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1539 Eleventh Ave. Helena, MT 59601
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Technical Notes

The Dam Safety Technical Notes are guidance manuals provided by the Montana Dam Safety Program to help engineers in their evaluation of high hazard dams throughout Montana. The methods found within these technical notes are accepted by the Montana Dam Safety Program and are common in engineering practice.

Technical Note 1 - Analysis of Spillway Capacity in Montana  *REVISED January 2019

Technical Note 1 (TN1) provides guidance to engineers engaged in the analysis and design of spillways for Montana high hazard dams. TN1 is intended for analyses related to high hazard dams regulated by the Montana Dam Safety Program, but the guidance provided can be used on other dams.

Technical Note 1 - References and Additional Information

Technical Note 2 - Loss of Life Determination for Spillway Capacity Analysis *REVISED January 2019

Montana spillway standards are risk based. As the potential for loss of life downstream of a dam increases, the spillway standard increases. Technical Note 2 (TN2) is provided to assist and guide engineers in estimating the potential loss of life downstream of Montana high hazard dams.

Technical Note 3
- Simplified Evacuation Mapping

Evacuation maps are a necessary component of emergency action plans. Technical Note 3 (TN3) describes Montana’s simplified cost effective procedures for developing evacuation maps.

Technical Note 4 - Chimney Filter/Drain Design and Construction Consideration

Technical Note 4 (TN4) is intended provide practical guidance on the design and construction of chimney filter and drainage features for embankment dams, particularly small embankment dams.

Technical Note 5 - Simplified Seismic Analysis Procedures for Montana Dams UPDATED 2020!

Technical Note 5 provides an updated step-by-step procedure for evaluating embankment dams for seismic stability.  Methods for determining liquefaction potential and estimating soil strengths are included.

Technical Note 6 - Downstream Hazard Classification Procedures for Montana Dams

Technical Note 6 documents methods and procedures used by the Montana Dam Safety program to conduct a downstream hazard determination.

Technical Note 7 - Guidelines for conducting a Potential Failure Mode Analysis for Montana Dams

Failure Mode Analysis is a useful tool for comprehensively looking at a dam. Results from a Failure Mode analysis can be used to direct future monitoring and identify repair priorities. A Failure Mode Analysis is not another engineering study….the dam owner/dam tender play a big role. Technical Note 7 describes how to conduct a cost effective simplified Failure Mode Analysis. Read how a Failure Mode Analysis can benefit you!

Technical Note 8 - Specifications Requirements for Dams

Technical Note 8 (TN8) is provided to assist and guide engineers in preparing construction specifications for Montana high hazard dams.

Technical Note 9 - Guidelines for Use of Pumps and Siphons for Reservoir Drawdown

Technical Note 9 (TN9) provides information to determine the best method to employ for reservoir drawdown. Both pumps and siphons effectively remove water from reservoirs and can provide the necessary increased capacity in emergency situations. Each site and event has unique circumstances which will determine the method best suited. This guidebook outlines a process using basic hydraulic and logistical considerations for determining the best method for reservoir drawdown. Part of this process includes outlining important factors to be used in decision making. Key topics for both pumps and siphons are explored in detail.

Association of State Dam Safety Officials Resource Database
ASDSO's Dam Safety Resource Database contains more than 12,000 entries that reference dam safety publications. These entries cover a wide variety of dam safety topics including technical and non-technical areas, history, best practices, regulations, news,and more. The entries also represent a variety of sources including federal and state departments, professional societies, research groups, industry news outlets, international organizations, and universities.