Del. Code tit. 23 § 1508
The littoral proprietors abutting on the River Delaware, between Christina River and the northerly boundary of Edge Moor, may erect bulkheads, wharves and piers on the line or lines now or hereafter to be fixed, established and adopted as provided in § 1505 of this title, opposite their respective littoral holdings on the river, between the Christina River and the northerly boundary of Edge Moor, and fill in with earth, stones or other material the space or spaces between the bulkhead line or lines of solid filling shown or exhibited on the map or maps, report or reports referred to in § 1505 of this title, and the westerly bank of the river (designating the high watermark thereof), between the Christina River and the northerly boundary of Edge Moor. Nothing contained in this section shall operate to prevent the United States from utilizing all or any portion of the space between the bulkhead and the westerly bank of the river for the deposit of dredged material taken from the River Delaware in the progress of the improvement thereof, not exceeding 12 feet in height above mean low water. The filling in of the space between the lines by any littoral proprietor shall be under and subject to the regulations of the Department of the Army of the United States.
23 Del. C. § 1508