Due to this reason March end reports of hydro-power companies show very low profits or loss making results . Most of the years, stocks drop and kept at low prices due to this after March reports.
At the same time you get the opportunity to watch level of rainfall in April - May and the start of SW monsoon. Then you can predict future earnings.
If the raining is good and continuous there will be profits in next reports .
If current rains continued during June very good EPS should come.