Could drinking water help lower your blood pressure?

Blood pressure: It isn't a blood pressure lowering agent. If you're anxious about being thirsty maybe on that occassion but not as a rule.

Hydration is good: Sure. Being adequately hydrated is really important for good health. If by drinking water, you are drinking less of calorie laden drinks that will make you overweight and more prone to hypertension, then yes that will help. I don't think there's a direct correlation between water and lowering bp, but certainly an overall healthier option.