The Development study on water resources development and management for Lake Kyoga Basin Final Report -Supporting- Chapter 4 Hydrogeology CHAPTER 4 HYDROGEOLOGY 4.1 Collection of Existing Data Existing data about hydrogeology managed by Directorate of Water Resources Management (DWRM) are Groundwater Database, Mapping Project data, and Groundwater Monitoring data. Others are the MIS database which is water supply facilities database managed by Directorate of Water Development, including the items of location, water source, functionality, and so on. 4.1.1 National Groundwater Database (NGWDB) This database was established by DWRM with contracting to a local consultant in 2000. DWRM had been compiled database based on the “Borehole Completion Report” which is submitted by drilling company after completion of drilling. In 1990s, it was managed by database software on MS-DOS, and before 1990s, it was borehole ledger described on paper book. Now it was compiled by Microsoft Access database management software on the Windows base again. Figure 4-1 shows the initial display of the database. The database has been input the data based on the completion report submitted by drilling company every year. It is including the well specification, geological information, pumping test data, water quality test result, and so on. This database is very sophisticated. DWRM gave to the study team the Source: DWRM data which are related to the Lake Figure 4-1 Initial Display of National Groundwater Database Kyoga Basin. In the obtained data, the number of data which described the registered well number is 11,880, the number of data which described the well construction information is 9,672, the number of data which described the hydrogeological information is 5,902, the number of data which described the pump information is 1,095, and the number of data which described the water quality is 2,293. However, the position data which is necessary for analysis have many mistakes. Some position data are input by Latitude-Longitude system, and others have UTM coordinates. Latitude-Longitude system were used in old data mainly. In this study, these data were used after correcting the position data to adequate position from referring to the location name, e.g. Sub-county name or parish name or village name. Problem of this database is as follows: 1) Borehole positions have many mistakes, 2) It is difficult to correct the administrative structure, 3) There are some duplicated data. 4-1 The Development study on water resources development and management for Lake Kyoga Basin Final Report -Supporting- Chapter 4 Hydrogeology 4.1.2 Groundwater Mapping Project DANIDA has supported this project. This is compiling several maps for districts about groundwater Status of Groundwater Resources Mapping in Uganda development. Now, in 47 districts in total, mapping was completed or is going on . In addition to NGWDB data, re-measurement of the ¹ position of borehole which was unclear in NGWDB was conducted, and shallow well and spring data were collected from district office in this project. Final results are providing useful maps for administrators of each district. Several kinds of maps are provided as follows; 1) Groundwater potential map, 2) Hydrogeological Legend characteristic map, 3) Groundwater Quality map, 4) lakes Districts with complete Groundwater resources maps Districts where groundwater resources mapping activities have been initiated Hydrochemical characteristic map, 5) Water sources Districts with draft groundwater resources maps location map, 6) Water coverage per parish map, 7) Source: DWRM Figure 4-2 Progress of Mapping Project Water services area and population density map, 8) Population per parish and distance to water source map, and 9) Water supply technology option map. However, Since data management of DWRM is poor, all data is not available even in published paper maps or digital data, now. MBALE DISTRICT Groundwater Potential Map 620000E i 630000E 640000E 650000E 660000E 670000E m u ko K on o ir T S : UTM, Zone 36 Grid : Transverse Mercator Scale 1 : 100,000 To Projection : Clark 1880 (modified) Spheriod : 33 deg. East of Greenwich Meridian of Origin LEGEND : Equator Latitude of Origin : 0.9996 Inferred Borehole Yields Scale Factor of Origin To Pallisa : 500,000m False Eastings (cubic metres per hour) : 10,000,000m a False Northings : New Arc (1960) Poor (0.01-0.5) s Datum i : Metre ll . Moderate (0.5-0.7) 130000N 130000N a Good (0.7-1) P Very good (>1) Sironko Water quality National park Above Guideline Values and below Maximum Acceptable Values (MAV) To Tor o ro [% Above Maximum Acceptable Values Infrastructure All weather tarmac road All weather murram road Dry weather murram road 120000N 120000N Motorable track Railway [%Main District Town a Administrative Boundaries y International boundary District boundary n County boundary e Subcounty boundary Parish boundary K f Water resources Rivers 110000N 110000N o Major permanent river Open Water o c