How Much Water Does an Almond Tree Need? Gallons, Inches

A California almond orchard needs about 47 inches of water a year to meet full crop demand, and growers statewide report applying about 36 inches on average, according to the Almond Board of California water footprint factsheet. In gallons, that is roughly 1.28 million and 0.98 million gallons per acre. At an example 120 trees per acre, each tree gets about 8,100 to 10,600 gallons a year.

These numbers move with tree age, soil, weather and region. This guide shows how much water an almond tree needs by age and by place, how growers in California and Australia cut it, and what a UC trial measured when water was held back on purpose. Use the calculator to turn your own acreage, tree count and yield into gallons per tree and per pound.

How much water does an almond tree need?

There are two useful numbers. One is what the tree could use if soil water is never short (crop evapotranspiration, or ETc). The other is what growers actually apply, which is lower. The factsheet does not say why; rain, stored soil water and lighter irrigation may all play a part. The table below puts both side by side for a California orchard.

*Our arithmetic: one acre-inch is 27,154 gallons, divided by an example 120 trees per acre. Divide by your own tree count. The 47 and 36 inch figures are statewide from the Almond Board of California factsheet (April 2018), where the 36 inches is the average growers report through the California Almond Sustainability Program. The Sacramento Valley rows come from a University of California drought guide by Terry Prichard, (2001), which gives about 37 inches for an average year of full water use in the northern Sacramento Valley and 27 inches for one deficit-irrigated orchard near Chico (2000 data).

Regions probably differ. The California Water Impact Network, an advocacy group, says most almond acreage lies south of the Delta, where an acre can need up to 4 acre-feet a year; the Prichard figure above is for the northern Sacramento Valley. The chart puts the figures, and a UC trial near Orland, on one scale.

Chart

Almond water per year, by source

Inches per year; each bar is a different measure, so read the label

Gallons per tree, per day and per pound

Per day, the answer depends on the month. Almond water use starts when leaves open and climbs as the canopy fills and the weather warms, so July uses far more than March. As a plain average, 8,100 gallons spread over the roughly 240 days from March to late October is about 34 gallons per tree per day. Peak summer days are well above that and spring days well below. This is arithmetic from the figures above, not a measurement.

Per pound of kernels, a UC trial gives a measured figure. In 2006 on a 320-acre microsprinkler ranch in a CARDIP trial using the Orland CIMIS station, the fully irrigated plots used about 450 gallons of irrigation water per pound of nutmeats, and the deficit plots about 490, according to the CARDIP almond report by Shackel, Fulton, Krueger and Lampinen. Over the three years of the trial the averages were 537 and 522 gallons per pound.

That is close to the well-known per-almond figure, though the measures differ. With kernels of about 1.1 grams in the 2006 harvest, a pound holds roughly 410 nuts, so 450 to 490 gallons per pound is about 1.1 to 1.2 gallons of irrigation per almond. The three-year averages of 537 and 522 gallons per pound, with heavier kernels of about 1.2 grams, work out to about 1.4 gallons. The Almond Board’s 2018 California analysis puts the blue (irrigation) water footprint at 1.7 gallons per almond. The Almond Board describes the oft-repeated figure as 1 gallon to grow a single almond, and says that by the same water footprint measure a head of lettuce takes 3.5 gallons, a walnut 5 and a hamburger 660 (Almond Board of California, Water Wise page). Water per almond is a measure of efficiency, not of how much the orchard takes in total.

How water needs change as the tree grows

A young orchard uses much less than a mature one, so the 47 inch figure does not apply to a block planted three years ago. The University of California handbook on irrigating young orchards gives a rough share of mature ETc by tree age: 40% in year one, 55% in year two, 75% in year three and 90% in year four. Trees usually move from non-bearing to bearing around year three, and the handbook says young almond water use changes quickly from year to year and within one season.

Chart

Young almond water use as a share of mature ETc

Percent of a mature tree’s crop evapotranspiration, by tree age

The handbook also gives the method for a single tree: take the mature ETc from a nearby weather station or a local weekly report, multiply by the age share, then by the row and tree spacing. Check the result against soil moisture or tree stress readings before you trust it.

