The enabling legislation of the St. Croix National Scenic Riverway, the Wild and Scenic Rivers Act of 1968, directs the National Park Service (NPS) to collect information and take actions to help preserve the scenic beauty for which the St. Croix River was designated. Preserving the scenic beauty ranges from controlling residential building via scenic easements to providing technical assistance to communities bordering the river that wish to reduce their visual impact on river users and others. The latter case is one with which the NPS was recently involved, and concerned a small community on the Minnesota side of the river (the St. Croix River serves as the boundary between Minnesota & Wisconsin for much of its length).
The community was interested in looking at development and adoption of a bluff development ordinance to 1) protect scenic vistas from the river, and 2) help city administrators determine what slope range could be considered suitable for development. The NPS was primarily interested in item 1-helping the city preserve the "viewshed" presently afforded those viewing the Minnesota shore.
The process used to create the variable slope map was to digitize the contours from the applicable USGS 7.5' quadrangle, create a Digital Elevation Model (DEM) in Arc/Info, and derive the two slope categories (between ~12% & ~18%, and greater than ~18%) from that product. The slope values are based on those used by the Lower St. Croix Management Commission to designate where individuals may build within the Riverway boundary.
Products provided by the park (maps, aerial photos, and results of additional research) were given to the city in May of 2000, and the city continues to deliberate the pros (protection of scenic beauty, establish positive precedent for similar municipalities) and cons (infringement on personal property rights, restriction of growth opportunities) of establishing a bluff development ordinance. Additionally, a major desire of the city is to be able to transfer the results of the slope analysis to specific locations out in the field, and they continue to seek a means to accomplish this, with assistance from the park. In the interim, they have passed a vegetation/tree protection ordinance.
GPS/CELL PHONE MAP TEXT ITEM
A telecommunications company wished to situate a 180'-250'-high cellular telephone tower on private land directly adjacent to the Lower St. Croix National Scenic Riverway. Due to the potential for degradation of the scenic value of the Lower St. Croix NSR, the NPS sprang into action, requesting from the company a crane test to match the proposed tower height(s) and organizing teams of park staff and volunteers to station themselves at various points along the river to collect data. Prior to the crane test, a GIS-based viewshed analysis was done to ascertain from which parts of the river and surrounding areas the tower might be seen. Based on that analysis, the teams were located in boats upstream and downstream of the crane test points, and along several highways/roads in both Minnesota and Wisconsin. Radio contact was maintained between all of the parties, and GPS data were collected to record points/lines from which the three separate crane tests were visible.
Five months later, the aforementioned cellular tower has not been erected, one additional tower installation has been postponed, and the five counties bordering the Lower St. Croix NSR have formed a regional planning group that is engaged in developing a coordinated strategy to address telecommunication tower placement efforts. Those efforts include establishing model telecommunication ordinances that address siting issues in a manner consistent with protecting the valley's viewshed and reviewing regulations that make it difficult for telecommunication companies to consider alternatives. The group is also exploring the use of new "stealth tower" and antennae technology to provide adequate service in a way that preserves the valley's scenic resources.
