Zoning wall height - what is average ground level?

[danSAA]

Question regarding LA County Municipal Code:

22.110.070 Fences and Walls.

A. Measuring Height of Fences and Walls. The height of a fence or wall shall be measured at the highest average ground level within three feet of either side of said wall or fence. In order to allow for variation in topography, the height of a required fence or wall may vary an amount not to exceed six inches; provided that the average height of such fence or wall shall not exceed the specified maximum height...

What does "highest average ground level within three feet of either side" mean? Is that average of the higher side or both sides? Sketch of proposed 6 foot high CMU wall at property line:

The code continues with an example, which is meaningless to the above text because the image just explains how wall heights are lower in front yard setback.

... For example, see Figure 22.110.070-A, below.

FIGURE 22.110.070-A: MEASURING FENCE HEIGHT

Legend:
_____________________
A = Required front yard
B = Fence height within the required front yard
C = Fence height after the required front yard

Bonus question - if a home owner wants to add CMU walls around the rear and sides of their yard, but the natural drainage course of the surrounding properties drains across their property (side to side at about 7% slope), is that allowed? I'm thinking we could call for through-wall holes every 8 feet or so. But I worry that in the long term those holes will get buried and/or clogged and cause ponding on the uphill side.

 

[jar546]

Our zoning code needs to be amended because it is measured to the ground on both sides, and the taller side limits it. This is causing a lot of problems because many new homes have to bring in fill and raise the grade because they are in a flood zone where the FIRMs has recently changed. This causes a problem for the neighbors, and the new homes end up having to install a retaining wall, then want a fence in their yard, hence the obvious issue. I would like to see a productive discussion on this topic.

 

[Yikes]

You can always check with LA County planners. My opinion is that option #2 shows the average ground level within either side of the fence, not the "highest average". Therefore Option #2 is incorrect.
The only way the phrase "highest average... of either side" makes sense is that you first calculate two different averages, one for each side of the fence, then you take the highest one of those.

In the example below:

Left side average = (A+B)/2​

Right side average = (C+D)/2​

Whichever of the 2 results is higher, (in the illustration below, it's the right side), you use that result, and discard the low side (left side) average result. Then using the high/right side only, add 6 feet and that's the maximum allowable fence height.
Top of fence = ((C+D)/2) + 6 '


So, I believe your Option #1 is closer to the intent of the zoning code. But to be precise, the intent is not to eyeball one side that looks like it might be highest, then only do the average of that side. It is to first do TWO different average calcs to mathematically demonstrate which side contains the highest average, THEN throw out the low side result and only use the high side average for fence height determination.

Note that since the wording is "side of the fence", IMO you measure the 3' from the face of the fence, not the centerline of the fence. Others may disagree with this, and the plan checker probably won't look that closely anyway.

My guess is that the reason they said "highest average... of either side" was that they got tired of residents asking: "do I measure from my side or my neighbor's side?"

 

[danSAA]

@Yikes - I like your answer. Getting questions answered from the County, or AHJ is always a crapshoot, either radio silence or someone very helpful. I'll give it a shot and/or put a diagram in my drawing set to hopefully get approval.

 

[Yikes]

@danSAA - Another example where the phrase "highest average... of either side" is helpful is if the length of fence/wall straddles diagonally across the ridgeline of a hill, the side that is considered higher may actually switch from left to right as it crosses the ridge.