Grading and drainage in Scottsdale

In Scottsdale, stormwater is planned on paper before it's shaped on the ground. The city's Grading & Drainage Checklist lists what an engineered grading and drainage plan has to show.

From the city's checklist

• Volumes on the plan: the drainage basin volume required and the volume provided.
• Shallow basins: a 3-foot maximum water depth, with side slopes no steeper than 4:1.
• The 100-year storm: a 100-year water surface elevation calculation, and on streets, 100-year runoff staying in the right-of-way at no more than 8 inches above the gutter flowline.
• Flood information: a FEMA information block, with the design complying with the city's floodplain and stormwater regulations.
• Engineer sign-off: as-built drawings and the final drainage basin certification, with capacity calculations, from an engineer registered in Arizona.
• Dust: the checklist's permit list includes obtaining a Maricopa County dust control permit.

The checklist was last revised in 2005 and works alongside the city's Design Standards and Policies Manual and any project-specific conditions. Your project coordinator at the city has the final word on what your plan needs.

Washes

In the ESL overlay, the goal is to leave washes in place and in natural condition where practical. The city's ESL guide treats a watercourse carrying 750 cubic feet per second or more in a 100-year storm as major, and 50 to 750 cfs as minor, and doesn't allow building within the 100-year floodplain of either. Walls aren't supposed to cross watercourses.

Cost

Angi's Phoenix-area guide lists yard grading and leveling at $415 to $6,720, leveling at $5 to $15 per cubic yard, and an operated machine at $105 to $260 an hour. Engineering and the grading permit are separate costs.

Dust

Maricopa County requires a dust control permit for disturbing 0.10 acre (4,356 square feet) or more, and every dust-generating operation must follow Rule 310 whatever its size.