Minor permanent river or i Permanent wetlands (papyrus) in main valleys or l T b u Seasonal wetlands in secondary valleys p e DATA SOURCES R Inferred borehole yields and water quality: Based on analysis of data from RUWASA and Directorate of Water Development ( as per May, 2001). Administrative boundaries, rivers, landcover and infrastructure: National Biomass Study proje 100000 100000N Location of Mbale in Uganda NOTE This map is to be used as a guideline for detailed groundwater investigations. The data density (inset map) indicates the data points used in the construction of the groundwater potential map. The map is more accurate where the data density GROUNDWATER POTENTIAL Data Density The potential of an area to supply water is dependant on the supply being of adequate quality and quantity. $ $ The quantity of water is represented by the colours from white to dark brown. The quality of water $$$$$$$$$ is represented by the green lines. $$$$$ For any comment or error, please contact $$$$$$$$$$$$$$$ $$ Water Resources Management Department $$$$$$$$ $$ $$$$$ Directorate of Water Development: 90000N $$$$$$$ $ $ 90000 N O T E $$$$$$$ $ a P.O. Box 19,Entebbe. $$$$$$$$$$$$$$ $ y $$$$$$$$$$$$ n Tel: (+256) 041 321342 $$$$$$$$$$$$$$$$ $ e $$$$$$$$$$$$$$$$$ $ K Fax : (+256) 041 321368 $$$$$$$$$$$$$$$$$ $ $$$$$$$$$$$$$$$$$$ f E-mail : [email protected] $$$$$$$$$$ To Ken ya o $$$$$$$$$$$$$$ PUBLISHER $$$$$$ $$ i c $$$ b l Compiled and published by the Water Resources u Management Department and the RUWASA project, ToTo ro r o p R e Scale 1 : 5,000,000 Uganda. Funded by the Government of Uganda 3036912151.5 Scaleキロメートル 1: 750,000 56,00028,000 0 56,000 キロメートル and DANIDA. Technical assistance by Wellfield Consulting Services Ltd (E-mail : [email protected]), a 620000E 630000E 640000E 650000E 660000E 670000E COPYRIGHT: Government of Uganda ,2002. THIS MAP MUST NOT BE CONSIDERED AN AUTHORITY ON DELIMITATION OF INTERNATIONAL AND OTHER BOUNDARIES First Edition , July 2002. Source: DWRM Figure 4-3 Example of Groundwater Potential Map on the Mapping Project (former Mbale district, it was divided to Mbale, Bududa, and Manafwa district) 4-2 The Development study on water resources development and management for Lake Kyoga Basin Final Report -Supporting- Chapter 4 Hydrogeology 4.1.3 Groundwater Monitoring 410000 510000 610000 710000 DWRM is monitoring the 400000 400000 groundwater levels by using the 4 010 20406080100 monitoring wells in Uganda. Although km 32 monitoring wells were constructed in whole Uganda. Now functioning 300000 300000 monitoring wells are only 11 locations, Loro CPAR because some boreholes have been >! already demolished, or some facilities Apac DWO >! are not functioning yet. Three wells of Soroti Otucopii 11 monitoring wells are in Lake 200000 >! 200000 Kyoga Basin; they are at Soroti, Pallisa, and Nkokonjeru. Figure 7-4 Pallisa >! shows the location of monitoring wells in and around Lake Kyoga 100000 100000 Basin. Figure 4-5 shows the Bombo relationship between groundwater >! Lake, Water body Nkokonjeru Lake Kyoga Basin level and rainfall, as an example of >! >! Monitoring_BH_Location 410000 510000 610000 710000 the monitoring data. According to Source: DWRM this data, it is recognized that water Figure 4-4 Location of Groundwater Monitoring Station level is rising after rainfall. The time lag can be estimated approximately 0.5 to 1 month. Soroti Otucopii Network Station Water Level and Rainfall Data 4 140 6 120 8 100 80 10 60 Depth to Water (m) to Water Depth 12 (mm) Rainfall Daily 40 14 20 16 0 98 98 99 99 00 00 01 01 01 02 02 03 03 03 04 04 05 05 05 06 06 07 07 08 7- - 5- - 3- 8- 1- 6- - 4- 9- 1- 6- - 4- 9- 2- 7- - 5- - 3- 8- 1- 12 10 11 Date 11 12 10 Source: DWRM Figure 4-5 Relationship between Groundwater Level and Rainfall 4-3 The Development study on water resources development and management for Lake Kyoga Basin Final Report -Supporting- Chapter 4 Hydrogeology 4.1.4 Borehole Completion Report Borehole Completion Report is submitted from drilling contractors 4 times a year. The data of NGWDB is based the reports. However, boreholes which were conducted the pumping test are not very much. The reports which were conducted pumping test properly were selected from whole reports. This purpose was to grasp the hydrogeological condition conducted by pumping test analysis ourselves, because these reports have no analysis result of pumping test. The number of report collected was 204, after exception of the data which the location was not clear and pumping test data was not good, the number of analyzable data was 158. Figure 4-6 shows the location of borehole which the pumping test data was analyzed. Most of the data are conducted constant rate pumping test and recovery test, however, step drawdown test data were very few. Most of pumping period of constant rate pumping test was 3 hours (180 minutes), few are 24 hours (1,440 minutes). However, there are some data which changed pumping rate in the period of constant rate test.