(i) Irrigation System : The French started building canals and draining lands in the Mekong delta to increase cultivation. The vast system of irrigation works-canals and earthworks was built with forced labour. (ii) Infrastructure : They also built roads, railways to increase trade and control the entire region. The Trans Indo-China rail network linking north and south parts was built. (iii) Infrastructure for plantation : Rail and port facilities were set up for rubber plantations which were owned by French.