How drought has shaped the Okanagan

The 1929-1931 drought is the historical benchmark, the worst-case period every Okanagan water-management review still measures against, and the reason the lake’s emergency storage exists.

Local government & infrastructure

• The prolonged 1929-1931 drought was the event that led water managers to recognize the value of Okanagan Lake as a storage reservoir to support irrigation (previously, lake control had targeted only navigation and flood reduction). [High] (source)
• The dam in place during the drought was the third control dam (a rock-filled timber structure built winter 1928-1929, sill 96.0 ft / 340.37 m); it succeeded the experimental first dam of winter 1914-1915 and the second dam of 1920. The pre-1956 dam/bar could not draw the lake below 1119.0 ft, which is why the drought forced river flows to zero rather than deeper lake drawdown. [High] (source)
• The 1935 federal inquiry (post-drought) recommended enabling an additional 1 foot of emergency drawdown (to 97.0 ft / 340.67 m) ‘during periods of severe drought,’ and the South Okanagan Lands Project manager argued for a wider operating range to support irrigation during low-runoff years - policy responses attributable to the 1929-31 experience. [Moderate] (source)
• MODELLED RECURRENCE (not documented 1929-31 cost): the 1974 study estimated that low water levels from a recurrence could total ~$200,000 in direct economic costs if the lake were drawn to 1116.0 ft, including ~$112,000 to let the Kelowna bridge float and ~$100,000 to lower irrigation and domestic water intakes. These are hypothetical recurrence costs under modern operations, since lake levels below 1119.0 ft were never actually experienced. [Moderate] (source)

Quality of life

• MODELLED RECURRENCE (not documented 1929-31 experience): the 1974 study judged that a recurrence of the 1929-31 drought ‘would have significant impacts on recreation and general aesthetics,’ with prolonged low lake levels through summer potentially reducing beach-recreation quality and significantly affecting the tourist industry (lake levels below 1120 ft through summer flagged as significant). Because the pre-1956 dam prevented such low levels, these summer-drawdown tourism impacts did NOT actually occur in 1929-31. [Moderate] (source)
• Wildfire, drinking-water quality, and public-health impacts specific to 1929-31 are ABSENT from the retrieved record. Chapter 4 discusses forest fire only as a long-run average water-yield effect (~5,377 acres/yr basin average), not a 1929-31 event. [High] (source)

Environmental flow & fish

• During the 1929-31 drought, Okanagan River downstream requirements were not met and ‘flows fell to zero at times’ - the record’s defining environmental-flow fact (PRESENT + ZERO, not merely absent data). [High] (source)
• In a succession of drought years there is not enough water to keep Okanagan Lake within its normal range and simultaneously supply downstream Okanagan River requirements; managers must either draw the lake below normal low water or reduce river releases. Minimum releases at Oliver were intended to include allowances for sockeye salmon migration through Osoyoos Lake and up to Vaseux Lake Dam - but in consecutive drought years these fishery flows ‘may have to be reduced.’ [High] (source)
• The 1929-31 sequence anchors the modelled fish-flow conflict: the Okanagan sockeye run (one of only two substantial runs left on the Columbia system) and the Okanagan Lake shore-spawning kokanee are both stressed when drawdown/low flows coincide with spawning; deep drawdown can leave kokanee eggs high and dry while low winter flows expose sockeye eggs. Sockeye flow targets at Oliver (e.g. 8.5-28.3 m3/s migration; 9.9-15.6 m3/s spawning) ‘may have to be reduced’ in two or more consecutive drought years such as 1929-31. [High] (source)
• Direct documentation of fish kills, stranding counts, or kokanee/sockeye population mortality specifically during 1929-31 was NOT located; the fisheries impact is inferred from the documented zero flows and unmet fishery-flow requirements rather than a contemporaneous fish-mortality record. [Moderate] (source)

1992 shows a different face of drought. The hydrological severity is real and well sourced, but the on-the-ground municipal record is almost entirely absent (a pre-digital-news year). What survives is the environmental-flow and fish signal.

