Irrigation Development in Ghana: Past experiences, emerging opportunities, and future directions

1. Introduction

Agriculture has a central socioeconomic position in Ghana. This sector accounts for about 65 percent of the work force, about 40 percent of the gross domestic product, and about 40 percent of foreign currencies acquired through exports. Although agriculture is a key part of the country's economy, the structure of the sector is vulnerable because it relies on rainfed agriculture during a roughly six-month rainy season. Droughts and other types of unseasonable weather pose risks for farmers. Under these conditions, irrigation development offers the promise of greater food security and the rural-area development by ensuring yearlong agricultural production.

Despite considerable potential for development and the emphasis placed on irrigation development in many plans, less than two percent of the total cultivatable area in Ghana is irrigated. Moreover, even within this small area, researchers lack a clear understanding of where in Ghana different types of irrigation infrastructure are used and to what effect. Less than a third of the estimated total irrigated land in Ghana lies within 22 well-known public schemes, and not enough is known of the location, development and management of the informal irrigation schemes that account for the remaining two-thirds of total irrigated land. Although donors and policymakers express interest in providing new funds for irrigation development, the lack of reliable data on where irrigation currently exists, trends in its development, and opportunities and constraints within formal and informal schemes undermines consensus about how to build on what already exists in the sector.

Ghana’s overall national goal is to attain a middle income status with a per capita income of US$1,0001 by the year 2015. The agricultural sector must lead in achieving this national goal, as agriculture employs more than 50 percent of the total economically active population (Kundell 2008). Agriculture in Ghana is predominantly practiced on smallholder, family-operated farms, which produce about 80 percent of total agricultural output. About 2.74 million households either operate small farms (most of themless than 2 hectares) or keep livestock (MOFA 2008). Cultivable land is still abundant as only 38.9 percent of total agricultural land area is currently cultivated. Yet productivity of existing farmland is generally low and uncertain, because of prevailing traditional low-input, shifting-cultivation farming systems and dependence on rainfall.

Ghana cannot achieve economic growth and poverty reduction targets without significant improvement in the agricultural sector (Kyei-Baffour and Ofori 2006). Growth in agriculture may be achieved both through extensification (putting more land under cultivation) and intensification (increasing the productivity of existing land). In most cases, irrigation is central to increasing productivity of existing agricultural land.

Ghana is endowed with sufficient water resources for irrigation-based intensification. Estimates of Ghana’s irrigation potential are wildly divergent, ranging from 0.36-1.9 million hectares to slightly more than 33,000 ha under irrigated cultivation (FAO 2005; Agodzo and Bobobee 1994).

Irrigation development in Ghana has been justified as a way to achieve (1) food security, (2) poverty reduction, and (c) rural employment. This argument is specifically related to the Northern regions, as they are characterized by mono-modal highly variable rainfall distribution.

Despite irrigation’s considerable potential and the emphasis placed on it in recent plans, the proportion of potential irrigable land actually under irrigation is insignificant. In addition, the performance and productivity of existing irrigation schemes, particularly those that were publicly developed, are generally low (GIDA/JICA 2004).

This study was initiated to develop an understanding of irrigation in the country, including the geographical distribution of various types of irrigation taking place, the nature and economics of crops under irrigated agriculture, the potential for development of various types of irrigation, and the key limitations to such development.

The study was seeking answers to the following pertinent questions:

• Besides the known public schemes, what other types of irrigation systems are there in the country? Where are they developed most and for what purpose are they used?

• What are the opportunities and constraints of the various irrigation typologies?

• How profitable are the irrigated agricultural production systems in Ghana?

• What policy conclusions or recommendations may be made to strengthen the irrigated agricultural sector?