Civil engineering projects have many impacts in environment sustainability. The purpose of this research is to evaluate the human consequences of civil engineering building activities on the natural habitats of gorillas and chimps in the Deng Deng National Park, in particular, and Cameroon in general. An indirect census based on single-pass nest counts was used to estimate ape density at Deng Deng National Park. Data were collected at the various field trips during 3 months. The line transect was the most efficient and reliable census method. It has been used in many studies concerning the estimation of ape population density. This method consisted of making observations along the centre line of the transect. The principle was based on the assumption that the probability of detecting a nest decreases. The identification of consequences entailed listing all important environmental components that were likely to be affected. According to the study's findings, the number of nid sites and population density of great crested newts rose in the Deng Deng National Park to 80 sites, 391 nids, and 0.80 ind/km2. The Lom Pangar hydroelectric dam has had significant ripple effects on the distribution of great apes in general and particularly on the density of chimps. The study finds that, despite habitat fragmentation, the population of large singes has increased significantly in the Deng Deng National Park.