The Gambia is a small West African country of 10.700 km2, with an estimated population of 2,6 million. The country is surrounded by Senegal. As its name indicates, it is located on the lower stretch of the Gambia River. In the Gambia, the Gambia River is nearly at sea level, which makes it vulnerable to seawater intrusion. Water is saline up to 250 km from the mouth of the river, which corresponds to the western half of the country, where most of the people live.
The salinity of surface water makes the Gambia particularly dependent on fresh groundwater, which is found at shallow depth throughout the country. Sustainable groundwater management is therefore a priority, and active measures are required to prevent anthropogenic contamination, over-abstraction or seawater intrusion into the aquifers.
National groundwater monitoring network of the Gambia
Since 2014, the Department of Water Resources of the Gambia operates a groundwater monitoring network of about 35-40 observation boreholes. Most of the observation boreholes are equipped with automatic data loggers. Nearly half of the monitoring boreholes are concentrated in the capital city area, where the population density and industrial activity is the highest, while the rest are equally distributed eastward at 35 km distance throughout the north and south bank of the country.
Data sharing in the GGMN
Groundwater level data, groundwater quality data and borehole data are collected and managed by different units, across different ministries. The same goes for surface water data and meteorological data. Data sharing is therefore necessary for efficient water management. However, the plan to set up a national information system has not yet materialized and data sharing remains a challenge.
In order to move forward, the division in charge of the groundwater monitoring network has decided to share the data in the GGIS, the Global Groundwater Information System, an online platform operated by IGRAC where hydrogeological maps, borehole data and groundwater monitoring data can be shared and made accessible to all, for free. The groundwater monitoring data from the Gambia have been accessible since 2018.