In Texas, whether you need a permit for a 5,000 gallon water storage tank can depend on its intended use. If the tank is part of a fire protection plan, such as for fire preparedness, you may be required to obtain a permit to ensure compliance with local regulations. Generally, water storage tanks for agricultural or domestic use might have different requirements. It’s essential to check with your local authorities to understand the specific regulations that apply to your situation, especially when it comes to fire protection measures.