(e) Unless a shorter time frame is imposed by the department in the interest of public safety based on the assignment of a condition rating of "unsafe" or "unsound" in accordance with section 673.16 of this Part, the schedule for submission of the first engineering assessment report is as follows.

1. (1) Large class C dams. For dams that have been assigned a hazard classification of class C as of the effective date of this Part, the first engineering assessment report shall be submitted within three years of the effective date of this Part if the dam is a large class C dam, which shall mean the dam either has a height greater than or equal to 40 feet or impounds 1,000 acre-feet or more at normal water surface.
2. (2) Small class C dams. For dams that have been assigned a hazard classification of class C as of the effective date of this Part, the first engineering assessment report shall be submitted within five years of the effective date of this Part if the dam is a small class C dam, which shall mean the dam has a height of less than 40 feet and impounds less than 1,000 acre-feet at normal water surface.
3. (3) Class B dams. For dams that have been assigned a hazard classification of class B as of the effective date of this Part, the first engineering assessment shall be submitted within six years of the effective date of this Part.

4. (4) For dams that are assigned a hazard classification of B or C or are reclassified as such after the effective date of this Part, the first engineering assessment report or other submission in lieu thereof, shall be submitted either:

   1. (i) as part of a permit application pursuant to Part 608 of this Title with respect to the dam; or
   2. (ii) where no activities requiring a permit are pursued, within two years of the department's assignment.
5. (5) The deadlines for the submission of the first engineering assessment report may be extended, at the discretion of the department, in response to a written request by a dam owner who is operating a dam in a safe condition and is not otherwise in violation of this Part.

(f) All engineering assessments shall include:

1. (1) a complete safety inspection pursuant to section 673.12 of this Part and a corresponding safety inspection report;
2. (2) an evaluation of the dam, including its function, structural stability, and spillway capacity, that may utilize calculations or computer modeling of the hydrologic, hydraulic, stability and/or structural analysis; conclusions as to whether the dam is in a safe condition; and the basis for the conclusions; and
3. (3) any recommended change in the hazard classification or modification of the emergency action plan due to changes in the dam or inundation area, including, specifically, changes in land use.