Garcia street Merritt BC

Highways entering 5&5A

The Nicola River was the quiet partner draining the Nicola Valley to the coast from the conjuction of the Coldwater bad boy of 2021. The enterence to the city from the north end includes two highways shared with the Nicola river. A dance partner that sustained a lot of damage that took years to repair…

The Nicola River:

Tributary of Thompson River

is an important tributary to the Thompson River in south-central British Columbia. The section from the outlet of Nicola Lake to its confluence with the Thompson River near Spences Bridge covers a distance of approximately 100 kilometers.Here is some general information about the river’s flow and levels in this stretch:General Flow Characteristics * Regulation: The flow out of Nicola Lake is regulated by a storage dam, which influences the river’s initial discharge. * Tributary Influence: As the river flows towards the Thompson, it is significantly augmented by major tributaries, most notably the Coldwater River (near Merritt) and Spius Creek. These tributaries, particularly the Coldwater River, contribute large volumes of water, especially during spring melt. * Annual Pattern: Like many interior BC rivers, the Nicola River experiences a typical pattern: * Maximum Flows (Peak Flows): Generally occur in the late spring or early summer (May/June) due to snowmelt, and are the basis for flood events. * Minimum Flows (Low Flows): Typically occur in the late summer, fall, and winter. Low flows can be a critical concern for fish, particularly salmon, due to reduced habitat and increased water temperatures. Drought conditions can exacerbate these low-flow periods.Flow Rate DataExact, long-term historical maximum, minimum, and annual mean flows vary considerably along the river and depend on the specific monitoring station (hydrometric station) and the period of record. However, some data points are available for reference: * Near the Outlet of Nicola Lake: The drainage area is approximately 2,990 \text{ km}^2. *

At the Thompson River Confluence (Spences Bridge):

The total drainage area of the Nicola River is approximately 7,670 \text{ km}^2. The discharge here is much greater than at the lake outlet due to the contributions of major tributaries. * One study mentions a designated (daily) flow of 380 \text{ m}^3/\text{s} at the downstream limit of a study area, which indicates the scale of potential high flows near the confluence. *

Critical Low Flow for Fish: MAD

Photo KDG returning Salmon circa September 2025

For salmon management, thresholds like the 20\% Mean Annual Discharge (MAD) and 10\% MAD are used to indicate flows below which fish may be negatively impacted. For a station on the Nicola River (near Nicola), the 20\% MAD was noted as 1.4 \text{ m}^3/\text{s} and the 10\% MAD as 0.678 \text{ m}^3/\text{s}.Maximum and Minimum Levels * Maximum: The Nicola River has a history of significant flood events. The November 2021 flood, for example, was described as a 200-year flood event, which severely impacted the river’s channel and surrounding communities like Merritt.

* Minimum:

Low water levels are a recurring environmental concern, especially in the late summer and early fall, driven by both natural climate cycles and water abstraction for uses like agricultural irrigation.For the most precise and up-to-date data on daily and historical maximum/minimum levels and flows, it is best to consult the Environment and Climate Change Canada’s Water Survey of Canada or the British Columbia River Forecast Centre, which maintain continuous monitoring stations (like 08\text{LG}065 at the Outlet of Nicola Lake and 08\text{LG}070 south of Shackan).

Recovery from flash flood of 2021

The Coldwater River flooded very quickly and did a lot of damage in November of 2021. It joined the Nicola River at the confluence of highway 8 and continued to do its contribution to a 200 year flash flooding that did extensive damage to the coquihalla highway in many places in the province. Not many lives were lost, however economic damage was tremendous.