I am a Congolese hydrogeologist. Groundwater resources of the DRC are unknown. I am making a database of existing Wells and borehole with hydrogeology data.
I can't help specifically on DRC recharge data, but two places to look (and to add) information on DRC's hydrogeology is the Africa Groundwater Atlas and Grey Literature Archive:
It will be difficult for an outsider to have the data that you are looking for. What you need to do is to visit in person or write to the various offices in charge of water projects in Congo and request for the reports submitted to them.
Again, you can also query Google to see publications, reports and so on, from the area.
I guest this question should not be directed to researchers that are far from Congo. Questioners can narrow it to researcher in Congo and adjourning areas in order to get meaningful response. Besides, if the data are classified, there may be difficulty in releasing the data by any unauthorized person(s). Therefore, the agencies in charge of groundwater in Congo should be contacted rather than ordinary researchers in Congo
You may consider reviewing both grey and published scientific literature, for example via 'ScienceDirect, Scopus (https://www.elsevier.com/en-au/solutions/scopus)...etc.
Thank you all for your replies. I should mention that I am one of the authors of the Hydrogeology of the Democratic Republic of Congo published in the Africa Groundwater Atlas (http://earthwise.bgs.ac.uk/index.php/Hydrogeology_of_Democratic_Republic_of_the_Congo). Which is being updated.
It is very difficult to get data related to groundwater in DRC for two reasons:
1) No much interest was given to groundwater though it is the mostly used for water supply in rural and peri urban areas.
2) No à dedicated governmental department like in the Botswana, South Africa, USA, etc...
3) Congolese hydrogeologists working inside the country are rare (less than 10 in such a continental country) . International researchers/consultants have done most of works related to groundwater in the DRC and should be the right source of data.
I have gathered some data on groundwater... I need to populate the database. Some reports are referred to in old publications but very difficult to find. Some people keep data/reports in their computer while others are struggling to have access to it. This is very common in many countries where there is no databases at national or provincial level.
Researchgate should be the right place where people can meet and share data or knowledge.