Toshka Project Impacts on Water Levels and Discharges

Toshka Project is one of the major and national irrigation projects planed to increase the cultivated areas in the south valley, improve the opportunity for better jobs and increase the income for the country. The project impacts and consequences should be studied carefully to maximize the intended benefits and reduce any expected side effects. This paper is proposed to study the effect of the full operation of the project on the water levels and discharges down stream High Aswan Dam. This paper is considered a continuation for the author work to estimate the effect of low water levels on Irrigation pump station. The author has shared in previous work to estimate the effect of low water flow on pump station. On the other hand, this paper is focused on the effect of operating Toshka Project on this pump station. It is considered one of the first papers to discus this important subject. During this research, pump stations, for irrigation purposes, along the River Nile from Aswan to Cairo were reviewed according to their design and critical water level to determine the potential for expected problems due to passing low discharges in the four studied reaches from Aswan to Cairo which are Aswan-Esna, Esna-Naga Hammadi, Naga Hammadi-Assiut, and Assiut-Cairo. A one-dimensional computer program based on solving the flow equations was developed to compute water levels related to the analyzed discharged. The model was developed using Visual Basic Computer language and then calibrated using the actual water level readings from gauging stating after developing the corresponding rating curve for each station. The computed water levels were compared to the design and critical pump station water level to determine the adequacy of the water level for pump station supply. The frequencies of different discharge were evaluated and the probability of the analyzed discharges was evaluated. Different flow cases were considered during this analysis and the resulted water level and discharge changes were highlighted. Conclusions and recommendations were presented as well.