Pacific Palisades Grading Plan: 12% Slope, Basement Level, and Deep Trench Drainage

If you are building on a steep lot in Pacific Palisades, you already know the challenges. Steep streets, tight property lines, and basement requirements add layers of complexity that a flat lot simply does not have. This one had all of that plus a twist: the existing house still shows on Google Street View, which meant we had to work with what was there while designing something new.

We recently wrapped up a grading plan for a Pacific Palisades fire rebuild on a 12% slope. Here is how we handled it.

The Site Challenge

The street itself is steep at about 12%. The proposed driveway apron had to connect to the basement and garage finished floor, which the architect called out on the plans. The garage and basement sit on the same level, with a lightwell behind the basement.

The first story of the new house sits roughly where the existing house was, tying into the existing grade pretty closely. But the basement level required excavation deeper into the hillside, which is where things got interesting.

Drainage Approach

We used area drains throughout the site to collect stormwater. A deep trench was cut to pipe everything out to the street. The drainage connection uses a circle to rectangle adapter, finishing with a rectangular steel pipe that outlets through the curbface.

This setup handles the stormwater from the garage level and the lightwell, routing it safely down to the street without letting water sit against the foundation.

Excavation and Shoring

The excavation plan shows a 4-foot max vertical cut with 1:1 trim to daylight. Where we could daylight within the property line, we did. But anywhere too close to the property line required shoring instead.

That is typical for Pacific Palisades hillside construction. When you cannot slope back because of property boundaries, shoring keeps the excavation stable while you build the foundation and retaining walls.

Services Provided

This Pacific Palisades project required:

• Grading plans — proposed grades, drainage routing, and driveway apron connection
• Excavation plans — 4-foot max vertical cut, 1:1 trim to daylight, shoring limits where property lines prevent daylighting
• Drainage plans — area drains, deep trench, circle-to-rectangle adapter, rectangular steel pipe outlet through curbface

For Pacific Palisades hillside projects, we can look at your specific site and tell you what the planning department will require before you submit.

No obligation. Just useful information if you are early in the process and trying to figure out what you actually need.