Heavy rainfall is one of the most frequent and widespread hazards to affect New Zealand. It is defined a rainfall greater than 100mm in 24 hours. 

NIWA scientists are working on improving hazard mitigation and increasing society's resilience to hazards such as heavy rainfall. They are developing and applying improved weather prediction models to accurately forecast severe events in New Zealand. 

"Extreme Weather - Heavy Rainfall." Extreme Weather. N.p., n.d. Web. 14 Apr. 2016

"Storm Brings 100-year Flood to Christchurch, New Zealand - ImaGeo." ImaGeo. N.p., 05 Mar. 2014. Web. 14 Apr. 2016