This league table ranks the 77 sites in the National Rivers Water Quality Network (NRWQN) from most (1) to least (77) suitable for contact recreation, e.g. swimming.
The ranking is based on visual clarity and faecal pollution (as indicated by E. coli bacteria). The lower of the two 'suitability' values for each river indicates whether faecal pollution or visual clarity is the greater problem and determines the overall rating. The entries are colour coded as follows:
eminently suitable | suitable | marginally suitable | unsuitable | totally unsuitable |
To get the full picture it's important to read the accompanying technical report:
This contains details of how the index was developed and how it was applied to data from the NRWQN.
Read more in the Water & Atmosphere article 'How clean are our rivers?'
The League Table
Rank | NRWQN Site code | River name | visibility (m) | Suitability based on visibility | E. coli | Suitability based on E. coli | Water quality index | Limiting variable |
---|---|---|---|---|---|---|---|---|
1 | NN2 | Motueka at Gorge | 11.49 | 98.0 | (cfu/100 mL) | 100.0 | 98.0 | Clarity |
2 | RO6 | Waikato at Reids Farm | 7.51 | 93.3 | 1 | 100.0 | 93.3 | Clarity |
3 | HV4 | Ngaruroro at Kuripapango | 6.65 | 91.7 | 2 | 100.0 | 91.7 | Clarity |
4 | DN10 | Monowai below Gates | 6.53 | 91.5 | 1 | 100.0 | 91.5 | Clarity |
5 | AX1 | Clutha at Luggate Br. | 5.70 | 89.2 | 2 | 100.0 | 89.2 | Clarity |
6 | RO1 | Tarawera at Lake outlet | 5.35 | 87.9 | 1 | 100.0 | 87.9 | Clarity |
7 | WN2 | Hutt at Kaitoke | 4.93 | 86.2 | 4 | 96.9 | 86.2 | Clarity |
8 | WN5 | Ruramahanga at SH2 | 4.35 | 83.2 | 13 | 83.3 | 83.2 | Clarity |
9 | TK5 | Hakatakamea above MH Br. | 4.10 | 81.6 | 13 | 83.3 | 81.6 | Clarity |
10 | NN1 | Motueka at Woodstock | 4.37 | 83.3 | 16 | 80.3 | 80.3 | E. coli |
11 | GY3 | Grey at Waipuna | 3.62 | 78.0 | 11 | 85.9 | 78.0 | Clarity |
12 | TK4 | Waitaki at Kurow | 3.44 | 76.4 | 1 | 100.0 | 76.4 | Clarity |
13 | TU2 | Tongariro at Turangi | 3.14 | 73.5 | 16 | 80.3 | 73.5 | Clarity |
14 | NN3 | Wairau at Dip Flat | 2.84 | 70.0 | 2 | 100.0 | 70.0 | Clarity |
15 | HV6 | Mohaka at Glenfalls | 2.83 | 69.8 | 26 | 71.4 | 69.8 | Clarity |
16 | AX4 | Clutha at Millers Flat | 2.73 | 68.6 | 11 | 86.2 | 68.6 | Clarity |
17 | GY4 | Haast at Roaring Billy | 2.42 | 64.2 | 3 | 98.7 | 64.2 | Clarity |
18 | TK3 | Opuha at Skipton Br. | 2.41 | 64.1 | 33 | 66.9 | 64.1 | Clarity |
19 | HM6 | Ohinemuri at Karangahake | 2.59 | 66.8 | 43 | 62.0 | 62.0 | E. coli |
20 | CH1 | Hurunui at Mandamus | 2.18 | 60.3 | 9 | 89.4 | 60.3 | Clarity |
21 | NN4 | Wairau at Tuamarina | 2.12 | 59.3 | 6 | 93.1 | 59.3 | Clarity |
22 | GY2 | Grey at Dobson | 2.12 | 59.2 | 37 | 64.8 | 59.2 | Clarity |
23 | TK6 | Waitaki at SH1 Br. | 2.09 | 58.8 | 32 | 67.8 | 58.8 | Clarity |
24 | DN7 | Oreti at Lumsden | 4.25 | 82.6 | 50 | 58.6 | 58.6 | E. coli |
25 | AX2 | Kawarau at Chards | 2.06 | 58.2 | 3 | 98.7 | 58.2 | Clarity |
26 | TK1 | Opihi at Waipopo | 4.04 | 81.2 | 52 | 57.9 | 57.9 | E. coli |
27 | RO3 | Rangitaiki at Murapara | 2.01 | 57.2 | 20 | 76.2 | 57.2 | Clarity |
28 | CH2 | Hurunui at SH1 Br. | 1.88 | 54.8 | 65 | 53.5 | 53.5 | E. coli |
29 | DN6 | Mataura at Parawa | 2.29 | 62.2 | 66 | 53.0 | 53.0 | E. coli |
30 | RO4 | Whirinaki at Galatea | 1.76 | 52.4 | 42 | 62.3 | 52.4 | Clarity |
31 | HV2 | Tukituki at Red Br. | 1.68 | 50.7 | 34 | 66.5 | 50.7 | Clarity |
32 | GY1 | Buller at Te Kuha | 1.68 | 50.6 | 20 | 76.2 | 50.6 | Clarity |