Environmental flow & fish

• 1992 was a high-water-temperature, low-discharge year in the Okanagan River. Adult Okanagan sockeye migration into the river is blocked when mainstem temperatures exceed ~21 C; the 1992 passage record at Zosel Dam (downstream of Osoyoos Lake) shows the polymodal, stop-start migration pattern (intervals of near-zero migration followed by secondary peaks) characteristic of thermally blocked and delayed runs. Such high-temperature/low-flow delay is associated with increased prespawn stress and mortality. [High] (source)
• The autumn-1992 / winter-1993 record-low lake levels bear directly on shore-spawning kokanee: the 1974 Plan drops Okanagan Lake to secondary/February targets to avoid stranding shore-spawned kokanee eggs, and drought years force the largest drawdowns, raising egg-dewatering/stranding risk. Okanagan Lake shore- and stream-spawning kokanee stocks were in serious decline through the early-to-mid 1990s, though the retrieved sources do not isolate a 1992-specific kokanee kill or egg-loss figure. [Moderate] (source)
• Environmental-flow shortfall mechanism: under the 1974 regulation Plan, in consecutive drought years fishery (non-consumptive) flows in the Okanagan River ‘may have to be reduced’ below the September-October guideline band (approx. 9.9-15.6 m3/s) so that February-1 flood-control targets are met, meaning EFN releases are the first casualty in a drought such as 1992. The retrieved documents describe this as the governing rule rather than reporting the exact 1992 release deficit. [Moderate] (source)

What we could not find: contemporaneous municipal or quality-of-life reporting for this year. This is a pre-digital-news year, so the surviving record is hydrological and fisheries-based. Absence of record is not the same as absence of impact.

2003 is not one of the lake-elevation analog years, but it is the benchmark severe drought of the modern Okanagan, the year later droughts (like 2009) are compared against, and it shows drought and wildfire compounding.

Local government & infrastructure

• The Okanagan Mountain Park fire (Kelowna area) caused approximately $200 million in damage and destroyed 239 houses, per the province’s Firestorm 2003 Provincial Review; province-wide, Firestorm 2003 interface fires forced evacuation of over 45,000 people, destroyed over 334 homes plus many businesses, and the total cost to BC was estimated at about $700 million. [High] (source)
• The fire’s direct firefighting/response cost is given as $33.8 million (distinct from the ~$200 million total damage estimate), and it burned 25,912 hectares. Response mobilized 60+ fire departments, about 1,400 Canadian Armed Forces troops, and roughly 1,000 forest firefighters plus multiple air tankers. [High] (source)
• The fire destroyed 12 of the 18 historic wooden Kettle Valley Railway trestles in Myra Canyon and damaged 2 steel trestles/bridges. The KVR in Myra Canyon had been designated a National Historic Site shortly before the fire; federal and provincial governments jointly funded reconstruction at a budget of roughly $15 million, with all timber trestles and the two steel bridges rebuilt and the site fully reopened by 2008. [High] (source)
• The District of Summerland declared a state of emergency during the 2003 drought, indicating municipal-level water-supply crisis response in the Okanagan that year. [High] (source)
• Post-fire rains on the burned Okanagan Mountain watershed triggered debris flows and increased sediment loads in creeks draining into Okanagan Lake, degrading water quality through elevated turbidity and nutrient inputs, a recognized drinking-water and infrastructure concern for downstream systems. [Low] (source)
• The Filmon Provincial Review produced 42 recommendations (18 on fire prevention and mitigation), directly shaping subsequent local-government interface-fire and emergency planning across BC including the Okanagan. [High] (source)

