Losing/Gaining Stream Classification System

Missouri Department of Natural Resources
Division of Geology and Land Survey
Box 250, Rolla, Missouri 65401
Telephone: 314-368-2160

  1. Valley Development:

    1. Cross Section:

      V-shaped (0)
      U-shaped (1)      		 Corresponding magnitude of risk

    2. Longitudinal Section:

      Consistent gradient (0)
      Erratic or variable gradient (1)       		Corresponding magnitude of risk
    3. Channel
      One flow path well defined (0)
      Braided, flat-bottomed, rectangular (1)
      None or sinkholes (4)       		Corresponding magnitude of risk

    4. Vegetation in channel
      Limited or willows (0)
      Dense brush, trees, or weeds (1)       		Corresponding magnitude of risk

    5. Sorting/stratification of alluvium
      Well-sorted persistent stratification (0)
      Poorly developed or none (1)
      		Corresponding magnitude of risk

  2. Bedrock:
    Low permeability (0)
    Low permeability below thin weathered zone (1)
    Persistent open fractures and/or moderate to high permeability (2)
    Karst (4)     		Corresponding magnitude of risk

  3. Flow Characteristics:
    Continuous flow, constant, or increasing (0)
    No flow, intermittent flow, or pools (1)
    Continuous flow but is obviously increasing (2)
    Obvious flow loss (4)
    No flow when adjoining streams have flow (4)     		Corresponding magnitude of risk

  4. Depths to Potentiometric Surface:
    Less than 20 feet (0)
    Greater than or equal to 20 feet (4)    		 Corresponding magnitude of risk
  5. Structural Deforemation (Faults or Folds):
    Unknown or none within one mile (0)
    Known to occur between ½ mile and one mile (1)
    Known to occur less than ½ mile (2)    		 Corresponding magnitude of risk

  6. Water Tracing Results:
    Water remains in channel (0)
    Water loss resurges in alluvial spring(s) or seep(s) downstream in some valley (3)
    Water loss resurges in bedrock spring(s) downstream in some valley or in another watershed (6)     		Corresponding magnitude of risk

  7. Stream Gaging (flow should be at least 0.2 CFS):
    Gaining during low flow conditions (0)
    Flow decreases less than 30% (0)
    Flow decreases more than 30% (6)    		 Corresponding magnitude of risk


Net Survey Score:
Classification: