It’s a critical part of the whole Straitgate Farm application - to maintain drinking water supplies and stream flows, to control flooding and to prevent on-site ponding for birdstrike considerations. It's a part of the application you would hope that Aggregate Industries would be completely open and up-front about.
AI says on-site surface water management "relies on the natural high permeability of the geology to allow infiltration of water into the ground" 3.29. Exeter Airport responded to AI on the issue, and said:
With regards to the surface water management at Straitgate Quarry: Given the makeup of the quarry, and as you have pointed out in your email, any water settling on the surface should drain quickly… no water will manage to build up in suitable quantities to become an attractant to large flocks of Gull. 3.40
And the exposed geology may be permeable - for 3,4,5 years of extraction. But buried in a report, commissioned by AI, Soil Resources and Agricultural Use & Quality of Land at Straitgate Farm, is this:
At 29 ha, [the Grade 3a land] is the most extensive land grade on the site… The main limitation is limited workability in spring and autumn due to seasonal wetness from water ponding over slowly permeable subsoils. 3.6
It is these slowly permeable subsoils that would provide the infiltration once the site's restored - and could leave ponding, in perpetuity. Of course, AI doesn’t highlight that.
It's one thing misleading locals, it's another thing misleading statutory consultees.
