The City Council voted last Thursday, November 5, to change the Austin Noise Ordinance once again.  This time they’ve added a distance limit for audibility from “sound equipment” on boats.

Section 9-2-3 (6):  A person may not operate sound equipment in a watercraft audible or causing vibration 100 feet from the equipment.

It takes effect November 16.

This is one more example of why our source-oriented ordinance is not tenable.  When the ordinance is source-oriented, you end up with a patchwork of restrictions that is stitched together over many years and terms of city council members.  The result is an inconsistent set of rules, each of which panders to whoever had a complaint at the time it was implemented.

The new watercraft noise rule is designed specifically to protect people who live on one of our lakes from hearing music from boats.  While this goal is not, in and of itself, a negative thing (people on lakes have just as much right to quiet as people not on lakes), it is hard to argue that it is equitable for a specific set of homeowners to get their own special protection.

Technically speaking, the new rule is all but impossible to satisfy.  There is no shielding and practically no ground absorption over water, so sound travels very efficiently.  In order to be inaudible, a sound needs to have levels somewhat below ambient levels.  In an area somewhat isolated from freeways and other typical city noise sources, you can expect ambient levels of around 35-40 dBA Leq.  In order to achieve 35 dBA from a distance of 100 feet, the noise source must be no louder than 61 dBA at a distance of 5 feet.

A typical conversation with someone a few feet from you is around 65 dBA Leq.  So in order to satisfy the new ordinance, someone on a boat may not turn up their stereo any louder than 4 dB below what a normal conversation would be (assuming they’re about 5 feet away from the stereo).  You can choose to talk to someone on your boat or you can choose to listen to music, but you cannot do both simultaneously.

And where do motors fall into this?  What boat motors are inaudible at 100 feet?

Even further, these simple estimates are based on generic A-weighted decibels.  In reality, music will have substantial low-frequency content that is not well represented in A-weighting but is still quite audible, especially against the backdrop of a quiet afternoon on the lake.

The arbitrary limit of 100 feet is also inequitable.  Boats that are 300 feet from any receiver are held to the same standards as boats that are near the shore.  I understand that the spirit of the law is not to punish people who are considerate enough to move further from the shore before turning up their stereos and that such people will probably never be ticketed.  However, there is no reason that the letter of the law should not truly capture the spirit of the law if it is possible.

It is time for us to rewrite our noise ordinance from scratch.  A fair, objective, uniform set of receiver-oriented standards should be established that applies to everyone equally.  The law should define illegal behavior based on its impact on other people.  A single rule defining a limit to how much noise one can subject a residence to will protect all residences equally, whether they are on Lake Austin or East of I-35.