Nederland Fire has a split ISO classification:

In 2009/2010 NFPD lowered it's ISO rating, for the past 20 years we have had an ISO of 6 within Town limits due to hydranted water supply and an ISO of 9 in the rest of the District. There have been various folklore versions of this, but this is what the actual ratings were.

The "new' ratings are as follows:

Within Town Limits, due to fire hydrants the ISO CLASS is 5.

Outside of Town due to limited water supply the ISO CLASS is 8B.

ISO's Public Protection Classification (PPCTM) Program

To help establish appropriate fire insurance premiums for residential and commercial properties, insurance companies need reliable, up-to-date information about a community's fire-protection services. ISO provides that information through the Public Protection Classification (PPCTM) program.

What is the PPC program?
ISO collects information on municipal fire-protection efforts in communities throughout the United States. In each of those communities, ISO analyzes the relevant data using our Fire Suppression Rating Schedule (FSRS). We then assign a Public Protection Classification from 1 to 10. Class 1 generally represents superior property fire protection, and Class 10 indicates that the area's fire-suppression program doesn't meet ISO's minimum criteria.

By classifying communities' ability to suppress fires, ISO helps the communities evaluate their public fire-protection services. The program provides an objective, countrywide standard that helps fire departments in planning and budgeting for facilities, equipment, and training. And by securing lower fire insurance premiums for communities with better public protection, the PPC program provides incentives and rewards for communities that choose to improve their firefighting services.

http://www.isomitigation.com/ppc/0000/ppc0001.html for more information