Operational Drainage Water Reuse Guidelinesby

Shaden Abdel-GawadProfessor and Former President

National Water Research Center, Cairo, Egypt

Introduction

Given its current population growth rate and need for national food security, Egypt is forced to develop new lands for agricultural production. Coupled with the expansion of the agricultural land base is the need to provide an adequate irrigation water supply. This poses a serious challenge where Egypt has limited fresh water resources, depending mainly on the River Nile. Therefore Egypt has embarked on a water conservation program, which includes an Irrigation Improvement Project, and drainage water reuse. About 12 billion cubic meters of surplus irrigation water are collected in open main drains each year, but only about 6 billion cubic meters are currently being reused. Drainage water therefore, represents a valuable resource which can be utilized in agriculture to meet crop water demands. In the early 1970s, Egypt adopted a long-term plan to reuse drainage water for irrigation on a more sustainable basis. Obviously the reuse of drainage water for agriculture plays an important role in the Egyptian water resources strategy.

The reuse of drainage water may lead to serious salinization problem of soils unless careful water and salt management are considered. Drainage water may also contain highly toxic substances from agricultural pesticides or industrial and/or domestic wastewater discharged into the open agricultural drains, which may cause serious health problems. Chemical contaminants in the drainage water may bio-accumulate in the food chain and in the soil profile. In general, the reuse of drainage water in irrigation has the potential of causing serious problems of soil degradation, reduction in crop productivity and quality, and animal and human health hazards.

Also, the reuse of low quality drainage water for agriculture poses many human health and environmental challenges. Villagers, land owners and field workers are at risk by contamination of the drainage water, especially by pathogens, if they are in direct contact with the water. Pathogens may also accumulate on the irrigated crops, which will be a further human health hazard if these products are consumed directly without being properly washed or cooked.

The success of drainage water reuse in irrigation depends on minimizing the long-term impacts on soils, crops, environment and socio-economic conditions. This requires applying a package of good practices in managing drainage water and improving its quality. Therefore, guidelines are needed to assist the water users in using the drainage water in an environmentally safe manner.

Guidelines objectives

The purpose of developing operational guidelines is to assist landholders to adopt safe and effective practices for reusing drainage water for land reclamation and agricultural production of new lands. Also, it could help in determining how to reuse drainage water in an environmentally safe manner without exerting negative impacts on human health and the environment (soil, water and crops). The detailed objectives are;

Avoiding long-term degradation of crops and soil.

Protecting environmental quality and human health. Ensuring the social and economic wellbeing of the farmers.

The guidelines are targeted to landholders, extension personnel, GOE ministries and agencies, and NGO’s

Components of the Guidelines

To guarantee the success of the development of the Operational Guidelines, three main components were considered. Those are; the environmental component, where the reuse of low quality water for agriculture poses many human health and environmental challenges. Different parameters such as fecal Coliform and heavy metals should be identified in the drainage water and should be within the acceptable limits for safe irrigation. The primary emphasis was placed on the protection of public health and the secondary emphasis was on the impact of external elements in the water system on the crop production.

The second component was the agricultural component ; where using the drainage water in irrigation can potentially lead to problems of soil salinity, sodicity and soil contamination that can adversely affect the ability of soils to grow crops economically or of acceptable quality. So, the agricultural component of the guidelines could be used to enable the user to rate the salinity hazard factors and to suggest irrigation and crop management practices to overcome such hazards. These guidelines are intended for use on currently cultivated lands as well as on new lands being brought into production by reclamation.

The last component is the socio-economic component where the reuse of low quality water may affect negatively the social and economic conditions of the farmer's population. It is therefore important to define the socio-economic categories of the farmers, identify developmental constraints, and provide a list of institutions which can implement an appropriate policy and program interventions. The socio-economic component of the guidelines could be used to predict the degree of vulnerability of farmers who use drainage water for irrigation. In addition, these guidelines identify institutional measures which could be taken in order to mitigate the risks.

Process to Develop the Guidelines

The guidelines were built on an integrated platform comprised of agricultural, environmental and socio-economic components. The Guidelines development also benefited from inputs provided by stakeholders and farmers in the study area. The powerful of the Drainage Reuse Guidelines lies in the fact that it has been developed from 8 years of extensive field monitoring, data synthesis and integration, field testing, and stakeholder consultation and inputs.

Steps of guidelines development are as follows:

1. Pilot area selection

Three pilot areas were selected in south El-Hussania as part of the El-Salam Canal Command area based on different criteria such as: easily accessible, continuous presence of the landholder in the area, full cooperation of the landholders with the project and finally representative to different socio-economic beneficiaries categories.

2. Agricultural, Environmental and Socio-economic monitoring program

A major input to the Guidelines development was the data collected from the bio-physical, environmental and the socio-economic monitoring program undertaken in the three pilot areas from 1998 to 2006. The aim of the bio-physical monitoring program was to assess changes in water quality, soil quality, crop productivity and levels of pollutants due to drainage water reuse. Monitoring was also conducted to determine the status of land tenure and changes in land development. The socio-economic monitoring program aims to compile and assess changes in socio-economic conditions to support development and modification of policies and interventions to assist landholders to successfully and safely adopt drainage water reuse practices for land reclamation and irrigation.

3. Data analysis

Different analysis for different collected parameters were carried out to study the impact of using low quality water on agricultural and environmental items (soil, water and crop quality). Also, different analysis were carried out for socio-economic parameters using SPSS, to assess changes in socio-economic conditions such as farm level economics (cost and net return for different crops), quality of life and satisfaction level.

4. National and International Standards

The Operational Drainage Water Reuse Guidelines incorporate information from various national and international water quality standards such as FAO, WHO, Egyptian and Canadian water quality standards. Also, guidelines incorporate information from specialist reports and studies undertaken by local and Canadian Consultants, to develop water quality guidelines and human health practices for drainage water reuse

5. Logical Integrated Framework of the Operational Guidelines

The agronomic, socio-economic and environmental considerations are tightly integrated in the Guidelines structure, where there are primarily 5 logical steps to be followed in Guidelines application.

6. Testing the Operational Guidelines

Testing the developed guidelines was carried out on two different scales; small sale testing in demonstration farms and wider scale in pilot areas.

Small sale testingTo test the guidelines under restricted conditions, two demonstration farms were identified within south El Husseinia plain. The farm size is 5 and 12 feddans respectively. The sites were selected to be representative of the total area for soil, crops, and irrigation and drainage conditions. The operational Guidelines were successfully applied consecutively for both summer and winter seasons. The application of the guidelines showed that the high crop yield and the soil salinity reduction indicated that the developed guidelines are reliable and practical on the small scale farms.

Wide scale testing

Three new pilot areas were selected to test the developed guidelines in wide scale areas. One plot in each pilot area with a total area of 50 feddans was selected to test the operational guidelines in 2004 and 2005. The application of the guidelines showed that the rice crop yield reached 3.760 and 4.468 ton/fad for summer 2004 and 2005 respectively which is within the national average of rice yield in old lands (4-5 ton/feddans).

7. Computerization of the Operational Guidelines

A computerized version of the guidelines was developed to fulfill the needs of decision makers, researchers, engineers and extension specialists. It is available in both English and Arabic.