precise-level datum

Question

سلام - قسمت هایلایت شده را چی ترجمه کنیم ؟ (در مورد ارتقاء ظرفیت کانال پاناما است.)

The project will also raise the maximum operational level of Gatun Lake, a large artificial lake to the south of Colon that allows ships to transit across the Isthmus of Panama, from a current elevation of 26.7 meters precise-level datum, based on main sea level calculations, to 27.1 meters PLD.