Three sources provide insight into population trends of Western Grebe, but all have notable limitations. The Christmas Bird Count (CBC) may provide the broadest coverage of the population, but trends for Western and Clark's Grebes are analyzed jointly. Because Western Grebe is more numerous, the large long-term decline in the Western/Clark's Grebe trend suggests that there has been a large decrease in the continental population of Western Grebe, but it cannot be quantified, and it does not distinguish between the Canadian and the larger American breeding populations. 

The only other long-term data source is the Breeding Bird Survey (BBS), which has medium coverage and precision, and is not optimal for detecting colonially nesting waterbirds. However, that limitation has not changed over time, allowing for medium reliability overall. The Canadian BBS trend shows little change, with current abundance 26% above the level it was at in 1990 when data began to be recorded separately for Western and Clark's Grebes. Although reliability of trends at the regional scale is mostly low, it appears that there has been a moderate increase in the southern Prairies, a moderate decrease in the northern Prairies and parkland region, and a large decrease in southern British Columbia. 

The British Columbia Coastal Waterbird Survey (BCCWS) also provides some data, but over an even shorter period and limited to the portion of the population wintering along the southern British Columbia coast. The BCCWS shows a very large decline of 96% between 1999 and 2018, but this may at least in part reflect a southward shift of wintering distribution rather than a change in population abundance (Wilson et al. 2013). Overall, although the BBS trend is the most reliable, confidence in the status of little change is low because of other evidence suggesting a decline, and the lack of data prior to 1990.

The goal for Western Grebe is to remain at or above its average population level from 1970 to 2022, based on the Breeding Bird Survey. Recent data show that the population is within its goal range. This is largely consistent with the objective in the Species at Risk Act's Management Plan for Western Grebe, which aims to maintain the breeding population between 31,000 and 34,000 adults from 2022 to 2032, over a breeding distribution of at least 830,000 km².