Estero clean-up project in UP community - Philippines

I assume estero is estuary but I've not had luck finding a translation...
http://manilastandardtoday.com/2015/01/03/estero-clean-up-project-in-up-community/

"The estero running through Block 5 in Daang Tubo (a community inside the UP Campus) is on its way to being clean.

GMA Network and its partners, the Philippine Mine Safety and Environment Association, the Philippine Biochar Association and the Sagip Ilog Pilipinas, collaborated on the Clean River Zone Biochar Community initiative.
The Kapuso Network and its partners signed a Memorandum of Agreement in early 2014 to clean up the said estero using bokashi balls (bokashi balls are made from dried mud and other organic materials, including biochar, and are used to clean bodies of water that have high concentrations of sludge and slime)." ...