Here's a precipitation-collection tank, or cistern, that's patially burried and hidden by a raised planter bed and a combination of beautiful and edible plants. The easiest way to see where the cistern is in this photo is to look for a brown downspout that elbows from the right post of the portal. That goes into a 650 gallon cistern from which water is pumped and distributed through the backyard with a hose. I took this shot at our a client's residence around this time of year several years ago. One of the reasons to go this route when installing a cistern is to save money on exacavation, but don't forget to figure in the cost of the wood and labor involved in the screening with the landscape timbers that make up the raised bed. You will also be limited to plants that sprawl and cover ground even with root systems that get shrunk by the tank which is only 4" to 12" below the ground.