Why almond orchards use so much water

An almond orchard is a deep-rooted, full-canopy tree crop that is irrigated through a long season. In the Central Valley the season runs from bloom in February to harvest in late summer, and the hottest, driest weeks are when the nuts are filling. A leafy canopy in hot, dry air loses a lot of water to evapotranspiration, and the tree must replace it.

The Almond Board says almond trees use around the same amount of water as other California fruit and nut trees such as pistachios, walnuts and peaches. Nut trees need slightly more than fruit and vegetables because making protein takes more energy, and so more water, than making sugars. The orchard also sits in a Mediterranean climate with a dry summer, so rain covers only part of the demand. In its 2018 factsheet the Board says the 1.7 gallon blue water footprint per almond from its California analysis rests on an average of 47 inches, described as the maximum applied to grow healthy trees, while growers report irrigating with 36. The older 1.1 gallon figure came from a global average.

Scale matters too. The California Water Impact Network, an advocacy group, used 1,563,000 acres and 3 to 3.5 acre-feet per acre to estimate that almonds use 4.7 to 5.5 million acre-feet a year, or 14% to 17% of the state’s developed agricultural water. The Almond Board’s own Land IQ survey (November 2025) puts total acreage at 1,505,997 acres in 2025, down from 1,525,638 in 2024, the fourth straight yearly drop, so the acreage behind those totals is now smaller.

Five ways growers cut almond water use

None of these needs new equipment on day one. Start with the first, because every other step depends on knowing how much the orchard really uses. Check the label of any product you apply through the system, follow local water rules, and ask your farm advisor or irrigation district before changing a schedule.

1. Schedule by evapotranspiration

The most widely recommended method in California is to calculate ETc from reference evapotranspiration (ET0) and a crop coefficient (Kc) that changes through the season, according to the CARDIP report. Weather stations report ET0 daily, and UC Cooperative Extension offices publish weekly ETc reports for almonds. Divide by your system efficiency to get the amount to apply.

Satellite-based ET now adds a block-by-block view. OpenET gives 30-metre, daily evapotranspiration data. A USGS-hosted study of California almond orchards, Knipper and co-authors (2024), found the OpenET ensemble matched applied irrigation plus rain to within 13% on monthly data across 148 orchards. It also found the models struggled with the sharp drop in water use when growers stop irrigating before harvest, so treat it as a check on your schedule, not a replacement.

2. Measure the tree, not just the weather

Soil moisture sensors and a pressure chamber, which measures midday stem water potential, show whether the tree is short of water. The Almond Board lists soil moisture meters and precision scheduling among the tools behind its water goals. The point is to catch over-watering as well as stress: a sensor that shows wet soil at depth is a reason to skip the next set.

3. Use regulated deficit irrigation, with care

Hull split is the stage when the green hull opens. Cutting water during part of it can reduce hull rot, and a UC trial measured the savings. The next section gives the numbers. Prichard’s 2001 drought guide warns that stress is most harmful early, from bud break through fruit set, and that stress affects the following season’s crop as well.

4. Keep the water in the root zone

Over 80% of California almond farms use microirrigation, nearly twice the rate for California farms overall, and the Almond Board says the water used per almond fell 33% between the 1990s and the 2010s. In 2018 the industry set a goal of a further 20% cut by 2025, and by 2022 growers had reached three-quarters of it. In Australia, 95% of orchards are on drip systems managed with soil moisture monitoring, according to the Almond Board of Australia as reported by Good Fruit and Vegetables (September 2020). Fixing leaks, flushing lines and checking pressure keeps that efficiency from slipping.

5. Match water to tree age and block

Young blocks, shallow soils and sandy corners dry out at different rates. Irrigate young trees by the age share in the table above and split large orchards into blocks with their own sets. Each block can then follow its own readings instead of the average.

▶ Seven green farming technologies, ranked, including ways to save water. · 2:24

Regulated deficit irrigation: what a UC trial measured

From 2004 to 2006, UC researchers ran a large test on a microsprinkler-irrigated ranch in a CARDIP trial using the Orland CIMIS station. Control plots got normal grower practice, close to full ETc. Deficit plots were stressed on purpose during hull split, to a midday stem water potential of -14 to -18 bars. In 2006 the control plots applied 35.1 inches and used another 6.5 inches from soil storage, 41.6 inches in all. The deficit plots applied 30.4 inches and drew 5.6 from soil, 36.0 inches in all.

