Major Chinese bitcoin mining pools are each seeing daily hashrate drops of between 10% and 20% following continuous rainstorms in Sichuan.

China’s southwestern Sichuan province, a mountainous region that is estimated to have over 50% of the Bitcoin network’s total computing power, has been hit by heavy rainstorms since last week, which peaked over the last two days.

The heavy rainstorms have caused electricity outages in parts of the region as hydro-plants stop generating power to help discharge the floods. Some counties are also experiencing telecommunication and internet breakdowns, said Kevin Pan, CEO and co-founder of PoolIn.

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As result, impacted bitcoin mining farms in the region are forced to unplug from the network for the time being. It’s not clear when the situation will prove as the rainstorms are still ongoing.

Data from BTC.com shows the world’s top four bitcoin mining pools – PoolIn, F2Pool, BTC.com and Antpool, all based in China – have each seen their hashrates drop between 10% and 20% over the last 24 hours. The computing power connected to these four pools accounts for around 50% of the Bitcoin network’s total.

Pan said in a Weibo post Tuesday China time that in addition to mining farms being forced to unplug due to electricity and internet disruptions, some have also proactively paused operations ahead of time and evacuated their on-site staff for safety precautions.

According to the Xinhua News Agency, the accumulated rain volume in a dozen most-impacted cities in Sichuan between Aug. 10-15 alone has already surpassed the average August monthly volume in any year’s record.

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Further, one major highway that leads to Sichuan’s mountain area, where most of the mining farms are located, is shut down due to severe floods and mudslides.

Meanwhile, bitcoin’s last three-day and one-day average hashrate has dropped to around 123 and 110 exahashes per second (EH/s), respectively. These numbers are down over 3% and 10%, respectively, from the seven-day rolling average around 127 EH/s, which is still at an all-time high.

Read more: The 2020 Rainy Season Is Tougher Than Ever for China’s Bitcoin Miners

The monsoon season in China every year brings abundant rain and thus excessive hydropower resources especially in the country’s southwestern regions, including Sichuan and Yunan. Such energy excess leads to cheap electricity prices that have been attractive to bitcoin miners.