Abstract: A method of monitoring one or more sumps in order to predict an overflow condition comprising: pumping, using at least one pump (14), liquid from the or each sump (16); monitoring the liquid level in the or each sump (16) using a level monitoring means (24) and outputting liquid level data; monitoring at least one operating condition of the or each pump (16) and outputting pump condition data; and processing the liquid level and pump condition data, using processing means, to predict whether the sump will overflow within a predetermined future period.