COUNTRY PAPERON

REUSE OF LOW QUALITY WATER IN EGYPT

Agriculture Drainage System

The total agriculture land amounts to 8 million feddan

The implementation of the National Drainage Program started in 1970. It included the widening and deepening of the existing main open drains, the excavation of new main drains ,the construction of new pumping stations and the rehabilitation of old ones.

It included also, the installation of subsurface drainage systems of laterals and collectors The average field drainage depth is 1.35 m and the minimum depth of water levels in the main drains is 2.5m.

The total target of the surface drainage is 7.2 million feddan, of which 4.9 million feddan are in the Nile Delta and 2.3 million feddan in Upper Egypt.

Agriculture drainage Reuse

The drainage water in Upper Egypt is pumped or flows by gravity back to the Nile. In the Delta, the network of open drains discharges their flows mainly into the Northern Lakes or the sea. The total length of Nile Delta drains is over 16,000 km long.

Three types of reuse practice can be distinguished: natural, official and non-official reuse

Natural reuse of drainage water occurs where rivers or canals act as a drain for hydrologic basin aquifer systems. Natural reuse is largely non-controllable except by modifying the amount of recharge that occurs, i.e., reduction of deep percolation from irrigation

Official reuse is the practice of including part of drainage water flow in the quantity of irrigation water delivered by the irrigation system. Physically, official reuse occurs through lifting specific amounts of drainage water from drains and blending the water with higher quality canal or river water. Official reuse may also include extracting moderately saline groundwater for supplementing irrigation water supplies.

Non-official reuse is practiced by individual farmers who decide when and how much drainage water will be used for supplementing their irrigation water supply

Reuse as a Policy

Dr. Mahmoud Abu Zied, Minister of Water Resources and Irrigation, Egypt; stated that” In terms of increasing the overall system efficiency, the drainage reuse pays back much faster and at much less cost than the irrigation improvement. This justifies the adoption of the drainage reuse strategy on the short term”

National Agriculture Projects that depend on the reuse of drainage

water. The purpose was to use as much drainage water as possible especially for the irrigation of large land reclamation projects in the eastern and western parts of the Delta.

Three projects of this kind were designed

AL-SALAM CANAL PROJECT

Al-Salam Canal is designed to be fed from the Damietta Branch upstream of Farskour Dam with fresh water while supplemented with drainage water from the Lower Serw pumping station and Bahr Hadous drain near its outfall. At this point, the drain contains the collection of drainage water from all the catchments served namely Nizam , Beni-Ebeid and Erad .

The average yearly discharge of the Lower Serw pumping station is about 600 x 106 m3, and that of Bahr Hadous drain is about 2 x 109 m3. These bring the available drainage water total to 2.6 x 109 m3 / year.

The average salinity measured at Lower Serw pumping station is around 1 000 ppm, and that measured at Bahr Hadous outfall is about 1 400 ppm. The weighted average of both waters is 1300 ppm. When this is mixed with fresh water at a ratio of 1:1 the salinity of the mixture is expected to be in the neighborhood of 800 ppm which is reasonable, given that the water is going to be used for the irrigation of sandy soils.

OMOUM DRAIN PROJECT

The canal serves an area of reclaimed lands of about 500,000 fed. and passes a discharge of 5.0 x 109 m3 / year. The quantity of drainage water to be used in the project is about 1.0 x 109 m3 / year and has an average salinity of 1 800 ppm. The expected salinity of water after mixing will be in the margin of 800 ppm.

Drain No. 1 and 2

Those drains are located on the far north of the Middle Nile Delta region

The collective discharge of the two pumping stations is about 900 x 106 m3 / year at an average salinity of 1000 ppm

Following the completion of the construction of the above three projects, an extra quantity of 3.40 x 109 m3 of drainage water will be used for irrigation which brings the total to 7.60 x 109 m3 (4.2 x 109 m3 are already re-used every year at different other drains in western / eastern / middle delta and Fayoum).

current status of reuse of drainage water Reuse of Drainage Water in the Nile Delta During 1995/2003

Year Eastern Delta

Middle Delta

Western Delta

Total Reuse

Q

(mcm)

EC Q

(mcm)

EC Q

(mcm)

EC Q

(mcm)

EC

1995-96

1745.91.891814.61.79705.91.424266.31.77

1996-97

1843.21.941947.91.85642.51.314433.61.81

1997-98

1736.31.661801.31.77632.41.354170.11.66

1998-99

2126.91.482168.31.52738.31.075033.51.43

1999-00

1661.81.641891.41.641183.61.974736.81.72

2000-01

1830.21.571958.81.761058.31.924847.31.72

2001-02

2026.51.742199.81.671062.81.765289.11.71

2002-03

2329.32.002082.41.90875.61.765287.41.92

Treatment Technology

The total quantity of reused treated wastewater in Egypt was about 0.7 BCM in 1995/96 of which 0.263 BCM is biologically treated while the rest (0.437 BCM) is only primary treated. The quantity of the reused wastewater is approximately 10% of the potable water consumption

Potential of Treated Sewage Reuse

In Greater Cairo, there are six wastewater treatment plants, with a total capacity of approximately 27 million m3/day. All of which will eventually be treated to a secondary standard. With a current combined treatment capacity of this quantity of effluent is potentially sufficient to irrigate about 100,000 feddans

Drainage water quality criteria for irrigation purposes in the Nile Delta,

Egypt

Salinity of drainage water(dS/m)

Restriction on use for irrigation

< 1.0used directly for irrigation

1.0 – 2.3mixed with canal water at ratio 1:1

2.3 – 4.6mixed with canal water at ratio 1:2 or 1:3

> 4.6 Not used for irrigation

Maximum Possible drainage water reuse in Nile Delta

(mcm)

RegionAvailable Drainage Water

Currently ReusedPossible to be reused

Eastern Delta 4083.652049.891519.02

Middle Delta5849.142007.732881.06

Western Delta3819.151123.562384.33

Total13751.945181.186784.41