This course introduces the reader to the basic principles of identifying problems in existing earthen dams caused by animal activity. This manual summarizes FEMAs effort to provide a comprehensive survey of animal impacts on earthen dams across the United States. The results of the survey indicate that there is too often a wide gap between the known best practices of animal activity relative to dam safety and the perceived acceptable level of maintenance by many dam owners.  

In 1999, FEMA and the Association of State Dam Safety Officials (ASDSO) jointly conducted research on the national problem of animal intrusion damage to earthen dams. A joint workshop united dam owners, engineers, state and federal regulators, wildlife managers, foresters, and academia to create a comprehensive document to combat the growing problem of earthen dam damage and failures due to animal intrusion. The findings of the research indicate that while most states recognize animal intrusion as a problem, only a handful offer guidance on dams and wildlife management practices to the dam professionals and owners.    

  

Cumulatively, the states identified nuisance wildlife which were most likely to be a threat to dam safety. This manual discusses 23 species with regard to habitat, behavior, threat to dams, food habits, identifying characteristics, and management options. While the states are fully aware of the potential adverse impacts wildlife activity can have on earthen dams (such as failure), private dam owners and local dam operators are often not aware of potential problems, and thus may not conduct inspections with wildlife damage in mind.

This course demonstrates that some animal activity can potentially damage earthen dams beyond repair, and emphasizes the concept that delayed control and repair of animal activity usually results in increased total costs of repair. There are about 80,000 dams in the United States. Many of them are nearing the end of their expected lives. Proper maintenance and control of problems associated with animals can extend the useful life of many dams.

Awareness of the characteristics and seriousness of dam safety problems associated with animal impacts on earthen dams

A higher level of understanding of current damage control policies

Basic understanding of the habitat of common nuisance wildlife

Basic understanding of the range and behavior of common nuisance wildlife

Basic understanding of the habitat of common nuisance wildlife

Basic descriptions and range of common nuisance wildlife

Biological data for specific nuisance wildlife for use in indentifying which nuisance wildlife inhabits the dam

Methods of proper identification of common nuisance wildlife

State-of-practice guidance for remediation design considerations associated with damage associated with animal impacts on earthen dams

Rational and state-of-practice techniques and procedures for management of desirable animal activity on earthen dams

Useful statistics on dams damaged by animal activity

The different methods for repairing damage caused by animals

The recommended methods controlling different species of animals

How to recognize different species of animals and their activity

The use of construction methods for control of animal activity

The relationship between well compacted soil and animal activity

Some rules of thumb for analysis of dam safety conditions

Identification of the 5 safety inspection and evaluation zones

The pros and cons of regular maintenance versus long term remediation

The compounding affect of smaller animals attracting larger predators

The compounding physical and economic effects of delayed maintenance

Guidelines for estimating costs of maintenance and remediation

The critical need to maintain animal activity in a timely manner