My house was built in the 1960s and is one of the oldest houses in the neighborhood. Most of the other houses were built in the 1990s, and I suspect that drainage patterns, and even the road elevation, has changed quite a bit since my house was built. The road is slightly elevated relative the yard immediately adjacent to it, so the yard gets water off the road during heavy rains.

The house currently has two downspouts and a sump pump. The sump pump empties into the yard about 10 feet from the house. The downspouts have short pipes on the end the direct the rain a few feet away from the house. Later this summer I'm hoping to install a drainage system that would collect water from the downspouts and sump pump. The endpoint of the drainage system will be the rain garden. I also plan to correct the grade around the foundation of the house to keep water away from the foundation. The picture below shows the general location of the rain garden. I'd like to install it in the area between the hammock and the veggie garden.

With the extra water from the sump pump and road, I'm planning for a rain garden that is larger than 20% of the roof area. The soil in this area is sandy and well drained. I'm excited to do the infiltration test to see how it behaves. My plan is to eventually replace most the lawn with native plants, so this rain garden will be a good jump start!