What type of planning did the early river valley cities use?

They used a city-based plan  with social classes and  proper drainage and sanitation.

The town dwellers were  divided into various classes. The rich and the ruling class lived in multi-roomed spacious houses and the poorer people lived in small tenements. Public buildings and big houses were situated on the streets while the modest houses were situated on the lanes. Encroachment on public roads or lanes by building houses was not permitted.

Most of the houses had baths, wells and covered drains connected with street drains.  There were underground drains for the streets. These drains were covered by stone slabs. The soak pits were made of bricks and the house drains were connected with road drains.