Section 5. Each person making an existing withdrawal in excess of the threshold volume shall file a registration statement in accordance with the regulations adopted by the department, on or before January first, nineteen hundred and eighty-eight; provided, however, that, if the department lowers the threshold volume pursuant to section four, it shall, by regulation, provide a procedure and deadline for persons making existing withdrawals, in excess of the new threshold volume, from water sources to which the new threshold volume is applicable, to file registration statements. Each registrant shall file an annual statement of withdrawal in accordance with regulations adopted by the department. No person shall continue an existing withdrawal in excess of the threshold volume after the applicable deadline for filing registration statements unless such person has complied with the requirements of this section and the regulations adopted hereunder. The department may assist any person making withdrawals in the collection of data and the filing of said registration statement.

Each person making an existing withdrawal below the threshold volume, but in excess of 10,000 gallons per day, may, on or before July first, nineteen hundred and ninety-one, file a registration statement in accordance with regulations adopted by the department. All such voluntary registrations shall have the same standing as above threshold registrations and shall be subject to the same reporting and renewal requirements, and verifications standards, required by the department for above threshold registration statements.

The department shall, by regulation, specify a schedule of expiration dates applicable to each water source from which there are existing withdrawals for which registration statements can be filed. All initial registration statements filed for existing withdrawals from the water source shall authorize such withdrawals until the next applicable expiration date thus specified; provided, however, that no registration statement shall authorize the continuation of existing withdrawals for a term greater than ten years.

The department shall, by regulation, establish a procedure for recognizing, as an existing withdrawal, a volume of water in excess of the average volume of water withdrawn from a particular water source during the period from January first, nineteen hundred and eighty-one to January first, nineteen hundred and eighty-six if such volume of water is within the normal variation of withdrawals made by the registrant; provided that the department shall not use such procedures to recognize, as existing withdrawals, such volumes of water which together exceed the safe yield of the water source from which the withdrawals are being made. Nothing in this section shall be deemed to prohibit any person making an existing withdrawal from obtaining a permit pursuant to section eleven.

Upon the expiration of any initial or renewal registration statement under this section, the registrant shall be entitled, upon the filing of a renewal registration statement, to continue existing withdrawals specified in the registration statement for a period of ten years.