Waikato river unsafe for kayaking February 11th, 2020 2002-04-15T13:06:47+12:00 Environment Waikato and Waikato Medical Officer of Health Dr Dell Hood are warning recreational users of the river between Hamilton and Ngaruawahia that the level of bacteria in the water was currently well above the level considered safe and any water contact should be avoided. Risks include bacterial infections, giardia, cryptosporidium and Hepatitis A. Contamination is due to intensive farming and stormwater runoff (Waikato District Health Board statement). Update: 8 May, The pollution has been traced to a Hautapu dairy factory.