Having spent nearly $1 million to design, install, and maintain a culvert linking Gardiner’s Bay and Accabonac Harbor, East Hampton Town has allowed it to fill with sand, essentially rendering a giant investment of public money useless. The Gerard Drive project was long envisioned as a way to improve water quality in the harbor by providing it with a second tidal opening. To remain functional, however, the culvert needed the sand, which otherwise would accumulate and shut it off, regularly removed.