Quality of life

• The Okanagan Mountain Park fire forced a mass evacuation of the Kelowna area, reported as roughly 27,000 residents (Wikipedia) up to 33,000 (Firestorm 2003 Provincial Review); the range reflects different source counts for the same event. [High] (source)
• St. Hubertus Estate Winery (established 1928) was destroyed along with the owner’s home and its entire 2003 crop, and many other Okanagan wineries lost crops to smoke taint, a direct agriculture/livelihood loss. [High] (source)
• Tourism during the peak season fell an estimated 30% to 50% below normal as a result of the fire, hitting the Okanagan visitor economy. [Moderate] (source)
• Recreation infrastructure was destroyed or compromised: six marine campgrounds were destroyed, and the Crawford mountain-bike trails and the Kelowna Crags rock-climbing area were compromised. [Moderate] (source)
• Wildfire smoke produced a measurable public-health impact: in the Kelowna region, physician visits for respiratory diseases rose between 46% and 78% above 10-year mean rates for three weeks during the 2003 fire period (peer-reviewed study using BC Medical Services Plan billing data); no similar effect was seen in less-exposed Kamloops. [High] (source)

Environmental flow & fish

• 2003 was a pivotal environmental-flow/fish-management year for the Okanagan: the Fish/Water Management Tool (FWMT), an internet-accessible modelling system to set weekly Okanagan Lake Dam releases balancing flood, drought/irrigation, and sockeye protection, was developed and implemented in 2003-2004, and a conservation-based sockeye hatchery program was initiated in 2003. [High] (source)
• Prior to the 2003-era interventions (adult fish passage re-engineering, side-channel construction, Skaha Lake hatchery outplants, and real-time fish-water management), Okanagan sockeye smolt-to-adult survival was only 1% to 3%, versus 7% to 25% afterward, underscoring the poor pre-2003 baseline these EFN tools addressed. [High] (source)
• Okanagan Lake Dam releases govern Okanagan River flows and the survival of sockeye eggs and young downstream, while the lake’s autumn drawdown must be managed so kokanee do not spawn too high on the gravel shoreline; a low-water drought year like 2003 tightens this trade-off between lake targets and downstream flow needs. [Moderate] (source)

2009 is the drought that reshaped local water governance: the year staged watering restrictions and basin drought planning became standard practice.

Local government & infrastructure

• The South East Kelowna Irrigation District (SEKID) implemented Stage 2 watering restrictions: lawn watering limited to two days per week, no watering between 10:00 a.m. and 6:00 p.m., and bans on washing sidewalks/driveways/parking lots, dust-control watering, washing buildings, and flushing roof gutters. [High] (source)
• SEKID cut farmers’ annual water allotment by 20 percent, with the board of trustees retaining the option to discontinue (shut off) service for non-compliance. SEKID supplies up to 85 percent of its water to farmers. [High] (source)
• SEKID’s McCulloch Lake reservoir (East Kelowna water source) sat at roughly two-thirds of its average level; storage was projected to potentially fall from about 9,000 acre-feet to 1,800 acre-feet. A 17-year camp host called it the lowest he had ever seen it in June. [High] (source)
• Westbank and South East irrigation districts restricted customers to sprinkling two days per week, with an escalation path to a single day per week and then a complete outdoor sprinkler ban. [High] (source)
• Glenmore-Ellison Improvement District reservoirs were reported at 20 percent below normal filling capacity. [High] (source)
• Releases from the Okanagan Lake Dam at Penticton ran well below normal at four to six cubic metres per second since January, reflecting deliberate holding-back of water through the dry season. [High] (source)
• Average daily per-capita water consumption in the Okanagan was cited at 400 litres (contrasted with a 140-litre Australian government target), underscoring supply-management pressure on local utilities; the Okanagan has the lowest per-capita availability of freshwater in the country per Statistics Canada. [High] (source)

