Your search returned 4 results.
by -- Great Britain National Rivers Authority.
by Smith, D.G. (David Glynn);
Williamson, R. B. (Ronald Bruce).
-- New Zealand Water and Soil Directorate.;
New Zealand National Water and Soil Conservation Authority
by Grindell, D. S;
Scarf, F. (Frank).
-- South Canterbury Catchment Board and Regional Water Board
by Hoare, R.A. (Ministry of Works and Development, Water Quality Centre. Hamilton) (ed.).