Very interesting Pedro - wonder where Mr Dugard lived?
Here is a section of the modern OS Explorer Map. I have highlighted the 100m contour which seems to stretch from the embankment on Witton Lakes and around Brookvale Park. Also highlighted are the 105 and 110 m contours.
The distance from the embankment to Brookvale Park is roughly half a mile, being the distance that the Navvy wagons were swept. The valve was closed in the Lower Witton Pool which was under construction and the greater part of the water escaped into the pool.
Was the house of Mr. Dugard at Faulkner’s Farm on Gipsy Lane? And where were the Aston Schools that were flooded?