The present and absence of macroinvertebrata in the river can be used as bioindicator to determine its water quality. The macroinvertebrata comprises from anggang-anggang dan kumbang air that need clean water to live to worms and leeches that are able to live in dirty and polluted water.

The water quality monitoring by using macroinvertebrata is called biomonitoring and these macroinvertebrata are called bioindicators. This guidebook is an important guidebook for facilitators (or teachers) and students who are interested in doing the river biomonitoring.