PUB00008

• Year: 2005
• Title: State Engineer's 20th Annual Report on Dam Safety
• CWCB Section: Finance
• Author: Division of Water Resources
• Description: State Engineer's 20th Annual Report on Dam Safety
• Publications - Doc Type: Other

GUIDELINES FOR DETERMINING CONDITIONS

GOOD

CONDITIONS OBSERVEO - APPLIES TO UPSTREAM SLOPE, CREST, DOWNSTREAM SLOPE, OUTLET, SPILLWAY
ACCEPTABLE POOR

In general. this part of the structure has a
near new appearance, and conditions ob-
served in this area do not appear to threaten
the safety of the dam.

Although general cross-section is maintained,
Buriaces may be irregular, eroded. rutted,
spall ed, or otherwise not in new condition.
Conditions in this area do not currently
appear to threaten the safety of the dam.

Conditions observed in this area appear to
threaten the safety of the dam.

GOOD

POOR

No evidence of uncontrolled seepage, No
unexplained increase In flows from designed
drains. All seepage is clear. Seepage con.
ditions do not appear to threaten the safety of
the dam.

CONDITIONS OBSERVED. APPLIES TO SEEPAGE
ACCEPTABLE

Some seepage exists at areas other than the
drain outfalls. or other designed drains. No
unexplained increase in seepage. All seepage
is clear. Seepage conditions observed do not
currently appear to threaten the safety of the
dam.

Seepage conditions observed appear to
threaten the safety of the dam. Examples:
1) Designed drain or seepage flows have
Increased without Increase in reservoir level.
2) Drain or seepage flows contain sediment,
i.e., muddy water or particles in Jar samples.
3) Widespread seepage. concentrated seep-
age or pending appears to threaten the safety
of the dam.

GOOD

Instrumentation and monitoring described
under acceptable ara being exceeded. as
described under comments in the report,

CONDITIONS OBSERVED. APPLIES TO MONITORING

ACCEPTABLE

Instrumentation Is provided In accordance
with the rules. Special instrumentation and
monitoring deemed necessary is provided. The
owner monitors the dam and records data in
accordance with the rules, and submits the
data annually or more frequently if required;

POOR

Required instrumentation and monitoring are
not provided. or required periodic readings Bre
not being made, or unexplained changes in
readings are not reacted to by the owner.

GOOD

CONOITIONS OBSERVED. APPLIES TO MAINTENANCE ANO REPAIR
ACCEPTABLE POOR

Owner has a plan for annual maintenance.
Dam consistently receives effective on-going
maintenance and repair.

Dam receives maintenance in accordance with
a plan, but some maintenance items need to
be addressed. No major repairs are required.

No annual maintenance plan in effect. Dam
does not appear to receive adequate
maintenance. One or more items needing
maintenance or repair have begun to threaten
the safety of the dam. Lack of maintenance
prevents thorough inspection.

SATISFACTORY

The safely inspection Indicates no conditions
that appear to threaten the safety of the dam,
and the dam is expected to perform satisfac.
torily under all design loading conditions.

FULL STORAGE

Dam may be used to full capacity with no con-
ditions attached.

OVERALL CONDITIONS
CONDITIONALLY SATISFACTORY

The safety inspection indicates symptoms of
structural distress (excessive seepage,
evidence of major displacements, etc.) which,
if conditions worsen, could lead to the failure
of the dam. Essential monitoring, inspection
and maintenance must be performed as a
requirement for continued full storage in the
reservoir or storage at a reduced level. There
are no requirements if maintained at the
restricted level.
SAFE STORAGE LEVEL
CONDITIONAL FULL STORAGE

Dam may be used to full storage if certain
monitoring, maintenance, or operational con-
ditions are met.

UNSATISFACTORY

The safety inspection indicates definite signs
of hydrologic inadequacy or structural distress
(excessive seepage, cracks, slides. sinkholes,
severe deterioration, etc.), which could lead to
the failure of the dam if operated at full
storage,

RESTRICTION

Dam may not be used to full capacIty. but
must be operated at some reduced level In
the interest of pulic safety.

Class 1 - Loss of human life is expected in
the event of failure of the dam,

CLASSIFICATION OF DAMS

Class 2 - Significant damage is expected in
the event of failure of the dam, but no loss of
human life is expected.

Class 4 - No loss of human life is expected
and damage will occur only to the dam
owner's property.

Class 3 - A smalt amount of damage is
expected. Loss of human life and significant
damage are not expected.