It has 4 main tributaries in addition to the Upper Waipara River: Weka Creek, Boby Stream, Home Creek and Omihi Stream. The Waipara River Catchment encompasses an area of approximately 726 km². It is located towards the northern end of the Canterbury Plains, extending some 40 km from the Double Tops Range in the west to the Waipara Lagoon in the east. The Waipara Lagoon is intermittently open to Pegasus Bay in times of larger flows, typically in winter and spring.

The Waipara River Catchment can be separated into two distinct parts. The Upper Waipara is foothill-fed, which means that water flow and yields are generally low in the late summer due to reduced rainfall. The Lower Waipara has higher and more consistent flow due to the inputs from the low-land, spring-fed waterways, Omihi Stream and Home Creek. The natural flow regime of the Waipara River is one of high flows and floods which mostly occur during winter months (but can occur at any time during the year) and generally long periods of low, stable flows during summer and autumn.

The known groundwater resources in the Waipara River Catchment are small, generally low-yielding aquifers in the clay-bound gravels of the Waipara alluvial basin. These aquifers are recharged principally by rainfall infiltration and some recharge from river and stream beds, especially in Weka Creek and Omihi Stream.

Water in the Waipara River Catchment provides essential drinking and stockwater supplies to township and community schemes and individual properties.  It is also used for irrigation of some land within the Waipara River Catchment.  Current takes from the Waipara River and its tributaries are mostly for ‘run of river’ irrigation, but a number of takes are for winter storage (for irrigation) and some for frost-fighting. The most critical time for an irrigation abstraction is the October to April period.  The groundwater in the Waipara River Catchment serves a wide geographic area, but is limited both in terms of the overall quantity available and its somewhat unpredictable spatial distribution. 

The Waipara River has been modified by humans throughout the catchment. The habitat is variable, mainly consisting of exotic vegetation including radiata pine, willows, pasture and general shrubland. The Waipara region has experienced considerable growth in viticulture and horticulture since the 1980s, due to its favourable combination of warm sunny micro climate, isolation from the Canterbury easterly, favourable limestone geology, and alluvial soils. The area is now internationally recognised as a significant producer of wines and horticultural crops such as olives, and this has made it a significant contributor to the local economy and employment.

Within the Waipara River Catchment, the Waipara River is a statutory acknowledgement area under the Ngāi Tahu Claims Settlement Act 1998.  The statutory acknowledgement recognises the particular relationship Ngāi Tahu has with the Waipara River and lagoon.