The port of Cherbourg was critical to sustaining the allied invasion force and it was always intended to make use of it, especially as it would allow ships sailing directly from the US to offload without intermediate steps in England.
The Allies assumed German forces would both put up stiff resistance and whilst doing so, create as much damage as possible. Both assumptions were proven to be correct.
The Germans surrendered the port on D+20, the 26th of June 1944, a week after the great storm.
Leading the restoration of the port was the US Army 1056th Engineer Group. When they conducted their first survey, the damage found was considerable.
The German engineers had done about as complete a port denial operation as could have been.
A US Officer described it as;
A masterful job, beyond a doubt the most complete, intensive, and best planned demolition in history
In fact, Hitler awarded a Knights Cross to Rear Admiral Walter Hennecke, the Officer in charge of destroying the port.
The Transatlantic Terminal was completely destroyed, the whole area extensively mined, ships scuttled at dock entrances and quaysides and most of the facilities destroyed with copious amounts of HE.
A plan was formulated
Scuttled ships would be removed first, quaysides and other facilities repaired, road and rail links restored and munitions cleared.
The Rhino ferries and LSTs continued their sterling work until the quaysides were repaired.