Low flow statistics

Nelson City Council monitor river flow in a number of rivers across our region. At some sites we measure flows continuously whilst at other sites we take spot measurements periodically. From this data we can calculate a variety of statistics to inform a range of applications including resource use and management, drought and flood management, recreational use, infrastructure design and compliance monitoring . The tables below show the mean and median flows and 7-day MALF for rivers in our region.  7-day MALF is the Mean Annual Low Flow. This is calculated by finding the lowest running 7 day average for each year of the record and then averaging all of those low flows over the whole record period. 

Statistics calculated from long term flow records

  Mean (l/s) Median (l/s) 7 day MALF (l/s)
Collins at Drop Structure 542 220 63.6
Maitai at Avon Tce 2416 882 358
Maitai at Forks 1431 534 209
Maitai Sth at Above Old Intake 843 392 161
Orphanage at Ngawhatu 78 25 4.8
Roding at Caretakers 1625 519 98
Roding at Skid Site 1640 591 218
Wakapuaka at Hira 1344 733 306

 

Statistics calculated based on correlations

Statistics for these sites are calculated based on correlations with similar sites as there is no continuous monitoring at these sites. Therefore the flows can only be considered an estimate.

  Mean (l/s) Median (l/s) 7 day MALF (l/s)
Brook at Motor Camp 130 80 40.3
Dencker at Kokorua Rd 176 71.7 21
Graham at SH6 281 142 74.9
Groom at Maitai Confluence 17.2 7.7 1
Jenkins at Pascoe St 54.5 17.1 2.9
Lud at 4.7km 48.1 25.8 10.1
Lud at SH6 121 61 18.6
Maitai at Groom Rd 1810 667 252
Poorman at Barnicoat Walkway 49 29.1 15.1
Poorman at Seaview Rd 55.5 29.5 11.4
Sharland at Maitai Confluence 171 86 26
Teal at 1.6km 398 219 93
Todds at SH6 28.6 14 3.8
Wakapuaka at Duckpond Rd 727 421 207
Wakapuaka at Maori Pa Rd 1676 869 305
Whangamoa at Hippolite Rd 832 446 177
Whangamoa at Kokorua Bridge 2535 1083 377
York at Waimea Rd 13.3 4.4 1
Hillwood at Intake 17.3 8.4 2.1
Oldham Lower (Corder Park) 35 17.3 4.9
Waihi at Glen 14.7 8.9 6
Orchard at Nayland Rd 27 12 4

Disclaimer: This data is current as of November 2016. All calculations are based on the best information available at the time and professional judgement of an expert. NCC cannot guarantee the data or data capturing process is free from error. Caution should be exercised when using this data. More information is available on application.