A view of Qingcaosha reservoir in Shanghai File Photo: VCG

Shanghai water authorities said that the city's tap water supply is normal, following saltwater inflows since early September.

The mouth of the Yangtze River has seen saltwater inflows since the first half of September, but the city's water supply companies have strengthened water quality monitoring, and have scientifically carried out reservoir operation and scheduling, so tap water production and supply are normal and the water quality is up to standard, according to the official WeChat account of the Shanghai Water Authority on Tuesday night.

The Shanghai water authorities said on September 24 that it has taken measures to secure water supply as two reservoirs, Qingcaosha and Chenhang at the mouth of the Yangtze River, witnessed repeated saltwater inflows on September 5 and 14.

Saltwater inflows are a common natural hydrological phenomenon at the junction of rivers and seas. When the flow of the upstream freshwater river is insufficient, the seawater will pour back into the estuary to form a salt tide.

Shanghai is located at the mouth of the Yangtze River, and saltwater inflows of varying degrees often occur from October to March, according to the local water bureau.

The water bureau said the saltwater inflows in the two reservoirs were caused by the continuous drought in Yangtze River Basin since August this year, and typhoons also made the situation worse.

The water authorities said on September 26 that the water supply companies have strengthened the monitoring of the mouth of the Yangtze River to know the trend of the salt tide in advance and had stored water before the saltwater inflows.

Shanghai, home to 25 million residents, had a total water consumption of 7.743 billion cubic meters in 2021, and this year's high temperatures led to an increase in urban water consumption. From June to August this year, the city's average daily water supply was 8.656 million cubic meters, an increase of 0.87 percent over the same period last year, according to caixin.com.