Quality of life

• Residential/domestic users across affected districts were held to lawn watering just twice a week under drought restrictions. [High] (source)
• Growers were asked to cut water use by 20 percent; those needing to upgrade irrigation equipment faced substantial cost (orchardist Nick Kiran estimated $60,000-$70,000 for ten acres), which many could not afford given low returns. [High] (source)
• The Okanagan’s wineries and fruit crops were reported as threatened by the water shortage, attributed to low rainfall and a smaller snowpack (June 10, 2009 media coverage). [Moderate] (source)
• Recreation was directly affected: Coyote Cruises had to cut its Penticton Channel inner-tube float course in half due to low water levels. [High] (source)
• The extreme dry conditions coincided with a major wildfire episode: on July 18, 2009 three wildfires (Glenrosa, Rose Valley, and Terrace Mountain) broke out around West Kelowna during extremely dry, windy conditions; over 20,000 people were evacuated and the Terrace Mountain fire burned roughly 9,877 hectares. [High] (source)
• A heat wave with highs in the high-30s Celsius and a campfire ban accompanied the early-August peak of the drought; the Environment Minister urged residents to avoid car washing, lawn watering and long showers. [Moderate] (source)

Environmental flow & fish

• Inflow to Okanagan Lake in the first six months of 2009 was the sixth-lowest since record-keeping began in 1921 and was explicitly worse than the 2003 drought year. [High] (source)
• Inflows to Okanagan Lake were 39 percent of normal between November 2008 and May 2009, and 44 percent of normal in April/May 2009 (Des Anderson, BC environment ministry). [High] (source)
• Okanagan Lake was about 48 cm below full pool on June 9 (roughly one-third of a metre below normal for the time of year), even at its seasonal peak, constraining the water available to meet downstream flow needs. [High] (source)
• Sockeye salmon recovery was at risk: the largest sockeye run in 50 years returned to the Okanagan River in fall 2008, with young salmon rearing in Osoyoos Lake; low water levels threatened managers’ ability to release sufficient flows in late August/September to relieve the downstream temperature/oxygen ‘squeeze’ (Howie Wright, senior biologist, Okanagan Nation Alliance). [High] (source)
• Okanagan Lake Dam releases were held at only four to six cubic metres per second since January - well below normal - which directly governs Okanagan River flows and downstream sockeye egg/fry survival. [High] (source)
• Mission Creek, the main tributary to Okanagan Lake, was so low that parts of its course were dominated more by rocks than water, indicating tributary/spawning-habitat stress. [High] (source)

2015 was a watershed for drought awareness in BC. It is not a lake-elevation analog for today, but it is a significant Okanagan drought and a catalyst for the province’s modern drought-response framework.

Local government & infrastructure

• On Aug 5, 2015 the entire Okanagan Region was elevated to Drought Level 4 (the maximum), and the Province urged all water users - municipal, agricultural, industrial - to maximize conservation and to ensure water intakes were properly screened as levels dropped. [High] (source)
• OBWB and the Province stated that a 30% reduction in use by all Okanagan water purveyors would have a meaningful effect; individual utilities responded (e.g., Penticton reduced irrigation by 30%, RDOS called for a voluntary 30% reduction), with multiple communities implementing Stage 1-2 restrictions. [High] (source)
• Okanagan Lake dam operations required continued releases to meet licensed downstream (Okanagan River) needs even as the lake tracked ~15 cm below its Sept 1 target, illustrating the tight regulation margin (~1 m operating room) during the drought. [High] (source)
• By late September the Okanagan drought rating had eased back to Level 3 (some streams still flowing low), and the Board credited good management of stored water for helping the valley weather the drought. [High] (source)

