ORS 540.443 Definitions for ORS 540.443 to 540.491

As used in ORS 540.443 to 540.491:

“Construct” means:

To build a new dam;

To modify dam height; or

To make modifications to a dam that:

Do not include modifying dam height, performing maintenance actions or removing a dam;

Have a potential impact on the safe functioning of the dam; and

Are to an extent that the modified dam structures no longer conform to the original design.

“Dam” means:

A hydraulic structure built above the natural ground gradeline that is used to impound water or wastewater; and

Appurtenant structures on or adjacent to hydraulic structures described in paragraph (a) of this subsection that affect the stability of, or the control of water through or away from, the hydraulic structure.

“Dam failure” means a rapid, sudden and uncontrolled release of water or wastewater due to loss of dam integrity.

“Emergency action plan” means a plan that assists a dam owner or operator, and local emergency management personnel, to perform actions to ensure human safety in the event of a potential or actual dam failure.

“High hazard rating” means that the department expects loss of human life to occur if a dam fails.

“Maintenance action” means measures that are necessary to address a condition that, if left unaddressed, may cause a dam to become unsafe or potentially unsafe.

“Potentially unsafe” means that, based on an inspection or analysis:

It is probable that a dam cannot withstand an extreme flood or earthquake; or

The dam has a high risk of internal erosion.

“Significant hazard rating” means the department does not expect loss of life to occur if a dam fails, but does expect extensive damage to property or public infrastructure.

“Unsafe” means that, based on an inspection or analysis:

It is probable that a dam cannot be depended upon to retain or pass water or wastewater as designed or operated; and

Inability of the dam to retain or pass water or wastewater as designed or operated could result in dam failure.