36.14.303    NEW CONSTRUCTION - ENGINEERING DESIGN REPORT

(1) An engineering design report for construction of a new dam must include:

(a) a summary describing:

(i) the name of the proposed dam;

(ii) the name of the engineer;

(iii) the mailing address of the engineer;

(iv) the location of the proposed dam;

(v) the type, size, and height of the proposed dam;

(vi) the storage capacity and reservoir surface area for normal and maximum water surface elevation;

(vii) a general description of the dam and appurtenances;

(viii) maps showing the location of the structure that include county and state roads, and access to the site and the outline of the reservoir (Aerial photographs or USGS maps may be used) ;

(ix) an outlet discharge capacity rating table(s) referenced to reservoir elevations indicating the discharge that can be safely released;

(x) a rating table(s) indicating spillway discharge capacity referenced to reservoir elevations;

(xi) a table showing the reservoir area (in acres) and storage capacity (in acre-feet) for each foot of elevation from zero storage to the crest of the dam (Indicate the elevation of the dead storage, outlet elevation, and the elevation of the spillway(s) . All elevations shall be given in feet above mean sea level) ; and

(xii) photographs of the proposed site;

(b) a geology report giving a summary of the geological factors of the local area and dam foundation and the reservoir site, including:

(i) faults and fault history that may affect the dam or reservoir site;

(ii) seismicity of area and region; and

(iii) evaluation of reservoir perimeter for slide potential;

(c) a geotechnical report describing the investigation and evaluation and design of the foundation, abutments, embankment of the dam, and the borrow materials. Include an analysis to indicate that the dam, spillway, and appurtenances will be stable during construction, filling, and under all conditions of reservoir operations, including design earthquake loading;

(d) a hydrologic and hydraulic report that gives the design procedure(s) , calculations, and data for the reservoir and appurtenances;

(e) a drainage design report describing the data and evaluation of the seepage expected and the drainage and instrumentation design. The report must include criteria, design data, and references to show that seepage flow through the embankment, foundation, abutments, and appurtenant structures will be monitored and controlled so that no internal erosion will take place and so there will be no sloughing in the area where the seepage emerges;

(f) a quality control plan describing the extent and nature of the quality control during the proposed construction. The plan must include the responsibilities of the owner and engineer, the frequency of inspection, and any other items not already stated in the construction plans and specifications that are necessary to ensure compliance with the approved plans and specifications and construction of a safe dam;

(g) a plan for monitoring the performance of the dam. The plan must describe the assumptions, design considerations, and the proposed construction for the aspects of the dam to be monitored; and

(h) a report of other design data, assumptions, and

analysis data pertinent to individual dams and site conditions.

History: Sec. 85-15-110, MCA; IMP, Sec. 85-15-210, MCA; NEW, 1988 MAR p. 2489, Eff. 11/24/88.