Quality of life

• The 2015 fire season was far above normal: 916 fires had burned in BC by July 3, compared to the 10-year average of 537, coinciding with the Okanagan drought. [High] (source)
• Major August 2015 wildfires struck the south Okanagan/Boundary: the Testalinden Creek fire south of Oliver reached 1,566 hectares and the Wilson’s Mountain Road fire north of Oliver 317 hectares, together forcing evacuation of 371 homes; the nearby Rock Creek fire destroyed roughly 29-30 homes. [High] (source)
• The Rock Creek wildfire (east of the southern Okanagan) destroyed about 29 homes and additional structures and forced hundreds of evacuations; it was reported as human-caused. [Moderate] (source)
• Residents faced water restrictions and local watering bylaws under the Level 4 rating, with the Province directing residents to observe local water bylaws; recreational angling on Okanagan-area streams was closed, removing a summer recreation activity. [High] (source)
• At Level 4 the Province warned that further declines in stream, lake and aquifer levels could lead to water shortages affecting people, agriculture, wildlife and fish stocks; specific 2015 Okanagan agricultural/orchard/vineyard loss figures were not documented in retrieved sources. [Moderate] (source)

Environmental flow & fish

• Angling was suspended on the Okanagan River main stem (between Okanagan Lake and Osoyoos Lake) effective Aug 6, 2015 to protect fish stressed by high water temperatures and low flows; the closure order was set to run through Sept 30 but the river was reopened to angling as of Sept 16 as conditions cooled. [High] (source)
• Broader drought fishing closures covered the Similkameen drainage and the Kettle/West Kettle Rivers (effective Jul 15-Sep 15, 2015) plus streams across Wildlife Management Units 8-2 to 8-7 and 8-12 to 8-14, to protect fish vulnerable to low flows and high water temperatures; lake fishing remained open. [High] (source)
• DFO warned that low water levels and warm water temperatures were associated with severe stress and early mortality of migrating salmon; the Okanagan sockeye fishery was in very poor condition and closed to recreational fishers during the summer. [High] (source)
• The 2015 South Okanagan sockeye run - forecast to be one of the largest in recent history - collapsed under drought conditions: return estimates were cut to roughly 18,000-47,000 fish, with warm water and low levels causing physical stress, open wounds and fungal infection in migrating salmon and prompting cancellation of recreational/commercial sockeye fisheries. [Moderate] (source)

2021 is the clearest recent drought and the template for how a modern Okanagan drought propagates through all three lenses at once.

Local government & infrastructure

• The Province declared Okanagan Drought Level 4 (second-highest on the 0-5 scale) on Saturday, August 14, 2021; at Level 4, water licence holders not served by local water utilities were asked to reduce water use by half, and the Province warned regulatory action under the Water Sustainability Act was possible if conservation targets were not met. [High] (source)
• The Okanagan was escalated to Drought Level 3 (severe) in early-to-mid July 2021, with water users asked to reduce consumption and licence holders drawing directly from the large lakes or the Okanagan River channel asked to conserve. [High] (source)
• The City of Kelowna moved its water-utility customers to Stage 1 residential watering restrictions in summer 2021 (effective mid-July, ~July 12) in response to an unprecedented dry spring and hot early summer; this was Kelowna’s first activation of watering restrictions in several years. [Moderate] (source)
• West Kelowna moved to Stage 2 water restrictions on July 20, 2021 due to drought conditions, tightening residential watering rules for its utility customers. [High] (source)
• Okanagan Lake is managed under the provincial Okanagan Lake Regulation System (dam at Penticton) against a provincial-federal agreement that sets 340.4 m as the ‘lowest desirable’ level; in December 2021 the lake sat at 341.51 m, ~35 cm below the prior December, illustrating the drawdown pressures on the regulation system during the drought. [High] (source)

