PPS 15 Planning and Flood Risk (Revised)·Page 44·6.46
Planning permission required for culverting and canalisation
Written consents for watercourse works do not constitute planning permission for culverting or canalisation activities. Undertaking such operations without planning permission is a breach of planning control subject to enforcement action.
written consents do not constitute planning permission to undertake culverting or canalisation activities. Such an operation carried out without planning permission is a breach of planning control which could result in enforcement action to undertake remedial action.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/PPS 15 - Planning and Flood Risk (Revised).pdf