Yield was 2,200 pounds of nutmeats per acre in the control and 1,880 in the deficit plots in 2006. The authors found that difference was not statistically significant, and nut size and moisture were not affected. For 2006 they estimate a saving of about 5 inches of tree water use (about 13%), and about 15% in 2005. They also note that the yield gap was biggest in the third year and that carry-over effects need more years of data. The orchard had shallow, variable soil and a leaf spot problem, so another site could give different results.

Earlier work cited in the same report found that dropping to 50% of ETc during part of hull split reduced hull rot. The gain depends on soil depth, so the saving at your site could be smaller or larger.

Chart

Water used in one UC almond trial, 2006

Inches, 1 March to 26 October, CARDIP trial, Orland CIMIS station

Almond water calculator

Enter your own numbers below. The starting values are examples only, set near the 36 inch grower average and the yield from the UC trial, and are not a forecast for your orchard. The water price is an example; use today’s price from your district or supplier.

Try the numbers for your own farm below.

What satellites and sensors can and cannot tell you

Satellite maps help most when an orchard is large and uneven. Vegetation index maps show which blocks have thinner or weaker canopy than their neighbours, and ET data show how much water the canopy is using. Neither tells you the right amount to apply. That still comes from ETc, soil moisture and tree stress readings.

Farmonaut Satellite + AI Farm Monitoring System draws vegetation maps for the blocks you outline, so you can see which blocks look different from their neighbours before you walk the rows. Treat it as a way to decide where to check first. The walkthrough video shows how to read the maps.

▶ A 20-minute walkthrough of reading satellite crop monitoring maps. · 19:36

Almond water use around the world and the rules

Australia’s almond industry reports higher water use than California’s average. The Almond Board of Australia figure, reported by Good Fruit and Vegetables, is 12 to 14 megalitres per hectare on mature orchards. That converts to about 47 to 55 inches a year (1 ML per hectare is 100 mm), compared with 36 inches reported in California. Climate, rainfall in the growing season and what is counted as applied water all differ, so the two do not compare one for one.

In California, the Land IQ numbers show orchard removals continuing, about 49,197 acres in 2025. Whatever the region, a lower water bill and a lower pumping cost both come from the same step: know the orchard’s real water use by block and season. Water prices vary widely by district and year, so use today’s price from your supplier, not an old average.

Related pages on our site: almond and walnut water use, almond water use per pound, irrigation systems for different terrain, aquifer depletion and groundwater recovery, almond pollination risks, weather data for farm planning, farm vehicle and equipment tracking, crop traceability records, farm carbon footprints, crop loans and insurance, farm administration tools and farm data for developers.

FAQ

How much water does an almond tree use per day?

It depends on the month and the tree’s age. Averaged over about 240 days, a mature California tree that gets 36 inches a year at 120 trees per acre uses about 34 gallons a day. Summer peaks are higher and spring days lower. Young trees use 40% to 90% of mature ETc in years one to four (UC handbook).

How much water does an almond farm use per year?

Per acre, about 36 inches is the grower-reported California average, or around 0.98 million gallons. A 100-acre orchard at that rate applies about 300 acre-feet. In Australia, mature orchards use 12 to 14 megalitres per hectare, which is about 47 to 55 inches.

Why do almond trees require so much water?

They are a large, leafy tree crop with a long season, a dry summer and nuts that are rich in protein, which the Almond Board says takes more water to make than sugars. The Almond Board says their water use is close to that of other California nut and fruit trees such as walnuts, pistachios and peaches.

How much water does it take to produce one almond?

The Almond Board calls 1 gallon per almond an oft-repeated figure, and its 2018 California analysis gives 1.7 gallons of blue (irrigation) water. A UC trial measured 450 to 540 gallons of irrigation per pound of kernels, which works out to about 1.1 to 1.4 gallons per nut at the kernel weights in that trial.

Can an orchard cut water use without losing yield?

Sometimes. A UC trial saw about 5 fewer inches of tree water use and no significant yield loss when stress was held to -14 to -18 bars during hull split, but yield was lower in one year and the authors asked for more data. Stress before fruit set can cut the crop, so check with your farm advisor first.