Overview of scoring pattern:

Rapid Risk Assessment for Specified Dam (RRASD) application is designed for indexing the specified dams based on risk score estimated from fragility and  potential impacts if the dam fails. Both fragility and potential impact have been assigned  weigths to estimate their corresponding indexes. The RRASD ranks dams from 0 to 250000  reflecting low risk to high risk score for dams respectively. 

• 1

  Risk has been expressed as a simple product of Fragility Index (F.I.) and Potential Impacts (P.I.). (Risk = Fragility index × Potential impacts)

• 2

  Both, F.I. and P.I., shall have score of 500 in the worst case scenario, i.e. a dam which is having worst scores in F.I. & P.I., both, shall have a risk score of 500 × 500 = 2,50,000.

• 3

  The 500 score assigned to F.I. is further divided into three broad categories:

  • Technical Characteristics (TC) [Weightage = 104]
  • Existing Conditions (EC) [Weightage = 328]
  • Safety Plans (SP) [Weightage = 68]
  104 + 328 + 68 = 500
• 4

  TC section pertains to questions related on various design aspects such as inflow flood design, seismic design, filter design, foundation etc. The TC section contains 8 sheets. In each sheet, several questions have been asked on a particular topic. The break-up of total score (104) of TC section is given below:

  • TC-1 Age [Weightage = 3]
  • TC-2 Inflow Design Flood [Weightage = 16]
  • TC-3 Seismic Design [Weightage = 8]
  • TC-4 Landslides, GLOFs, LDOFs, Debris Flow and Sedimentation [Weightage = 7]
  • TC- 5 Length [Weightage = 3]
  • TC-6 Conduits in embankments and overburden abutments/foundations [Weightage = 15]
  • TC-7 Filters [Weightage = 24]
  • TC-8 Foundation [Weightage = 28]; It has highest weightage in TC section.
  3 + 16 + 8 + 7 + 3 + 15 + 24 + 28 = 104
• 5

  EC sheet pertains to questions based on the present condition of different components of dams such as gates, spillway, embankment, masonary and concrete. The EC section contains 8 sheets. In each sheet, several questions have been asked on a particular topic. The break-up of total score (328) of EC section is given below:

  • EC-1 Seismic Resistance [Weightage = 18]
  • EC-2 Flow Discharge Equipment [Weightage = 65]
  • EC-3 Back-up Power [Weightage = 12]
  • EC-4 Access to site [Weightage = 6]
  • EC-5 Concrete Gravity Dam [Weightage = 26]
  • EC-6 Spillway [Weightage = 30]
  • EC-7 Masonary Dam [Weightage = 37]
  • EC-8 Embankment, Abutments and Foundation [Weightage = 70]; It has highest weightage in EC section.
  18 + 65 + 12 + 6 + 26 + 30 + 37 + 70 = 328
• 6

  SP sheet pertains to questions on the safety plans and available documentation i.e. design drawings, safety inspection reports, O & M Manual etc. The EC section contains 8 sheets. In each sheet, several questions have been asked on a particular topic. The break-up of total score (68) of EC section is given below:

  • SP-1 Documentation [Weightage = 2]
  • SP-2 Operations and Maintenance Manual [Weightage = 8]
  • SP-3 Emergency Action Plan [Weightage = 8]
  • SP-4 Organization, Staffing and Competence [Weightage = 3]
  • SP-5 Safety Inspections, Monitoring and Reporting  Procedures [Weightage = 7]
  • SP-6 Dam Safety Reports with Analysis and Interpretation [Weightage = 6]
  • SP-7 Follow-up Actions [Weightage = 16]
  • SP-8 River System Operation [Weightage = 18]
  2 + 8 + 8 + 3 + 7 + 6 + 16 + 18 = 68
• 7

  The 500 score assigned to P.I. (Potential Impacts) is further divided into three categories:

  • Population at Risk [Weightage = 375]
  • Environmental Impacts [Weightage = 35]
  • Socio-economic Impacts [Weightage = 90]
  375 + 35 + 90 = 500