Reduced runoff to sewers provides additional capacity without expensive engineering work whilst more natural systems improve water quality and the environment.
Trwy leihau llif y dŵr ffo i garthffosydd cynyddir capasiti’r carthffosydd hynny heb waith peirianyddol drud tra bo systemau mwy naturiol yn gwella ansawdd y dŵr a’r amgylchedd.