Porirua Stream at Town Centre
Daily maximum flow and suspended sediment concentration (SSC) for the 2018/19 monitoring season. SSC is predicted using a turbidity vs discrete SSC model that is updated annually, see last year’s report for more information. The flow event lines represent the flow level at which we would expect n years before another event that size.
Toggle between tabs to see sediment yields/loads of key events and annual totals.
Event Loads
| Event | Duration | Sediment load (t) | Sediment yield (t/ha) | Max flow (m3/s) | Flow return period (years) |
|---|---|---|---|---|---|
| 08-07-2018 - 09-07-2018 | 1 day, 11 hrs & 45 mins | 1184 | 0.30 | 39.6 | 2 |
| 21-07-2018 - 22-07-2018 | 0 days, 6 hrs & 55 mins | 73 | 0.02 | 19.0 | 1 |
| 12-10-2018 - 12-10-2018 | 0 days, 10 hrs & 20 mins | 149 | 0.04 | 16.2 | 1 |
| 19-12-2018 - 20-12-2018 | 1 day, 14 hrs & 55 mins | 257 | 0.07 | 24.5 | 1 |
| 08-03-2019 - 08-03-2019 | 0 days, 10 hrs & 30 mins | 127 | 0.03 | 15.3 | 1 |
| 06-04-2019 - 07-04-2019 | 1 day, 18 hrs & 40 mins | 132 | 0.03 | 15.9 | 1 |
| 11-04-2019 - 12-04-2019 | 1 day, 13 hrs & 40 mins | 471 | 0.12 | 31.7 | 1 |
Annual Loads
| Year | Time | Sediment load (t) | Sediment yield (t/ha/yr) |
|---|---|---|---|
| 2012 | 124 days 12 hrs | 327 | 0.08 |
| 2013 | 365 days | 2,554 | 0.65 |
| 2014 | 365 days | 1,303 | 0.33 |
| 2015 | 365 days | 7,699 | 1.96 |
| 2016 | 366 days | 7,383 | 1.88 |
| 2017 | 365 days | 4,069 | 1.03 |
| 2018 | 365 days | 3,342 | 0.85 |
| 2019 | 180 days | 1,063 | 0.27 |
| Total | 2,495 days 12 hrs | 27,739 | 7.05 |
