They dip and climb, rise sharply, and jut toward the sky. Sometimes the slope levels to green fields outlined with rugged trees. On others, the edges are sandstone rocks weathered into steep angles that fall to green hillsides below.
Every bluff has unique dimensions. In the Winona region, government entities attempting to protect the view of area bluffs from below have had to start by first defining where a bluff top begins. Both the city of Winona and Winona County have used slope calculations and setbacks to define the tops of bluffs to ensure that new buildings are not constructed so close to the edge as to be seen from the valley below.
In March 2010, the Winona County Board voted that county planners should study a new kind of geospatial technology as a means to protect the bluff tops from development, a charge outlined in the zoning ordinance. Thirty-one months later, the job has still not begun.
During the time the zoning ordinance was being rewritten, from 2007 to 2012, Winona County leaders studied the various ways bluffs could be protected. County board members learned about a tool called “viewshed analysis.” It is a Geographic Information System (GIS) program that allows technicians to create maps showing the location on a ridge where a structure could be seen from below.
County leaders and county planners, however, disagreed about how the viewshed tool should be used. Former County Planning Director Brian Bender argued that without defining exactly what the county was trying to protect—from what vantage point views should be free of structures on the ridge lines—the tool would be too subjective. County board members discussed using highly-traveled valley roadways as a basis for places where views of the bluffs should be protected. They eventually asked that the viewshed analysis language be left out of the bluff protection ordinance until the Winona County Planning Commission could study the issue more thoroughly. In March 2010, the board passed a resolution which stated that although viewshed analysis language should be left out of the draft, it should be studied and brought back to the board within three months of the date on which the entire zoning ordinance was approved.
The next time the board met on the ordinance, Bender had returned the viewshed analysis language to the draft ordinance. When questioned about its inclusion, since the board had voted to remove the language, Bender said he had placed the generic language into the ordinance to serve as a place holder to remind planning staff that there was work yet to be done.
It has been 31 months since county commissioners asked that planning staff and the planning commission address how viewshed analysis systems could be used as a more accurate way to evaluate development proposals near the tops of bluffs. Current County Planning and Environmental Services Director Jason Gilman, who took the post after the work was completed to rewrite the bluff protection portion of the ordinance, said he was unaware of the board’s directive.
The work ahead
While the viewshed analysis tool is included in the zoning ordinance today, it is not an “absolute” tool, meaning that its findings are just one consideration county leaders use when determining whether to issue a permit to build. The ordinance states, “Viewshed analysis shall be employed as an evaluation tool to be considered as part of the decision making process,” for structures that require a conditional use permit (CUP) to build near a bluff top.
When the board discussed its use back in 2010, Bender expressed concern about using the tool in this way. He recommended that the tool, unless specific areas where views are protected are determined, shouldn’t be used at all. He said if those specifics were not identified, it couldn’t be used without becoming overly restrictive or inconsistent. “I’m not disputing the value of [viewshed analysis],” he said. “We just can’t make it work in a consistent way. We spent weeks trying to work on it.”
The city of Winona was able to find a way to define specific areas where views should be protected using the viewshed analysis technology. Called the “Mississippi River Viewshed Corridor,” the area with protected views is identified in the city’s ordinance as all land of the city located between the southerly right-of-way line of Highway 61 to the southerly shoreline of the Main Channel of the Mississippi River. If a proposed structure is possibly able to be seen from that defined area using a viewshed analysis, city staff may impose additional conditions, such as planting vegetation, to try to prevent that visibility.
Gilman was not optimistic about the chances of the county finding specific parameters for the viewshed analysis tool to be employed as a more absolute measurement. “I think in order to actually use it as an absolute tool, you have to first define what you don’t want to allow in greater detail,” he said, “but that’s a higher-level policy decision that the elected body has to make.”
Although it may prove challenging, Gilman said, “I think what I will propose to do is bring this up with staff and our planning commission and see whether they would like to pursue any further study of the use of that tool.”