| This is done before borehole drilling has commenced .The survey can be done by the following parties; |
_ licensed private hydro geologist
_ Water resource management authority.
The hydro geological survey report is based on the findings observed while
carrying out survey, it contains the following:
_ recommended depth
_ exact point of drilling
_ location map sheet, elevation and coordinates
_ hydro geological and geophysics of the area.
Geophysical survey and hydrogeological survey to determine groundwater potential/aquifer occurrence
1. Borehole Site Investigations –To investigate suitable sites for drilling boreholes or shallow wells in accordance with the Water Resources Management Authority (WRMA) – Kenya Requirements (for Kenyan based projects) or other requirements as per other country’s regulations.
2. Hydrogeological Surveys - For Borehole Site Investigations, groundwater availability studies and management, water resources management, aquifer mapping and modeling, well-field designs, groundwater monitoring, aquifer studies. Borehole condition assessment, groundwater recharge, groundwater quality assessment, determination of groundwater abstraction patterns and borehole density etc.
3. Geophysical Surveys – (for purposes of borehole drilling site surveying or geotechnical surveys). By use of ABEM Terrameter SAS 1000 series which can distinguish between clays and fresh water by use of Induced Polarization (IP) measurements. Methods employed are Horizontal Electrical proofing –HEP (Wenner Configuration) and Vertical electrical Soundings-VES (Schlumberger Configuration). Other methods of geophysical surveys also do exist but with varying degrees of applicability and viability. ling, determination of aquifer characteristics and types, aquifer size/location and depth, groundwater quality and hydrochemistry, abstraction patterns and aquifer depletion, groundwater recharge, saline water intrusion, aquifer contamination etc.
4. Aquifer Studies – Includes aquifer modeling, determination of aquifer characteristics and types, aquifer size/location and depth, groundwater quality and hydrochemistry, abstraction patterns and aquifer depletion, groundwater recharge, saline water intrusion, aquifer contamination etc.
5. Groundwater modeling
6. Water Resources Assessment
7. Borehole Condition Assessment - Done on problematic existing boreholes to investigate the course of such problems and the way forward to solve the problems or recommend alternatives to supplement the water supply etc.
8. Groundwater Monitoring.