7.11A

A watershed is defined as a land area that collects and channels rainfall and snowmelt into creeks, streams, and rivers, making the first answer choice correct.

Lakes are a type of surface water, as they are bodies of water that collect on the Earth's surface. In contrast, aquifers, wells, and the water table refer to groundwater sources.

Runoff is a harmful effect of human activity on surface water as it carries pollutants from land into water bodies, degrading water quality. The other options, like minimizing usage and xeriscaping, are beneficial practices.

Fertilizer use can lead to nutrient runoff, which contaminates groundwater with nitrates and phosphates, causing pollution and harming aquatic ecosystems. This makes it a harmful influence on groundwater compared to the other options.