Water budget
Over water years 1994 to 2024, about 639 GL of precipitation falls on the watershed in an average year. Most of it, 418.20 GL, returns to the air. 200.95 GL reaches Okanagan Lake (F80).
outputs/lake_budget_v2/OBWB_LakeBudgetWY-wmdem_v2_20261011.csv; F80. Download data (CSV)outputs/lake_budget_v2/OBWB_LakeBudgetMonthly-wmdem_v2_20261011.csv. Download data (CSV)The alluvial fan
Below the gauge, the creek crosses its alluvial fan. From 16 June to 31 August the model takes 3.27 GL per year out of the channel there (D32). That water has three destinations (F81, D61):
2.35 to 3.18
GL per year
Recharge to groundwater
D61; Moderate
0.03 to 0.83
GL per year
Benvoulin surface diversion
F81, D61; Moderate
0.08
GL per year (0.06 to 0.09)
Riparian vegetation water use
D61, F99; Moderate
The Benvoulin range runs from zero where no record exists to the 2016 to 2017 monthly means (F81). Records after 2017 would narrow it.
Transfers across the watershed divide
Two transfers cross the divide between Mission Creek and the West Kettle River (F102).
| Transfer | Direction | Size | In the model | Confidence |
|---|---|---|---|---|
| Stirling Creek diversion into McCulloch Reservoir | Import into Mission Creek | 3.642 GL/yr (1994 to 2017) | Yes (D21) | High on the mechanism; Low on the volume |
| McCulloch South spillway overflow to Pear and Idabel lakes and Stirling Creek | Export to the Kettle | Never measured; modelled 0 GL (WY1994 to 2024) | No | High on the mechanism; Low on the volume |
- The import series is a fixed monthly ratio times WSC gauge 08NM241, not a measurement. The few measurements (1977 to 1979, 1984, 2004 to 2006) differ from it by -24% to +48%.
- From 2018 the model uses the 1998 to 2017 day-of-year mean, 3.618 GL per year.
- The overflow is confirmed in engineering sources. No model represents it, and it has never been measured.
outputs/interbasin_transfers/OBWB_StirlingImportAnnual_v1_20261011.csv; F102. Download data (CSV)Numbers on this page and their sources
| Number | Value | Result file | Decision log | Second check |
|---|---|---|---|---|
| Benvoulin surface diversion high (GL/yr) | 0.83 | outputs/lake_budget_v2/OBWB_FanTermSplit_v2_20261011.csv | F81 | D61 text |
| Benvoulin surface diversion low (GL/yr) | 0.03 | outputs/lake_budget_v2/OBWB_FanTermSplit_v2_20261011.csv | F81 | D61 text |
| Mean evapotranspiration incl. reservoir losses (GL/yr) | 418.20 | outputs/lake_budget_v2/OBWB_LakeBudgetWY-wmdem_v2_20261011.csv | F80 | daily mm x area |
| Mean D32 fan channel loss (GL/yr) | 3.27 | outputs/lake_budget_v2/OBWB_LakeBudgetWY-wmdem_v2_20261011.csvoutputs/lake_budget_v2/OBWB_FanTermSplit_v2_20261011.csv | F80 | fan split table D32 column |
| Mean inflow to Okanagan Lake, WY1994-2024 (GL/yr) | 200.95 | outputs/lake_budget_v2/OBWB_LakeBudgetWY-wmdem_v2_20261011.csv | F80 | daily mm x area |
| Mean precipitation (GL/yr) | 639 | outputs/lake_budget_v2/OBWB_LakeBudgetWY-wmdem_v2_20261011.csv | none | daily mm x area |
| Fan recharge high after riparian ET (GL/yr) | 3.18 | outputs/lake_budget_v2/OBWB_FanTermSplit_v2_20261011.csvoutputs/wetland_riparian_et/OBWB_FanRiparianETVolumes_v1_20261011.csv | D61 | F81 printed recharge minus D61 printed riparian low |
| Fan recharge low after riparian ET (GL/yr) | 2.35 | outputs/lake_budget_v2/OBWB_FanTermSplit_v2_20261011.csvoutputs/wetland_riparian_et/OBWB_FanRiparianETVolumes_v1_20261011.csv | D61 | F81 printed recharge minus D61 printed riparian high |
| Riparian ET on the fan reach, central (GL/yr) | 0.08 | outputs/wetland_riparian_et/OBWB_FanRiparianETVolumes_v1_20261011.csv | D61 | none |
| Riparian ET high | 0.09 | outputs/wetland_riparian_et/OBWB_FanRiparianETVolumes_v1_20261011.csv | D61 | none |
| Riparian ET low | 0.06 | outputs/wetland_riparian_et/OBWB_FanRiparianETVolumes_v1_20261011.csv | D61 | none |
| Modelled McCulloch spill WY1994-2024 (GL) | 0 | outputs/interbasin_transfers/OBWB_McCullochSpillModel_v1_20261011.csv | F102 | count of years with days above crest |
| Stirling import fill 2018-2024 (GL/yr) | 3.618 | outputs/interbasin_transfers/OBWB_StirlingImportAnnual_v1_20261011.csv | F102 | fill column |
| Stirling import mean 1994-2017 (GL/yr) | 3.642 | outputs/interbasin_transfers/OBWB_StirlingImportAnnual_v1_20261011.csv | F102 | OHME active-sheet column |