Quality of life

• Record drought and heat forced closure of nearly all Okanagan rivers and streams to recreational angling effective on/about August 11, 2021 through September 15, 2021, covering Management Units 8-1 to 8-15 and 8-21 to 8-23 (Christina Lake, Grand Forks, Osoyoos, Oliver, Penticton, Keremeos, Princeton, Summerland, Peachland, Kelowna, Vernon, Cherryville); lakes stayed open. Many waters recorded 25-30 C, and anglers were advised to avoid waters above 20 C. [High] (source)
• The late-June 2021 heat dome (valley temperatures approaching ~43 C) scorched and scalded Okanagan tree fruit; by June 29, 2021 the provincial production-insurance program had received 31 notices of loss from Okanagan tree-fruit growers (plus 50 from Lower Mainland berry growers), with apples showing sunburned leaves and scalded fruit. [High] (source)
• Kelowna and Vernon recorded their driest spring on record in 2021, and the Okanagan recorded exceptionally low (record-dry) soil moisture as the drought worsened - context for residential watering restrictions and agricultural stress. [Moderate] (source)
• Recreational fishing was banned in many Okanagan rivers and streams because of low flows and high temperatures, though fishing remained allowed in small and large lakes; the closures reduced summer angling/recreation opportunities across the valley. [High] (source)

Environmental flow & fish

• An early-February 2021 drawdown of Okanagan Lake (begun to reduce spring flood risk given an above-normal snowpack) prematurely exposed shoreline kokanee spawning areas; provincial sampling found 75% of kokanee eggs and alevin dead within the ~25-cm vertical drawdown zone. The Okanagan Nation Alliance had warned the government the predicted fry-emergence date was ‘too early,’ and the Province paused the drawdown in early March after impacts became apparent. [High] (source)
• The kokanee egg/fry die-off was especially damaging because it followed a record shore-spawner return in 2020 of ~316,000 fish (214% of the 10-year average, the best return since the 1970s); BCWF (via a Freedom of Information request) and director Jesse Zeman warned the setback to restoration could last ‘years, if not decades.’ [High] (source)
• A field biologist survey summary reported that roughly three-quarters of kokanee spawners’ offspring in the surveyed area were killed by the drawdown, with most kokanee observed still in the (dead) egg stage. [High] (source)
• During the July-August 2021 heat, Okanagan River water temperatures exceeded ~23 C, halting sockeye salmon migration; angling closures were imposed in part to reduce stress and post-release mortality on fish already stressed by low flows and high temperatures. [Moderate] (source)
• By December 2021 Okanagan Lake had fallen to 341.51 m - ~35 cm below the prior December and near the low end of its regulated range - though still ~1.1 m above the 340.4 m lowest-desirable level; government stated it did not expect harm to fish spawning habitat at that level. [High] (source)

2023 was the peak of the current multi-year drought and one of BC’s worst drought years on record, the year drought, wildfire, and a municipal water-system emergency struck the central Okanagan at once.

Local government & infrastructure

• The Province moved the Okanagan basin to Drought Level 5 (highest on the 0-5 scale) in mid-August 2023, asking residents, industry and businesses to reduce water use wherever possible and observe all watering restrictions, and directing water suppliers with upstream storage to follow release schedules to protect downstream flows. The basin was returned to Level 4 on October 5, 2023. [High] (source)
• During the McDougall Creek wildfire, the City of West Kelowna imposed Stage 4 water restrictions (no outdoor water use) to conserve supply for firefighting, issued a Do Not Consume Order for the Rose Valley water system area (except Sunnyside/Pritchard), and a Boil Water Notice for the Sunnyside/Pritchard system. [High] (source)
• West Kelowna’s new $75-million Rose Valley Water Treatment Plant (about $41 million federal/provincial funding via the Clean Water and Wastewater Fund), then in its final construction phase, was successfully defended from the McDougall Creek fire; Fire Chief Jason Brolund stated all structures were left standing. The plant later opened in November 2023. [High] (source)
• The McDougall Creek fire burned the watershed around the Rose Valley reservoir, the source water for more than half of West Kelowna residents, contaminating the source with sediment, nutrients, metals and organic matter from burned material and making the water persistently harder to treat; the Rose Valley Water Treatment Plant building itself was not damaged. The Do Not Consume Order was downgraded to a Boil Water Notice for the Rose Valley-Lakeview service area by August 30, 2023, then to a Water Quality Advisory by September 22, 2023. [Moderate] (source)
• In August 2023 the Province issued Water Sustainability Act fish-population protection orders in the North Okanagan (Salmon River and Bessette Creek), requiring water users including farmers to cease irrigation (effective on/about August 15, 2023) to protect threatened salmon; these orders expired September 30, 2023 in alignment with the standard April 1 to Sept. 30 irrigation-licence period. [High] (source)

