Case study: Willen Lake.2C Milton Keynes Balancing lake

willen lake (north basin), spill-way in background

willen lake (52°03′25″n 0°43′10″w / 52.05694°n 0.71944°w / 52.05694; -0.71944) 1 of largest (400,000 m²) purpose-built stormwater balancing lakes in uk. lake designed take surface run-off milton keynes, largest of number designed so. lake has capacity additional level increase of 1.3 metres, equivalent once in 200 years event. unlike of rest of uk, city has separate storm , foul sewers, sewage pollution not significant problem. additionally, there facilities prevent accidental oil spills , reaching lake. local storm drains, lake s primary purpose intercept river ouzel, tributary of river great ouse. catchment area oxford clay tends saturated easily, field run-off has been problem.

the south basin designed recreational use, dinghy sailing , wind surfing, circumference path , banks described above. linked north (wild-life) basin , can drawn on manage level of latter more finely. north basin has large, undisturbed, central island. extensive shallows support crop of aquatic plants , invertebrates. quickly, became key wildfowl site. in winter, attracts 2,500 wild birds, wide variety of migrating waders in spring , autumn. common tern, tufted duck, ringed , little ringed plover, common redshank , northern lapwing. canada geese have become naturalised , permanent residents. both basins have deep ponds maintain fish population during droughts. lake managed public open space, receiving million visits each year.