While our land division application was with the city we began to get feedback from our city planner. The first hurdle had to do with storm water systems. The gutters on our existing home feed to pipes in the ground that we did not know where they ran to. To discover this I hired Environmental Works to come out and scope the rain drains.
It was found that the drains went to an underground *drywell. This is a great stormwater mitigation, but unfortunately the drywell is located in the backyard mostly on the new lot. The city let us know that we would be required to decommission the drywell and redirect our storm water on the existing house. To do this we pulled the rain drains out of the pipes to the drywell and directed them to splashguards. Easy peasy.
*A drywell is an underground structure that disposes of unwanted water, most commonly surface runoff and stormwater, and in some cases greywater. It is a covered, porous-walled chamber that allows water to slowly soak into the ground, dissipating into the groundwater.