DEHRADUN: Court commissioner Alok Mehra, appointed by the Uttarakhand high court to conduct site inspections and submit a report on the adverse impact of illegal mining on rivers in the state, told the court on Friday that huge pits have been formed, causing serious damage to the ecology of several rivers".The HC directed the government to file an affidavit and submit a proper plan to stop illegal mining in the rivers by December 6, after which the court can consider modifying its previous order banning dredging.The government had moved an application on Thursday to allow dredging, saying the state is not only incurring a loss of Rs 500 crore annually, but infrastructure-related development work is getting disrupted.