ASHLAND, Wis. (AP) - Northern Wisconsin's hundreds of lakes, large and small, are among the region's greatest treasures.

Ironically they are among the environments most threatened by rising development.  While the number of lakes remains constant, these limited resources are seeing increasing pressure of all kinds - from permanent vacation homes, to commercial development, to hunting, fishing and boating.

This is particularly true in Ashland County.

"Our workload has doubled between 1998 and 1999," said Ashland County Zoning Administrator Larry Hildebrandt.  "The current 'one size fits all' regulations that are applied regardless of the individual characteristics of lakes or streams don't make sense any more."

Hildebrandt said the county needed to have the ability to tailor regulations to fit the environment proposed for development.

One of the most important tools for fitting building and development plans to what the environment can safely handle is lakes classification, according Fred Gould of the Northwest Regional Planning Commission.  For the past three years, the commission has been assisting Ashland County in developing lakes classification criteria.

"One thing lakes classification does is to better protect smaller lakes which cannot take the kind of development that larger lakes can," he said.

Classification is a basic tool used by resource managers.  Applying these techniques to lakes and determining the level of development each lake can handle creates a playing field where all the participants know the rules and can adjust their proposed development plans accordingly.

In an ideal world, each lake would be classified individually based on the development it can handle given the lake's unique physical properties.

However, doing the kind of research work needed for such a scheme on Ashland County's 156 lakes would be an administrative and political nightmare.

Instead, using factors including hydrology, average depth, surface area, shoreland configuration, sensitivity to pollution and recreational use, a three-tier classification system has been developed.  This approach allows guidelines that reflect the lake's capacity to support development.  The idea is that some categories of lakes are more vulnerable to problems associated with overuse or are better suited to some uses than others.

The classification considers factors including lake surface area, maximum lake depth, whether the lake is a seepage, spring or drainage lake and the size of the lake's watershed.  A shoreland development factor measuring the degree of the lake's shoreland irregularity compared to its surface area is factored in.  When the appropriate factors are added together, the result determines if a given lake is a Class 1 lake, needing only minimum protection, a Class 2 lake needing moderate protection or a Class 3 lake needing the highest level of protection.

"We've been working on lakes classification, breaking the lakes down into categories since 1998," said Hildebrandt.

The task has included the county's 77 named lakes and 79 unnamed lakes.

Any lake under 20 acres is automatically listed as a Class 3 lake, however most of these lakes are located in county or national forests and therefore not subject to development, he said.

The zoning department has already received endorsement by the zoning committee to amend the shoreland zoning ordinance to include lakes classification.  A public hearing on the rule changes will take place in March and the changes will then be taken up by the full county board in late March or early April.

Hildebrandt said there is some time pressure associated with the time schedule.

"Because of the building season, we only have the winter to work with," he said.

Under the new rules, lakeshore buffer zones will increase from 35 feet to 50 feet.

"Present dwellings and existing lots will be grandfathered," Hildebrandt said. "Our goal is not to create any more non-conforming lots."

Another provision will be to require a 10-foot side lot setback minimum, and an aggregate of 40 foot of setback when both sides of the setback are totaled.

"We are trying to deal with some generic issues without being real controversial," he said.

Hildebrandt said the department would gather information about public feeling on the issue of "keyholing" a practice where backlot, off-lake property owners are given lake access through a narrow strip of lakeshore property.  The practice has been banned in several counties, including most recently, Bayfield County because it can cause greatly increased pressure on a small portion of the lake, leading to environmental degradation.

Two informational sessions are planned on January 28 on lakes classification and related issues, Hildebrandt said.  The first is at the Mellen Community Center from 10 a.m. to 11:30 a.m.  The second is at the Clam Lake Community Center from 1 p.m. to 2:30 p.m.  Both sessions are informal with any interested member of the public invited to attend, Hildebrandt said.

"Our lakes are dying a slow death.  We are trying to slow down that process," he said.  "Tailoring the protection we give the lakes to their need is a basic step."