| Reason for Spill |
Coleridge |
Matahina |
Waipori |
Total |
| Plant |
|
0.16 |
0.8 |
0.96 |
| Obstruction |
|
|
|
|
| High Flow |
|
0.01 |
1.33 |
1.34 |
| Regulation |
|
|
|
|
| Legal |
|
|
|
|
| Recreational |
|
|
|
|
| Support |
|
|
|
|
| Commercial |
|
|
|
|
| Transmission |
|
|
|
|
| Other |
|
|
|
|
| Total Energy (GWh) lost due to spill |
0 |
0.16 |
2.13 |
2.3 |
| Hydro Energy (GWh) Produced |
52.25 |
105.28 |
82.17 |
239.7 |
| % Energy lost due to Spill |
0 |
0.15 |
2.53 |
0.95 |
Plant
The hydro-release results from a malfunction in a plant owned by Trustpower or a third party. For example: a generator develops a serious fault and must be shut down, so water already released for generation must be spilled.
Obstruction
The hydro-release results from a physical obstruction to a plant. For example: river debris clog the intake screens that protect generators; cleaning requires the generators to be turned off, so the water that can’t be stored must be spilled.
High flow
The hydro-release results from inflow water levels that exceed what the Scheme can handle and there’s no storage capacity. For example: during times of flooding or very high rainfall.
Regulation
The hydro-release supports regulatory obligations, such as Resource Consents, use permits and bylaws. For example: Matahina’s Resource Consent requires a minimum river flow at all times.
Legal
The hydro-release results from legal or contractual obligations, where Trustpower has no other option.
Recreational
The hydro-release supports recreational, social or cultural use. For example: a white water kayaking competition.
Support
The hydro-release is driven by economic reasons. For example: a weak energy demand makes the release the only economic option.
Commercial
The hydro-release results from the electricity spot price not meeting the minimum threshold for operating economically.
Transmission
The hydro-release is due to transmission or distribution issues.
Other
The hydro-release results from reasons other than those described above.