Overuse of groundwater in coastal areas would most likely result in which of the following?

• A. Lower risk of flooding
• B. Increased agricultural productivity
• C. Saltwater intrusion into freshwater aquifers
• D. Improved water quality for local communities

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the context of groundwater use in coastal areas. Groundwater is stored in aquifers, which are underground layers of water-bearing permeable rock or materials.
2. Step 2: Recognize that overuse or excessive pumping of groundwater in coastal regions can lower the water table, reducing the pressure that keeps seawater from moving inland.
3. Step 3: Identify the consequence of this pressure reduction: seawater can intrude into freshwater aquifers, a process known as saltwater intrusion.
4. Step 4: Understand that saltwater intrusion contaminates the freshwater supply, making it unsuitable for drinking and irrigation, thus negatively affecting water quality.
5. Step 5: Conclude that the most likely result of overusing groundwater in coastal areas is saltwater intrusion into freshwater aquifers, rather than lower flooding risk, increased agricultural productivity, or improved water quality.