In connection with any contract, relating to construction charges, entered into pursuant to the authority of this subchapter, the Secretary is authorized to require such provisions as he deems proper to secure the adoption of proper accounting, to protect the condition of project works and to provide for the proper use thereof, and to protect project lands against deterioration due to improper use of water. Any such contract shall require advance payment of adequate operation and maintenance charges. The Secretary is further authorized, in his discretion, to require such provisions as he deems proper to penalize delinquencies in payments of construction charges or operation and maintenance charges: , That in any event there shall be penalties imposed on account of delinquencies of not less than one-half of 1 per centum per month of the delinquent charge from and after the date when such charge becomes due and payable: , That any such contract shall require that no water shall be delivered to lands or parties which are in arrears in the advance payment of operation and maintenance or toll charges, or to lands or parties which are in arrears for more than twelve months in the payment of construction charges due from such lands or parties to the United States or to the organization in which the lands or parties are included, or to any lands or parties included in an organization which is in arrears in the advance payment of operation and maintenance or toll charges or in arrears more than twelve months in the payment of construction charges due from such organization to the United States.ProvidedProvided further