The Hororata River has its source in High Peak forest in the mid Canterbury foothills and runs into the Selwyn River on the Canterbury plains. It is a small river with a bed that is predominantly made up of greywacke shingle. However, amongst the shingle one can find agates and very occasionally petrified wood. As the Hororata river is only a 30-40 minute drive from Christchurch it is a popular collecting site. The best time to walk the riverbed is during a fresh straight after a storm that has blown in from the south. South-easterly storms in particular can drop large amounts of rain into the Hororata rivers head waters. One has to be quick though as if you wait for too long for the river to drop all you will find are the footprints of other collectors in the shingle.
Agates collected from the Hororata River tend to be of small to moderate size and show fortification or banding in blues, greys and white. It is not unusual to collect iron stained nodules from the river, however, this colouration is usually confined to the surface of the nodule. Cutting such a stone can be very disappointing and many are left as whole, unpolished display pieces.
Currently the Hororata is overgrown and has a lot of gorse and broom it its bed as it hasnít had a large flood through it for many years. Low water flows during summer also lead to the build up of algal mats that can make collecting difficult. Access to the river can be easily gained from the numerous fords along its course and a walk on the river after rain is always worthwhile even if you donít find anything.
written by Scott Hardwick, Christchurch