Evaluation of the Existing situation of the sewer system of Qalqilia city And design of the northern part of the city
Qalqilia is a Palestinian city located close to the Green Line in Palestine it serves as the administrative centre for the Qalqilia Governorate. Like all parts of Palestine, it has a Mediterranean climate moderate heat in summer to cold winter. This moderate climate is one of the factors attracting people to this city, in addition it reflections in a positive way on agriculture summer and winter ,on fruit trees, natural vegetation, livestock.
Qalqilia city has one of the highest rates of population growth in Palestine in recent decades .This is due to the migration of thousands of residents of nearby villages after the catastrophe of 1948. Now with about 48,000 capita and 8500 house connections have a present demand of clean water, which exceeds 4.0 MCM i.e. 200L/C/D.
When the sewer system was designed in the Intifada period there was no sufficient financial resources to meet the amount of sewer and rainfall water .Another problem, is that in winter season the channels around the city is closed and this lead to cumulate the water in the city .Also flooding the rainfall on agricultural fields happens especially in the western areas.
Also the northern area of Qalqilia has a normal urban expansion. At the current situation there are only few houses in this area and they are connected with small pipe diameters. So the existing sewer pipes in the northern part can't handle the future load.
So it is very important to solve the problems of overload on the northern area and this can be achieved by designing a suitable sewer network for this active area.
In order to achieve the above objectives, the following steps must be done:
1) Collect the data which include contour map, roads layout, building distribution, water consumption rate, water resources, and population and growth rate.
2) Study the existing situation of the wastewater network and the problems in this network.
3) Analyses the future needs.
3) Design the suitable sewer network for the northern part of Qalqilia using Sewer CAD program.
In this project the sewer network for future (30yrs) is analyzed and designed for the northern part of Qalqilia. All the pipes of UPVC material are used with 4-12 in diameters are needed. The number of manholes needed is 143. All the results are within the limits. All the conduits meet the limitation of slopes in the network (between1%-15%), the covers between (1-6) m, and the velocity between (0.6-3) m/s .