Within the Floodplain District no structure or building shall be erected, constructed, substantially improved or otherwise created or moved; no earth or other materials dumped, filled, excavated, or transferred, unless a special permit is granted by the Board of Appeals. Said Board may issue a special permit hereunder, subject to all other applicable provisions of this bylaw only in accordance with the following provisions:
(1) The proposed use shall comply in all respects with the provisions of the underlying District;
(2) Within 10 days of receipt of the application, the Board shall transmit one copy of the development plan to the Conservation Commission, Planning Board, Board of Health, Select Board and Inspector of Buildings. Final action shall not be taken until reports have been received from the above Boards or until 35 days have elapsed;
(3) All encroachments, including fill, new construction, substantial improvements to existing structures, and other development are prohibited unless certification by a registered professional engineer is provided by the applicant demonstrating that such encroachment shall not result in any increase in flood levels during the occurrence of the one-hundred-year flood.