This is the rule that catches people. The Village requires lots to retain localized stormwater on site unless the Village Engineer approves otherwise, and sizes the pond with a set formula: total impervious area on the lot × 2.99 ÷ 12 = cubic feet of required pond volume. Runoff from driveways may not be diverted onto a public street or into an adjacent bar ditch; it has to be held in on-site ponds that the owner maintains.
As an example of the math: a new 1,200-square-foot driveway adds 1,200 × 2.99 ÷ 12 ≈ 299 cubic feet of pond volume to the lot's total. We grade driveways and patios to send water toward the pond, not toward the road or the acequia.
If the building site is west of the Corrales Main Canal, the Village requires a grading and drainage plan sealed by a New Mexico professional engineer or architect. If the property is in a flood zone, an elevation certificate from a licensed surveyor is part of the permit package.