a headwall against the upstream face of the dam, resulting in a weir length of 23 feet.

Apex’s tasks included:

  • Developing a hydrologic model of the watershed above Queen City Dam using HEC-HMS
  • Simulating the inflow to the dam resulting from the Probable Maximum Precipitation.
  • Determining the percent of the PMP the dam can pass without overtopping.
  • Determining the capacity of the principal spillway, and evaluate the effect of high tail water on the principal spillway capacity.
  • Determining if the dam meets current spillway criteria for a class IV, high hazard dam.

The Queen City Dam study resulted in the following:

  • Urbanization has increased the drainage area from 3.82 mi2 to 4.13 mi2.
  • A survey of the crest of the dam, shows that most of the dam is lower than the design elevation.
  • The principal spillway does not meet the criteria for a Class IV dam as required by the North Dakota Dam Design Handbook.

The dam does not meet the auxiliary spillway criteria for a Class IV dam as required by the North Dakota Dam Design Handbook.

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