The restrictions, which affect the stretch between locks 75, Big Lock, and 72, Middlewich Top Lock, were announced on Wednesday, July 22, by the Canal and River Trust.
The new rules, which come into force immediately, are intended to save water, which is lost from the canal upstream of locks when they are used.
Big Lock, designed to take wide beam boats, can use up to a staggering 270,000 litres of water during every cycle.
The low water warning comes after the Met Office reported this July has seen just three per cent of its expected rainfall.
While passage between the locks is still possible, boaters can only use locks 75 and 72 between the hours of 10am and 3.15pm, Monday to Friday.
Outside these times, the lock gates will be secured, and passage will not be possible.
Passage remains unrestricted on Saturdays and Sundays.
A further update will be provided on or before Tuesday, August 4.
A CRT spokesman said: “To help manage the water levels, a restriction will be in place at Lock 72 and Lock 75 on the Trent & Mersey Canal.
“Both locks will be open Monday to Friday from 10am, with the last passage at 3.15pm.
“Passage through both locks will remain unrestricted on Saturdays and Sundays.
“During the week, we kindly ask all boaters to ensure they have cleared both locks by 3.15pm, as the locks will be secured outside these operating hours.”