Write a short note on highest flood level(HFL)

 Highest flood level (HFL) When it rains water level of river or jore rises and water spreads on both sides.The rise varies from year to year.The highest level in known history to which water has risen is known as highest flood level or HFL of river/jore.The outer border to which the water spreads on either side is called highest flood line.If there is river or jore near the mine,HFL305m(5.10.2006).It gives an idea of the extent to which the water can spread so that Safety of mine entrance can be ensured.HFL is painted on a concrete pillar built on the surface.Every year durring rainy season the surveyor checks whether the water level has risen to a level higher than HFL,and if so,he surveys the HFL line,amends all mine plans accordingly and reveiws the dangers.It is to be noted that HFL line is not a contour line,In different mines on the same rivers,HFL may be different because width and depth of river may not be the same at all places.