Mean monthly river flows for the year compared against the previous year and the long-term average/range. Hover over charts to see specific values and click on legend entries to show/hide that series.
Kāpiti Coast
Te Awarua-o-Porirua
Te Whanganui-a-Tara
Ruamāhanga
Wairarapa Coast
Note that for all frequency analysis results (high or low flows and rainfall) a return period expressed as 100 years can be assigned a probability of occurring being 1/100, or 1% in any one year. Similarly, a 5-year return period event equates to 1/5 or a 20% chance of occurring in any one year.
Note that for all frequency analysis results (high or low flows and rainfall) a return period expressed as 100 years can be assigned a probability of occurring being 1/100, or 1% in any one year. Similarly, a 5-year return period event equates to 1/5 or a 20% chance of occurring in any one year.
As part of its flood warning and response service, GWRC sets high river level alarms on many of its monitoring sites to provide early warning of rising river levels and possible flooding. Below shows the rivers and sites where flood warning alarms were triggered. Hover over the chart to see which site/s exceeded alarm levels.