| Well number | M36/7504 | File number | CO6C/20990 |
|---|---|---|---|
| Last known owner | Selwyn District Council | Well status | Sealed / Grouted up |
| Street/road | CNR BIRCHES SPRINGS AND TRENTS ROADS | NZTM grid reference | BX23:60342-74112 |
| Locality | Prebbleton | NZTM X and Y | 1560342 - 5174112 |
| Location description | Southern boundary of reserve on corner of Springs and Birches roads | Location accuracy | 2 - 15m |
| CWMS zone | Selwyn - Waihora | Use | Public Water Supply, |
| Groundwater allocation zone | Selwyn-Waimakariri | Water level monitoring | -- |
| Depth | 128.50m | Water level count | 0 |
| Diameter | 250mm | Initial water level | 2.84m below MP |
| Measuring point description | Top of Bung | Highest water level | |
| Measuring point elevation | 21.95m above MSL (Lyttelton 1937) | Lowest water level | |
| Elevation accuracy | < 0.5 m | First reading | |
| Ground level | 0.30m below MP | Last reading | |
| Strata layers | 44 | Calc min 80% | 12.55m below MP (Estimated) |
| Aquifer name | Wainoni Gravel | Aquifer tests | 1 |
| Aquifer type | Yield drawdown tests | 5 | |
| Drill date | 05 May 2004 | Max tested yield | 48 l/s |
| Driller | McMillan Drilling Ltd | Drawdown at max tested yield | 27 m |
| Drilling method | Rotary/Percussion | Specific capacity | 2.36 l/s/m |
| Casing material | STEEL | Last updated | 05 Jun 2025 |
| Pump type | Last field check | 24 Nov 2015 | |
| Water use data | No |
Screens
| Screen no. | Screen type | Top (m) | Bottom (m) | Slot size (mm) | Slot length (mm) | Diameter (mm) | Leader length (mm) |
|---|---|---|---|---|---|---|---|
| 1 | Stainless steel | 124.5 | 127.5 | ||||
| 2 | Open hole | 127.5 | 128.5 |
Step tests
| Step test date | Step | Yield | Yield GPM | DrawDown | Step duration |
|---|---|---|---|---|---|
| 05 May 2004 | 1 | 23.488081 | 310 | 9.96 | 2 |
| 05 May 2004 | 2 | 32.2014 | 425 | 15.71 | 2 |
| 05 May 2004 | 3 | 40.15704 | 530 | 21.34 | 2 |
| 05 May 2004 | 4 | 48.1126823 | 635 | 27.4 | 2 |
| 05 May 2004 | 5 | 40.9147224 | 540 | 22.5 | 50 |
Comments
| Comment date | Comment |
|---|---|
| 29 Jun 2004 | Sump from127.5 to 128.5 (in screens) Casing is sealed with to -11.6m with cement/bentonite grout. |
| 18 Sep 2009 | Gridref changed from: M36:7033-3558, a result of well visit (by Planning Section) to update table WQL20, of NRRP chapter 4). Old QAR was 4, shifted 150m. Photo added |
| 28 Jul 2016 | NZTM Easting/Northing updated from:1560336-5174113 shifted 5m. From CDWS field QA summer 2015/2016. Other CDWS and well details updated where required. |
| 29 Jul 2016 | Surrounding landuse from CDWS field QA: Residential, roading and lifestyle blocks. Meadow mushrooms approx 100m north |
| 21 Nov 2016 | CDWS Protection zone updated Nov 2016 based on location coordinate update for well. |
| 10 Jan 2023 | Reference Level updated using LiDAR imagery in Dec 2022. The existing RL was 21.33 and the QAR RL was 4. The method of calculating the original RL was: Interpolated DTM. If GL from MP is updated in future please assess if RL also needs to be updated. |
| 10 May 2023 | Dec 2022 Reference Level update using LiDAR was in NZVD 2016, rather than Lyttelton 1937. Rectified in May 2023 by using the previously determined LiDAR elevation value and LINZ conversion tool to calculate Lyttelton 1937 elevation and update Reference Level field. Reference Level updated from 21.622m to 21.952m. |
| 05 Jun 2025 | Well decommissioned by McMillan Drilling 16/5/25. Status updated from Active to Sealed. See C25C/125287 for details |