The river basin which makes the maximum utilization of groundwater is the Brahmaputra river basin. The Brahmaputra river is one of the major rivers in Asia, flowing through China, India, and Bangladesh. It is known for its vast basin area and high water discharge.

Here is a detailed explanation of why the Brahmaputra river basin makes the maximum utilization of groundwater:

1. Geographical Factors:
- The Brahmaputra river basin covers a large area in Northeast India, including parts of Assam, Arunachal Pradesh, and Meghalaya. These regions have favorable geological conditions for groundwater storage and recharge.
- The basin is surrounded by the Eastern Himalayas, which receive significant rainfall. This abundant rainfall contributes to the recharge of groundwater reservoirs.

2. Alluvial Soil:
- The Brahmaputra river carries a huge amount of sediment from the Himalayas, depositing it in the basin. This sediment consists of alluvial soil, which is highly permeable and ideal for groundwater storage.
- Alluvial soil has high porosity, allowing water to percolate easily and replenish the underground aquifers.

3. Groundwater Extraction:
- The agricultural activities in the Brahmaputra river basin heavily rely on groundwater irrigation. Farmers extract groundwater through wells and tube wells to meet their water requirements for irrigation.
- The fertile alluvial soil and availability of groundwater make the basin suitable for extensive agriculture, leading to high groundwater utilization.

4. River Water Availability:
- The Brahmaputra river has a substantial water discharge, especially during the monsoon season. This abundant river water supply allows for significant recharge of groundwater reservoirs.
- The river water also helps maintain a favorable water table, ensuring the availability of groundwater throughout the year.

5. Economic Importance:
- The Brahmaputra river basin is economically significant, supporting various industries and hydropower projects. The availability of groundwater plays a crucial role in sustaining these economic activities.

In conclusion, the Brahmaputra river basin makes the maximum utilization of groundwater due to its favorable geographical factors, alluvial soil, extensive agriculture, abundant river water availability, and economic importance. The combination of these factors makes it a prime region for groundwater utilization in comparison to other river basins like Ganga, Satluj, and Indus.