Table 3. Status grade by detailed inspection on concrete erosion control dam (from ΓGuidelines for the Maintenance of the Erosion Control Facility┘).

Grade	Total score	Status of concrete erosion control dam
A(Good, repair if necessary)	< 30	Good condition without any problems such as deformation or damage
B(Repair)	30 ≤, < 70	Condition in which some defects have occurred, but there is no hindrance to the functioning of the facility, and some repairs are required
C(Reinforcement or improvement)	70 ≤	Condition in which urgent reinforcement or improvement is required due to a decrease in the function of the facility and an abnormality in safety management by the occurrence of a serious defect
D(Safety diagnosis)	70 ≤	Condition in which unsafety is expected due to a serious defect, but additional safety diagnosis is required because it is insufficient to suggest countermeasures at the level of detailed inspection
E(Additional construction or re/replacement construction)	70 ≤	Condition in which additional construction or re/replacement construction is required when it is impossible to supplement or improve construction, or it is economically inefficient, even when serious defects are found