The aquifers and aquicludes of the Christchurch Artesian System are moderately-tohighly incompetent and elastic, judged by the effects of ocean tides, of the changing water levels of Lake Ellesmere, and of earthquakes and passing heavy vehicles upon water levels in wells tapping them. The “outcrop” hypothesis advanced by Speight (1911) to account for the tidal effect is rejected in favour of one of loading.