NOTE: The 10 year flood and low flow statistics provided are just indicators. For some uses a more rigorous analysis is required, especially design or water planning purposes.
Flows are in cubic metres/second.

				7 day low flow		Floods
River	Site	Catchment Area (km²)	Mean Flow	Mean annual	10 year return period	Mean annual	10 year return period
Clarence	Jollies	440	14.9	3.3	2.2	195.7	317
Waiau	Marble Pt	1980	98	32.2	21.9	1059	1413
Hope	Glynn Wye	696	45.9	14.1	10.4	540	710
Hurunui	Mandamus	1070	52.9	16.6	11.4	531	831
Waipara	White Gorge	370	3.0	0.11	0.034	129	249
Ashley	Lees Valley	121.1	3.9	0.79	0.50	75	119
Ashley	Gorge	472	12.3	2.2	1.2	298	539
Okuku	Fox Ck	222	4.4	0.54	0.30	151	273
Waimakariri	Old Highway Bridge	3210	122	40.2	27.4	1495	2344
Cust	Threlkelds Rd	191	1.4	0.30	0.13	55	83
Avon	Gloucester St	36.5	1.9	1.4	1.3	17.4	25.7
Selwyn	Whitecliffs	164	3.3	0.80	0.58	79	152
Selwyn	Coes Ford	678	3.3	0.63	0.31	156	338
Kaituna	Kaituna Valley Rd	39.5	0.6	0.031	0.008	33	71
Rakaia	Fighting Hill	2626	221	92	76	2514	3701