The fact that the fields around Harts Farm are on a flood plain is not news to most people who live nearby. A stream cuts across the site from its source near Elstree Road as it travels downhill towards Sandy Lane.
The Environment Agency have identified land either side of the stream as being Zone 2 (light blue) and Zone 3 (dark blue) flood areas: effectively medium and high risk. This is illustrated in map 1, issued by the Agency for development purposes. Any site containing a Zone 2 and 3 flooding requires a flood assessment, and the rest of the site – which is in Zone 1 – will also need an assessment by virtue of its size. Some houses in Woodfield Rise are in Zones 2 and 3.
We have drone footage of the site taken on a clear day and the extent of the water from the stream and associated surface water is evident. Harts Farm owners have also dug a number of drainage channels in order to alleviate the problem.
The dumping of spoil from the building of the M1 may well have exacerbated the situation and it is also known that historically there were a large number of ponds on the site.
Map 2 identifies current potential flooding from surface water with great swathes of the proposed site and adjacent roads already at low, medium and high risk. Little Bushey Lane is already flooded regularly by the fields and homeowners in The Squirrels and Wayside Avenue report similar problems.
Following reports of flooding in the new development in Rossway Drive, Little Bushey Community undertook a survey to identify the extent of the problem. 31% of homes revealed that they had been affected by flooding since the completion of the building works, indicating the likelihood of further development increasing flooding problems for more properties in the locality.
The revised National Planning Policy Framework, states that to meet the challenge of climate change, flooding and coastal change, plans should have regard to the cumulative impacts of flood risk, rather than just looking at the flood risk impact of individual development sites.