Yakima Valley is the odd entry on this site's water list, and deliberately so: unlike every other profile here, this water's real significance to brewing has almost nothing to do with mashing or beer chemistry, and everything to do with hop agriculture — this irrigation-basin region in Washington State grows a large share of the hops used in American brewing, and the water covered here is what irrigates the hop fields themselves rather than water any brewery mashes with.
A soft-to-moderate profile behind a genuinely different kind of brewing relevance
The figures for Yakima Valley's water: calcium 24 ppm, magnesium 8 ppm, sodium 5 ppm, sulfate 12 ppm, chloride 6 ppm, bicarbonate 40 ppm. Numerically this sits in soft-to-moderate territory, not far from San Francisco's own municipal profile — but the comparison that actually matters here isn't against another brewing city's mash water, it's against how consistent, well-managed irrigation affects the hop plants themselves. Hop cone chemistry (alpha acid development, oil content, overall yield) depends on a growing season's full water availability and timing, not on any single mineral reading the way a brewer's mash water does — this profile describes the input to agriculture, not to a boil kettle.
Why this region became the centre of US hop growing
The Yakima Valley's combination of a long growing season, the specific latitude and daylight hours hop bines need to develop properly, and reliable irrigation from the water this page describes made it a natural centre for American hop cultivation, producing a large share of the hop varieties named throughout this site's hop reference — American high-alpha varieties in particular owe their consistent commercial availability substantially to this region's growing conditions. That's a genuinely different kind of "water shaping beer" story than any other profile on this site tells: not a city's tap water shaping a local style directly, but an agricultural region's irrigation water shaping the raw ingredient supply an entire national brewing industry depends on.
Using this profile
There's no meaningful brewing-salt adjustment to make from this page the way there is for the mash-water profiles elsewhere on this site — this figure isn't something a homebrewer replicates in a kettle. Its real value is context: understanding that the hops named on this site's hop reference pages didn't just appear, they were grown somewhere specific, under a specific water and climate regime, and that supply chain is worth knowing about for anyone curious how a bag of pellets or a bale of whole cones actually gets to a homebrew shop shelf.