PONTIANAK, TheKabarNews.com—The Pontianak city administration is assessing the Biong area in neighboring Kubu Raya Regency, West Kalimantan, as a potential raw-water source. This follows a prolonged dry season that allowed seawater to intrude into the Kapuas River.

Pontianak Mayor Edi Rusdi Kamtono inspected the site in Kuala Mandor on Tuesday afternoon, September 22. He was accompanied by a laboratory team from city-owned water utility Perumda Tirta Khatulistiwa. The city published its initial findings the following day.

Biong lies along the Landak River, about 22 kilometers from the Penepat Reservoir. Its position farther upstream could make it less vulnerable to tidal saltwater intrusion than Pontianak’s existing river intakes.

“Biong is one alternative because the farther we move from tidal seawater, the fresher we expect the water to be,” Edi said in Pontianak.go.id.

An initial field test recorded a salt concentration of 11 milligrams per liter. However, the reading covers only one water-quality indicator and does not establish that Biong is ready to supply the city.

The assessment must still examine the river’s depth, flow and seasonal water quality. Officials also need to calculate the cost of pumping and transporting the water to Pontianak’s treatment system.

Edi said the city would evaluate whether it could build a pipeline linking Biong with the Penepat Reservoir. The administration has not announced a proposed route, construction budget or completion target.

The search has become more urgent as saline water moves farther upstream during the dry season.

On September 13, the city reported that the salt concentration at Penepat had exceeded 1,000 milligrams per liter. This disrupted the quality of water entering Pontianak’s treatment network.

The administration temporarily transported freshwater from Radak in the Terentang district by barge to support production.

The scale of the city’s water requirement makes a permanent alternative important.

Pontianak’s four principal intakes—Imam Bonjol, Nipah Kuning, Selat Panjang and Parit Mayor—support a stated production requirement of about 2,000 liters per second. Penepat can provide approximately 200 liters per second.

Because Biong is located in Kubu Raya and forms part of a wider river system, any infrastructure project would require coordination beyond the Pontianak administration.

The city has previously sought support from the provincial administration. It sought help from the Public Works Ministry’s Kalimantan I River Basin Agency, which manages the relevant water resources.

“We do not want to depend on only one source,” Edi said, adding that the city would subject every alternative to technical testing.

Biong therefore remains a candidate rather than a confirmed raw-water source. Laboratory analysis, hydrological monitoring and an engineering feasibility study will determine whether it can provide Pontianak with a reliable supply during future dry seasons.