Industry currently uses about one tenth of the island's water (the vast majority still goes to agriculture). But as Taiwan builds new science parks and expands existing ones, more of the small island's water will go to industry – mostly to make semiconductors and steel.

The priority on semiconductor manufacturing development in Taiwan is not purely economic. Taiwan's global prominence as the top maker of the tiny silicon chips that go into all of the world's high-tech devices is seen by experts as a deterrent against hostile actions from neighboring China, making protecting the sector a national security issue.

Taiwan's semiconductor plants build the tiny computing chips that go into our iPhones and fighter jets and cars. Those same plants need huge amounts of water and power to etch and deposit tiny bits of metals and chemicals on silicon wafers.

To limit its water use, TSMC started began constructing its own water recycling plant in 2021 – another drought year - and it and many of Taiwan's biggest chip factories are cutting down water use by an average of 10 percent – unfortunately at a time when global demand for chips is growing.

"We need to be more smart," says Gene You, a civil engineering professor and water management specialist at National Taiwan University. He says Taiwan is being too accommodating to chip factory expansion, because it generates economic growth. "From my observation the policy is just, 'what you need we will give you, because the economy needs you,'" he said. "I don't think that is a good way [to manage water]."

Many of Taiwan's cities are also limiting residential water use at night by reducing water pressure during certain hours. The hardest hit areas in the island's south are cutting tap water off for two days each week.

But Yang, the tomato farmer, believes that when faced with tough choices, Taiwan should prioritize its farmers in addition to its lucrative semiconductor factories.

"A country needs to rely on its own food supply. It is a form of security. We cannot import everything we eat," says Yang.

Taiwan has an unlucky combination of factors: heavy seasonal rains but very little reservoir storage capacity because of Taiwan's mountainous and sediment-heavy topography. That leaves the island heavily-dependent on frequent typhoons and storms to replenish water supplies.

Water authorities have tried cloud seeding – dispersing small particles in the sky – to stimulate rain and set off flares near reservoirs in an attempt to attract precipitation, all to no avail. Authorities have also been dredging reservoirs, removing sediment accumulation so the reservoirs can store more water in the future.

However, those efforts are in vain if rainfall remains low. Just how long water rationing lasts depends on whether April and May bring the so-called plum rains — seasonal storms that come during the plum harvest.

Lin Qingshu, a third generation plum farmer in Tainan county, does not think those rains will come. Her fruit orchards rely entirely on rainfall levels, and with few storms passing through, "our plums this year will be stunted" — they won't grow to maturity. "They bloomed plentifully but there is no water," she said.

She surveys what is left of the Zengwen reservoir, its low water levels ringed by a thick band of white – parched dry land left as the water recedes.

"Coming up myself and seeing the reservoir, I can see the situation is really severe. It hurts my heart," she sighs.

It sprinkled a few days ago and Lin says she was so hopeful, she nearly cried.

"Us farmers have a saying that we look at the sky for sustenance," she explains – meaning their livelihoods depend on good weather. In this case, that means a good rain.

Hugo Peng contributed to this report.