The Environment and development are not good bed fellows.The Thika super Highway project in Nairobi Kenya involved reconstruction of the Museum Hill round about that occurs above the confluence of Kirichwa 1 and 2 streams. Tributaries of the Nairobi river. The reconstruction of the round about involved disturbance of the stream`s basin and transportation of soil to and from the construction site. Environmental Impact assessment only concentrate mostly on visible aspects of projects. In this case this study was done on benthos in relation to sediment loading from the activities on the reconstruction of the round about was done in a bid to bring out what effect important development projects may have to micro aspects of the environment. aspects that may not be captured by Environmental Impact assessments and may as well have influence on the upstream, on location and down stream locations of a stream. Like The Kirichwa streams in this case.