In addition to above there are (in Edale)
http://www.upperboothcamping.co.uk/
(very close) http://www.fieldhead-campsite.co.uk/
or if you want to be out of Edale, try
(Hope, 10 mins drive) http://www.lanesidecaravanpark.co.uk/
(Bradwell, 15 mins drive and good chippy and pubs) http://www.edentreecaravanpark.co.uk/