"Names and boundaries as given in First Schedule of the Land Drainage Act with subsequent amendments"

The base map is Sheet 2 of the 1:1M in the style of the International Map of the World (Hellyer, Indexes, 104A2). It shows catchment areas as defined under the 1930 Land Drainage Act. It had long been apparent that the multitude of small drainage authorities would be more cost-effective if they would combine their efforts to improve the main rivers into which their systems drained or were pumped, but hitherto there had been no statutory mechanism for this.

The Act enabled River Boards to be set up within England and Wales which could define catchment areas within which they would exercise their powers. The Ordnance Survey marked these catchment areas on the six-inch. This 1:1M provides a useful overview at the date of the map - changes continued to occur as new statutory orders were made.

The bottom half of the map is missing, along with the date, but it is thought to be about 1937.

Scan of map can be viewed at: https://www.charlesclosesociety.org/rare-others