Quality of life

• The McDougall Creek wildfire (started August 15, 2023 near West Kelowna, final size 13,970.4 hectares) destroyed homes across multiple communities: about 70 homes in West Kelowna, 20 on Westbank First Nation, 3 in Kelowna, 2 in Lake Country, and roughly 100 in the unincorporated lakeside communities of Traders Cove and Wilson’s Landing (including the historic Lake Okanagan Resort), with 303 structures impacted in total. No deaths were reported. Insured losses exceeded C$480 million. [High] (source)
• The fire forced mass evacuations: as of August 19, 2023 at least 35,000 people were under evacuation orders and another 30,000 under evacuation alerts across West Kelowna and Kelowna; a provincial state of emergency was declared August 18, 2023, and Kelowna International Airport suspended flights on August 18. [High] (source)
• Wildfire smoke drove severe air-quality impacts across the Okanagan in August 2023: the Ministry of Environment and Climate Change Strategy issued smoky-skies bulletins / air-quality advisories for the Okanagan, Shuswap, Similkameen, Nicola and Columbia regions, and at times Okanagan air quality was ranked among the worst in the world. Health guidance warned of elevated risk for older adults, pregnant women, infants, children and people with respiratory conditions. [Moderate] (source)
• Drought, extreme heat and the August wildfires abruptly ended the 2023 Okanagan tourist season and stressed vineyards, with wildfire smoke exposing grapes to smoke-taint risk; winemakers who had hoped to offset a weak vintage with tasting-room sales were undercut by the wildfire disruption. [Moderate] (source)
• The 2023 BC grape crop saw an estimated 54% loss with financial losses pegged at about C$133 million (per a June 2023 industry report), with 45% of vines suffering long-term damage and 29% needing replanting. This loss was driven primarily by a late-December 2022 cold snap and compounded by 2023 drought, extreme heat and wildfire smoke; it is a BC-wide figure heavily concentrated in the Okanagan. [Moderate] (source)

Environmental flow & fish

• The August 2023 Level 5 declaration was explicitly triggered by fish stress: many fish-bearing Okanagan streams were at historical low flows with several completely dry, and stream water temperatures reached levels described as lethal to fish. Water suppliers with upstream storage were directed to follow release schedules to maintain minimum downstream flows. [High] (source)
• To protect threatened salmon during the 2023 drought, the Province used Water Sustainability Act fish-population protection orders in North Okanagan tributaries (Salmon River and Bessette Creek), restricting water withdrawals and irrigation from mid-August 2023 until the orders expired September 30, 2023. [High] (source)
• The Osoyoos Lake sockeye population (Okanagan Basin sockeye, managed with the Fish and Water Management Tool deployed in 2004) has exceeded its long-standing escapement goal of 35,500 in 12 of the 20 years from 2004 to 2023, per DFO’s escapement-goal review; this frames the stock context but is not a 2023-specific return count. [Moderate] (source)
• On the transboundary Osoyoos system, the IOLBC Fall 2023 update reported Osoyoos Lake operating within its normal (non-drought) rule curve in 2023 (winter band 909.0 to 911.5 feet, Nov 1 2023 to Mar 1 2024), with levels dropping below historical averages only in October; no formal Osoyoos Lake drought-year operational variance was invoked in 2023 in the retrieved records (documented Zosel Dam drought variances are dated 2024, 2025 and 2026). [Moderate] (source)