6.0 Identified Water  
   Supply Problems









Rock Hunting







Banjos, etc.


Village of Baoma, Sierra Leone












































































































































Dry season low flow

Near the end of the dry season the flow from the diorite bedrock springs falls to near zero.  If the fracture flow interpretation of groundwater circulation is correct, then the steeper hydraulic gradient that exists at the end of the wet season and into the dry season drives groundwater to discharge at the diorite bedrock spring vents at a higher rate than during the dry season.  As a result, relatively more water is taken from the more heavily contaminated Garden Spring towards the end of the dry season.


All of the Baoma springs show evidence of bacterial contamination, and the degree of bacterial contamination is believed to vary from the wet season to the dry season.  No analyses for individual pathogenic bacteria has been performed, but it is interpreted that the Garden Spring is more likely to behave as a vector for transmission of human pathogenic bacteria than the diorite bedrock springs.


Shock chlorination is occasionally used at the Habbour Spring catchment.  An unknown quantity of chlorine in the form of chlorine tablet(s) is interoduced into the spring catchment, which has a volume of approximately 1,700 gallons.  The resultant concentration of chlorine is unknown and is likely insufficient to provide effective disinfection.

Some villagers boil spring water, which may be the most effective disinfection practice that is currently in use.  However, the cost of charcoal for this purpose is significant and cost is a disincentive to the use of disinfection by boiling.

Some villagers disinfect spring water by point-of-use chemical addition.  One such home disinfection system was inspected and it is believed that the amount of disinfectant that is aded to each 5-gallon bucket of water is insufficient to provide effective disinfection.

Inadequate disinfection is believed to be widespread.  An informal health survey of villagers indicates that water-borne disease is commonplace, and varies from the dry season to wet season.

Source area protection

Although its flow rate is substantial, the Garden Spring is an undesirable water source for drinking water.  Many of the villagers who use this water either disinfect the water by boiling or else use a chemical disinfectant.  The cost for charcoal to boil the Garden Spring water is significant, and the use of disinfectants appears to be irregular and likely ineffective at times.  Because the Garden Spring is located immediately downgradient from the village, it is not likely that source water protection will be effective at this spring.  Land development upslope from the Habbout, Kamera and Motema diorite bedrock springs is slight, and specific source area protection measures are in place at the Habbour Spring. 

Land development has begun in the ridge-top area to the south of the West Side Spring, and this source source may eventually suffer a similar pollution load to that of the Garden Spring.

Source Sufficiency

The population of Baoma is believed to be on the order of 600 individuals.  A preliminary survey of water use indicates that the average, dry season water use may be on the order of from 5 to 10 gallons per day (gpd).  Assuming that these figures are reasonable, the daily water demand during the dry season is on the order of from (600 people x 5 gpd) = 3,000 gpd to (600 people x 10 gpd) = 6,000 gpd.  Assuming an average daily demand of 5,000 gpd, this demand could be met by a minimum flow of (5,000 gpd / 1,440 minutes/day) = 3.5 gpm if the flow is captured into non-leaking system storage. 

 System Storage

The springs issue water constantly, and spring water that is discharged during off-peak and night-time hours is not collected deliberately, although some incidental storage does occur in the small, leaky cement spring catchments and in transmission pipelines.

Lack of system storage results in water supply insufficiency during the morning and evening peak demand periods.



Chronic leakage                           Substandard pipe installation

The present system of delivery of water to private homes and to tap stands by shallowly-buried plastic pipe results in leakage and/or loss of much of the water that is collected from the springs.  Water delivery is often interrupted by leaks and the need to take the water system off-line while the leaks are being repaired.  Because the water systems are generally unable to maintain a cash reserve to meet emergency needs or to stockpile water system parts and supplies, the water systems are often off-line longer than may be necessary.


Many villagers have the attitude that water should be free.  This attitude may come from village life in the interior provinces, where the population density was significantly less than in Baoma, and where little or no measures were taken to manage water sources.  The situation is very different in Baoma, where a relatively high population density needs to obtain water from a limited number of sources.

Some of the villagers are unable to pay money for water services.  It may be useful to identify specific "in-kind" tasks that these villagers can routinely perform to support the operation of water systems in lieu of cash payments.



More about the hydrogeologic setting of Baoma

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