The Colombian department plans to spend some US$46mn this year on water and sanitation works, US$20mn more than in 2018.
Floods caused widespread damage and a dozen deaths earlier this week.
The US$1bn plant will treat 70% of Bogotá's wastewater plus 100% of that from the Soacha distrct.
Established through a partnership between Catholic Relief Services and IDB Lab, the FideAgua trust fund is managed by development bank Bandesal.
Drainage looks closer to be installed in vulnerable coastal cities.
The fund has outlined a conservation plan entailing US$118mn in investments by 2030.
The Chinese government has donated 10 water tankers to serve San Salvador, and has announced plans for future donations for the water and sanitation service.