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.