33 | WN4 | Ruamahanga at Wardells | 1.87 | 54.6 | 75 | 50.3 | 50.3 | E. coli |
34 | WH1 | Waipapa at Forest Ranger | 2.26 | 61.6 | 82 | 48.7 | 48.7 | E. coli |
35 | NN5 | Buller at Longford | 1.57 | 48.3 | 23 | 73.8 | 48.3 | Clarity |
36 | DN9 | Waiau at Tuatapere | 1.87 | 54.6 | 88 | 47.2 | 47.2 | E. coli |
37 | HV1 | Makaroro at Burnt Br. | 1.50 | 46.6 | 12 | 84.4 | 46.6 | Clarity |
38 | TK2 | Opihi at Rockwood | 2.18 | 60.3 | 91 | 46.5 | 46.5 | E. coli |
39 | DN4 | Clutha at Balclutha | 1.46 | 45.5 | 42 | 62.4 | 45.5 | Clarity |
40 | WN3 | Ruamahanga at Waihenga | 1.45 | 45.3 | 96 | 45.4 | 45.3 | Clarity |
41 | WA5 | Rangitikei at Mangaweka | 1.41 | 44.4 | 82 | 48.7 | 44.4 | Clarity |
42 | HV5 | Mohaka at Raupunga | 1.36 | 43.2 | 20 | 76.7 | 43.2 | Clarity |
43 | WA2 | Manganui at SH3 | 3.83 | 79.7 | 108 | 43.0 | 43.0 | E. coli |
44 | DN8 | Oreti at Riverton HW Br. | 1.35 | 42.9 | 61 | 54.8 | 42.9 | Clarity |
45 | TU1 | Whanganui at Te Maire | 1.31 | 41.8 | 91 | 46.6 | 41.8 | Clarity |
46 | HV3 | Ngaruroro at Chesterhope | 1.30 | 41.7 | 29 | 69.8 | 41.7 | Clarity |
47 | WN1 | Hutt at Boulcott | 2.75 | 68.8 | 121 | 40.7 | 40.7 | E. coli |
48 | DN2 | Sutton at SH87 | 2.31 | 62.6 | 129 | 39.5 | 39.5 | E. coli |
49 | RO5 | Rangitaiki at Te Teko | 1.20 | 39.0 | 31 | 68.3 | 39.0 | Clarity |
50 | HM3 | Waikato at Hamilton Traffic Br. | 1.19 | 38.6 | 56 | 56.6 | 38.6 | Clarity |
51 | DN3 | Taieri at Outram | 1.14 | 37.4 | 44 | 61.2 | 37.4 | Clarity |
52 | WA7 | Manawatu at Weber Rd | 1.10 | 36.2 | 155 | 35.9 | 35.9 | E. coli |
53 | GS3 | Motu at Waitangirua | 1.69 | 50.9 | 158 | 35.5 | 35.5 | E. coli |
54 | WA3 | Waingongoro at SH45 | 1.36 | 43.3 | 161 | 35.2 | 35.2 | E. coli |
55 | WH2 | Waitangi at Wakelins | 1.46 | 45.5 | 167 | 34.4 | 34.4 | E. coli |
56 | WA9 | Manawatu at Opiki Br. | 0.99 | 33.0 | 91 | 46.5 | 33.0 | Clarity |
57 | WA8 | Manawatu at Teachers Coll. | 0.97 | 32.4 | 141 | 37.7 | 32.4 | Clarity |
58 | WA4 | Whanganui at Paetawa | 0.96 | 32.2 | 105 | 43.7 | 32.2 | Clarity |
59 | DN1 | Taieri at Tiroiti | 0.96 | 32.0 | 99 | 44.9 | 32.0 | Clarity |
60 | WA6 | Rangitikei at Kakariki | 0.86 | 29.0 | 124 | 40.3 | 29.0 | Clarity |
61 | GS2 | Waikohu at No. 1 Br. | 1.70 | 51.0 | 225 | 28.9 | 28.9 | E. coli |
62 | GS4 | Motu at Houpoto | 0.85 | 28.7 | 21 | 75.8 | 28.7 | Clarity |
63 | RO2 | Tarawera at Awakaponga | 0.81 | 27.2 | 86 | 47.6 | 27.2 | Clarity |
64 | HM4 | Waikato at Rangiriri | 0.79 | 26.8 | 123 | 40.4 | 26.8 | Clarity |
65 | HM1 | Waipa at Otewa | 1.49 | 46.4 | 276 | 25.3 | 25.3 | E. coli |
66 | HM5 | Waihou at Te Aroha | 0.69 | 23.2 | 238 | 27.8 | 23.2 | Clarity |
67 | AK2 | Rangitopuni at Walkers | 0.68 | 22.9 | 236 | 28.0 | 22.9 | Clarity |
68 | AK1 | Hoteo at Gubbs | 0.66 | 22.3 | 126 | 40.0 | 22.3 | Clarity |
69 | WH4 | Wairu at Purua | 0.65 | 22.1 | 99 | 44.9 | 22.1 | Clarity |
70 | WH3 | Mangakahia at Titoki Br. | 0.65 | 22.0 | 249 | 27.1 | 22.0 | Clarity |
71 | AX3 | Shotover at Bowens Peak | 0.63 | 21.1 | 2 | 100.0 | 21.1 | Clarity |
72 | CH3 | Waimakariri at Gorge | 0.60 | 20.2 | 67 | 52.8 | 20.2 | Clarity |
73 | WA1 | Waitara at Bertrand Rd | 0.59 | 19.7 | 344 | 21.6 | 19.7 | Clarity |
74 | HM2 | Waipa at Whatawhata | 0.50 | 16.5 | 273 | 25.5 | 16.5 | Clarity |
75 | DN5 | Mataura at Seaward Down | 0.90 | 30.1 | 488 | 16.2 | 16.2 | E. coli |
76 | CH4 | Waimakariri above old HW Br. | 0.29 | 8.4 | 36 | 65.2 | 8.4 | Clarity |
77 | GS1 | Waipoa at Kanakanaia | 0.11 | 0.7 | 126 | 40.0 | 0.7 | Clarity |