[ Jacobs Dam ]

Project :

  
Jacobs Dam Site Study
Location :
Dent County, Missouri
Date :
 
 
 

Ms. Reitha Jacobs owns land on a tributary of Nelson Branch, about 7 miles northeast of Salem, Missouri. She proposes to construct a dam to create a lake that will be used for recreation, fishing, wildlife preservation and the production of hydro power for a nearby house. It is Ms. Jacobs intent to construct a dam that is less than 35 feet in height. Concerns about the project include the site geology, the valley topography (which will result in shallow areas around the lake), and the projected cost.

WILSON HYDRO was retained to perform an evaluation of the site to determine its suitability for the construction of an earth dam and reservoir.
WILSON HYDRO teamed with J. Larry Hubbard, consulting engineer, to complete the site evaluation for Ms. Jacobs. Site visits were made and an engineering survey was conducted to layout the preferred dam centerline and emergency spillway location. Test pits were excavated to evaluate potential borrow sites, the depth to bedrock in the core trench and the hydraulic gradient in the valley. Recommendations and quantity estimates were prepared to construct a dam ranging in height from 25 feet to 45 feet. It was determined that the dam would be a significant hazard structure (Class II) with a watershed size of 484 acres. The presence of springs within the basin, combined with the watershed size, indicated that the dam could produce about 5 kW of sustained power, depending on its height.

Based on the results of the site investigation, it was determined that the site was suitable for the construction of an earth dam. However, to produce a reservoir with sufficient size (30 acres) to meet the various needs of the owner, the proposed dam would have to be at least 40 feet in height. The total amount of fill needed to construct the dam was approximately 75,000 cubic yards.