(1) As authorized by
RCW
43.21A.064, the department has the authority
to conduct routine periodic inspections of all existing dams with high and
significant downstream hazard classifications to reasonably secure safety to
life and property.
Dams with high downstream hazard classifications will be
inspected every five years.
Dams with significant downstream hazard classifications will
be inspected every five years, or ten years if workload or staffing
necessitates a longer cycle between inspections.
Dams classified as low hazard are not included in the
periodic inspection program.
(a) The
department will give at least thirty days notice of the date of the periodic
inspection and advise the owner of any requirements such as gates or valves
that are to be operated during the inspection.
(b) Fees shall be charged for periodic
inspections conducted by the department. The amount of the fee and owner
requirements for the fee payment are described in WAC
173-175-755 through
173-175-775.
Dam classification
(2) The downstream hazard classification of
existing dams shall be determined by the department in accordance with WAC
173-175-130, Table 3.
(3) The classification of each dam shall be
reviewed during each periodic or other inspection and may be changed as the
result of such inspection.
Components of a periodic inspection
(4) Each periodic inspection shall
consist of, but not be limited to, the following:
(a) Review and analysis of available data on
the design, construction, operation, and maintenance of the dam and its
appurtenances;
(b) Visual
inspection of the dam and its appurtenances, the downstream area, and all other
areas affected by the structure;
(c) Evaluation of the safety of the dam and
its appurtenances, which may include assessment of the hydrologic and hydraulic
capabilities, structural stabilities, seismic stabilities, and any other
condition which could constitute a hazard to the integrity of the
structure;
(d) Evaluation of the
downstream hazard classification;
(e) Evaluation of the operation, maintenance,
and inspection procedures employed by the owner and/or operator; and
(f) Review of the emergency action plan for
the dam including review and/or update of dam breach inundation maps.
(5) The department shall prepare a
written safety inspection report that describes the findings from the
inspection and lists remedial actions that must be taken to ensure the
continued safety of the dam.
(6)
The department shall provide the dam owner with a copy of the written report of
the periodic inspection. The dam owner must correct any identified safety
deficiencies in a timely manner.
