Radio tower setbacks

[Linden Smith]

I've got a zoning ordinance requirement for a setback of 3500' for radio towers, not including cell phone towers. The setback cannot be met and a variance is needed along with a conditional use permit for the tower. Most other ordinances are under 1000' and some are based upon the height of the tower, one or two times the height.

I'm wondering if anyone has any innovative alternatives to language for siteing communications towers in rural areas.

 

[Repo Man]

I have seen ordinances that require 110% to 150% of the tower height from any street, sidewalk, or structure (except for the accessory buildings that serve the tower) as a setback requirement.

 

[Cardinal]

Most ordinances require a setback of some times the distance of the tower. They also usually fail to address the question of other structures on the lot. You may end up with a 300' tower, 600' from the lot line, and 50' from a building. The setback is based on the thought that the tower will fall over in one piece. That is not how it works. They are mostly designed to collapse in sections, coming down much like the way buildings are demolished. If I remember correctly, what we established was a setback of 1.5 times the tower hight, which could be reduced to a minimum of 150' upon the submission of evidence (engineering) that the structure was designed to fall in on itself and would not fall onto neighboring property.

 

[Jeff]

You really need to question the construction of the tower. If it is one of those simple triangular steel towers, they will fall over in one piece, but they usually aren't used at great heights. Everything else is designed to collapse on itself, as was said earlier.

However, the setbacks I have come across have always been some figure greater than 100% of the height, regardless of how it is designed to collapse.

Remember, there is a good possibility that there will be guy wires associated with a "less sturdy" (i.e the triangular kind) tower, so your setbacks will need to be able to accomodate that.

 

[Chet]

We use 105% of the FALL ZONE (not height). Most towers are designed for failure, and will break away at given points, As such, a 1,000 tower may have a 600 foot fall zone.

A structural engineer can certify a proposed tower's fall zone for you. (Just make sure you get it stamped!)

 

[Linden Smith]

Thanks for the imput. We have some paniky neighbors who want something unreasonable, and here we are dealing with a 3500' setback for a 400' tower. I'm thinking we may lose this one on appeal.

Another problem that came up was the BOA wanting to get involved with the EMF intensity. This is the domain of the FCC, but its all fair game for the opposition. Anyone ever had their local board wanting to go there?

Usually, I wouldn't care, but in this case this tower is the only way to get cell phone service and EMS repeaters for this part of the county.

 

[Cardinal]

Thanks for the imput. We have some paniky neighbors who want something unreasonable, and here we are dealing with a 3500' setback for a 400' tower. I'm thinking we may lose this one on appeal.

Another problem that came up was the BOA wanting to get involved with the EMF intensity. This is the domain of the FCC, but its all fair game for the opposition. Anyone ever had their local board wanting to go there?

Usually, I wouldn't care, but in this case this tower is the only way to get cell phone service and EMS repeaters for this part of the county.

You're right on the mark with the EMF issue. The Federal Telecommunications Act of 1996 specifically prohibits communities from considering EMF in zoning for towers. You wouldn't stand a chance of winning that one. I think the 3500' setback requirement would also likely be considered excessive if it were challenged. Communities are not permitted to make unreasonable demands or effectively zone-out towers. Our solution has them restricted to manufacturing zones or located on existing large structures such as water towers and tall buildings.

 

[solarstar]

I'll second that EMF is out of bounds, and related items such as bird/wildlife kills due to EMF's. We do have a provision that the applicant must provide an engineer's statement that the tower won't interfere with "usual and customary transmission or reception of radio and television". That has led to a few loudly complaining residents obtaining new TV's from tower companies, and otherwise helps ease concerns from residents.

I also agree that the setback requirement seems pretty excessive. Our setback to adjacent residential land is based on 125% of the tower height, although towers are limited to certain land use districts. We also only allow structures related to the tower operation within the certified fall zone (the applicant provides the certification, and most of the engineers play it safe with about 50% of the tower height). Good luck!

 

[Chet]

I'll second that EMF is out of bounds, and related items such as bird/wildlife kills due to EMF's.

When we were writing our wireless facilities ordinance, we came across this unbiased website.

 

[dczipf]

The setback is important not only to prevent injury and property damage from tower failure. Keep in mind these towers get covered with ice in freezing rain events. When the ice thaws and winds pick up pieces of ice will start flying through the air. Make sure that the engineer has designed the tower to withstand reasonable ice buildup.