The performance of a well is measured by its specific capacity.

Specific capacity refers to the rate at which a well can produce water under specific conditions. It is an important parameter used to assess the efficiency and productivity of a well. Several factors contribute to the specific capacity of a well, including its design, construction, and the characteristics of the aquifer it is tapping into.

Factors Affecting Specific Capacity:
1. Well Design: The design of a well plays a crucial role in determining its specific capacity. Factors such as well diameter, screen length, and well depth can affect the amount of water that can be extracted from the aquifer.

2. Aquifer Characteristics: The properties of the aquifer, such as its permeability and storativity, also influence the specific capacity of a well. A highly permeable aquifer with good storage properties will generally yield a higher specific capacity.

3. Pumping Rate: The rate at which water is pumped from the well can impact its specific capacity. If the pumping rate exceeds the aquifer's ability to recharge, the specific capacity may decrease over time.

Importance of Specific Capacity:
1. Efficiency Evaluation: Specific capacity provides a measure of a well's efficiency in terms of water production. It helps determine whether a well is capable of meeting the water demand of a particular area.

2. Resource Management: By assessing the specific capacity of wells in an aquifer, resource managers can better understand the available water supply and make informed decisions regarding water allocation and usage.

3. Well Maintenance: Monitoring the specific capacity of a well over time can help identify any changes or declines in its performance. This information is crucial for proper well maintenance and addressing any issues that may affect its productivity.

4. Planning and Development: Specific capacity data is essential for planning and developing new wells. It allows for the identification of suitable locations and design specifications that can maximize water production.

In conclusion, specific capacity is a key parameter used to measure the performance of a well. It considers factors such as well design, aquifer characteristics, and pumping rate to assess the efficiency and productivity of a well in terms of water production. Monitoring specific capacity is essential for resource management, well maintenance, and planning future water supply projects.