Ditches were the essential part of road and field drainage before modern pipe drainage was introduced.
There are three that I remember as a child.
One on the south side of Chapel Lane, running from the London Road to the first corner.
Another on the east side of Common Hall Lane running the full length. During cold winters the water in the ditch would freeze and, on our way to Miss Howeship’s school in Arcadian Gardens, we enjoyed skating along the ditch.
The next one was to the west of Castle Lane from the junction with Castle Road West down to the Salvation Army farm entrance by the old post box in the wall, then piped under the road to the east and another ditch down the hill to the fields. Earlier there may have been a ditch the full length of Castle Lane as the part I remember was fed from a buried earthenware pipe coming down from the North of the lane.