The assessment of environmental impacts associated with existing and new water-level and flow control structures is becoming increasingly important these days. This study investigates the effect of water level control structures on the self-assimilative capacity of a river as well as other environmental impacts like the effect on fish habitat. A computer assisted model is developed to predict the change in the waste loading capacity of the river as well as its water quality, taking the dissolved oxygen as the main criteria, as a result of the change in its hydrologic and hydraulic regime. The model comprises four modules: (I) a hydraulic sub-model to simulate the change in the depth and velocity along the river as a result of the water-level control structure, (ii) a water temperature sub-model to simulate the change in water temperature, (iii) a water quality sub-model to simulate the change in water quality, taking the dissolved oxygen and the biochemical oxygen demand as the main parameters, and (iv) a fish habitat sub-model, where certain sub-reaches of the river are studied for their suitability as fish habitat. In order to quantify the changes that the river under goes due to the construction of a water-level control structure, several indicators are sought. These indicators provide quantifiable measures of the change in the self-assimilative capacity of the river as well as its water quality and the suitability, or lack of it, as a fish habitat. The model is applied to a real life case study, i.e., the 170 km long Nile River reach upstream of the Esna-Barrage. For the sake of comparison, the model is also applied for the same reach before the construction of the control structure, i.e., a free-flowing river reach of the same length and geometry. Several hydrologic and waste loading conditions are applied for the sake of simulating all the possible cases. The analysis utilizes the above mentioned indicators in showing that the river lost from 15 % up to 80% of its loading capacity depending on the conditions applied. The results also showed a depreciation in the river's water quality ranging from 2 % to 40 %, again depending on the hydrologic and loading conditions applied. Finally, the effect on fish habitat showed a decrease of7% of the areas suitable as fish habitat.


School of Sciences and Engineering

Date of Award


Online Submission Date


First Advisor

Emad Hamdy Imam

Second Advisor

Salah El Haggar

Committee Member 1

Salah El Haggar

Committee Member 2

Abdallah Bazaraa

Committee Member 3

Mostafa Foda

Document Type



162 leaves

Library of Congress Subject Heading 1

Hydraulic structures.

Library of Congress Subject Heading 2

Water levels


The American University in Cairo grants authors of theses and dissertations a maximum embargo period of two years from the date of submission, upon request. After the embargo elapses, these documents are made available publicly. If you are the author of this thesis or dissertation, and would like to request an exceptional extension of the embargo period, please write to thesisadmin@aucegypt.edu

Call Number

Thesis 1997/71



Included in

Engineering Commons