Everyone is a critic and an expert. I think you have a wonderfully engineered solution. The goal of the project was to simply and cheaply apply water to the grassy portion of your yard and you are 100% successful. That is an engineered solution. If you want to develop an expensive, time consuming, overly designed, full of regulated nonsense solution, you could have done that. That is a government solution. The only replies you have to over-engineer the system are from people who are neither an engineer or have a monetary interest in your failure. This is putting water on a lawn people! Does not require a doctoral thesis. I appreciate the knowledge you shared here an plan to install a similar system when I get the time.