Nothing in this Act contained shall authorize any Person to take, otherwise than by Agreement, any Land of any Waterworks Company or Waterworks Commissioners, or to alter or interfere with any Works or Property of any such Company or Commissioners, without their previous Consent in Writing, or to authorize any Person to foul or otherwise injuriously interfere with or affect any Stream or Supply of Water which any Waterworks Company or Waterworks Commissioners are authorized to use for the Purposes of their Undertaking.