Yes, a science fair project about conserving water with shower heads would definitely fall under the category of environmental science.

Here's why:

* Focus on the Environment: The project directly addresses the impact of water usage on the environment. Water conservation is a crucial aspect of protecting natural resources and minimizing our ecological footprint.

* Resource Management: By exploring different shower heads and their water efficiency, the project delves into resource management, a key area of environmental science.

* Sustainable Solutions: The project promotes the use of sustainable practices and technologies, which is a core principle of environmental science.

While the project also involves aspects of physics (water pressure, flow rate) and possibly even engineering (designing shower head modifications), the overarching theme and goal clearly align with the field of environmental science.