As it is an autobiography, we have to use first person narrative. A model can be given. It was on the day before independence , I was born but nobody cared about my existence till I became chubby during the great monsoon showers of 2002. My mother Gangotri was sure about the surplus rain which we were going to receive during the monsoon. She was quite happy then. She told me that all the wastes that humans have dumped on me can be given back during the showers. I was quite surprised ! How is it possible? I was playing with the pebbles which lied at my shore. Suddenly, sky began to change its colour . Darkness loomed every where. Heavy rainfall began to shower everywhere in the surroundings. I saw my body becoming larger and larger. I was overwhelmed with joy . I began to cruise with extreme power and happiness. The plastics and garbage which suffocated me was thrown aside . I saw humans crying all the way I passed . Many boats were collapsed . I was like a thunder … After four days the rain began to lose its power. But the body I gained remained with me for four months. My water filled body became enormous. But after that incident, I became skinny . For 2 years there was no rain. Now I am just a thread like water body. Filled again with garbage. I don’t know when will I become extinct. But I know one fact It will rain soon. Because mother nature won’t leave me desperate to die.
This is just a model. Usage of personal figures in a personal language is considered as a good manner in writing autobiographies. We need to instill human emotions when we have to write about non living substances like river etc