Simplify the following text for a Grade 10 native English-speaking person.
Original: Most of the other locks on the River Thames also have walkways across their lock gates and weirs , but these either do not completely cross the river , or are restricted to authorised personnel only , and are therefore not listed .
Simplified: Most of the other locks on the River Thames also have walkways across their lock gates and weirs , but these either do not fully cross the river , or are for the use of authorised people only , and are so are not listed .