RIMU hydrology situation report. 2 February 2021
Author:Auckland Council Research and Evaluation Unit, RIMU
Source:Auckland Council Research and Evaluation Unit, RIMU
Total January rainfall was either at or below the long-term normal range. Most of the rain occurred early in the month and during an event on 20 January. The relatively long periods with no rain have effects that are seen in the other hydrological monitoring sites. Soil moisture fell at all sites and only two sites remain in the normal range, with eight sites recording low or very low soil moisture. River flows fell across the region with 29 of 39 sites now below the mean annual low flow (MALF). Nineteen stream sites are below the AUP default minimum flow of 85% MALF. Groundwater levels vary according to geology and water use pressures. Low groundwater levels were generally observed in shallow volcanic and deep Waitematā sandstone aquifers.