§ (2) Where, in the opinion of the Board, any agricultural land is injured or likely to be injured by flooding or inadequate drainage which might be remedied wholly or partially by the exercise of drainage powers which are conferred by any general or local Act or an Order having the force of an Act of Parliament, or by any award made under any Act, or by any commission of sewers, and which are not being exercised or, in the opinion of the Board, are being insufficiently exercised, the Board may exercise any such power and also any power conferred by any such Act, Order, award, or commission for defraying the expenses so incurred or for any purpose incidental to the exercise of any such power: Provided that this Sub-section shall not apply to powers conferred upon any railway or canal company for the purposes of their undertaking.