Authority: IC 14-27-7.5-8

Affected: IC 14-27-7.5

Sec. 1. (a) The division shall assign whether a dam is classified as:

1. (1) high hazard;
2. (2) significant hazard; or
3. (3) low hazard;

based on best information available.

(b) In making the determination of assignment under subsection (a), the division shall apply existing U.S. Army Corps of Engineers Phase 1 reports and other appropriate documentation.

(c) The division may also consider observations of the dam and the vicinity of the dam, including the risk posed to human life and property if the dam fails.

1. (1) If an uncontrolled release of the structure's contents due to a failure of the structure may result in any of the following, the dam shall be considered high hazard:

   1. (A) The loss of human life.

   2. (B) Serious damage to:

      1. (i) homes;
      2. (ii) industrial and commercial buildings; or
      3. (iii) public utilities.

   3. (C) Interruption of service for more than one (1) day on any of the following:

      1. (i) A county road, state two-lane highway, or U.S. highway serving as the only access to a community.
      2. (ii) A multilane divided state or U.S. highway, including an interstate highway.
   4. (D) Interruption of service for more than one (1) day on an operating railroad.
   5. (E) Interruption of service to an interstate or intrastate utility, power or communication line serving a town, community, or significant military and commercial facility, in which disruption of power and communication would adversely affect the economy, safety, and general well- being of the area for more than one (1) day.

2. (2) If an uncontrolled release of the structure's contents due to a failure of the structure may result in any of the following, the dam shall be considered significant hazard:

   1. (A) Damage to isolated homes.

   2. (B) Interruption of service for not more than one (1) day on any of the following:

      1. (i) A county road, state two-lane highway, or U.S. highway serving as the only access to a community.
      2. (ii) A multilane divided state or U.S. highway, including an interstate highway.
   3. (C) Interruption of service for not more than one (1) day on an operating railroad.

   4. (D) Damage to important utilities where service would be interrupted for not more than one (1) day, but either of the following may occur:

      1. (i) Buried lines can be exposed by erosion.
      2. (ii) Towers, poles, and aboveground lines can be damaged by undermining or debris loading.
3. (3) If an uncontrolled release of the structure's contents due to a failure of the structure does not result in any of the items given in subdivision (1) or (2) and damage is limited to either farm buildings, agricultural land, or local roads, the dam shall be classified as low hazard.

(d) The division may modify an assignment of hazard classification, made previously under this article, if changes in the downstream development affect the potential for loss of human life and property.

(Natural Resources Commission; 312 IAC 10.5-3- 1; filed Jan 26, 2007, 10:45 a.m.: 20070221-IR-312060092FRA; readopted filed Sep 19, 2013, 10:13 a.m.: 20131016-IR- 312130162RFA; readopted filed Jul 18, 2019, 8:57 a.m.: 20190814-IR-312190291RFA; readopted filed Mar 25, 2025, 9:50 a.m.: 20250423-IR-312240574RFA)