Wisconsin Coastal GIS Applications Project

Shoreland Management GIS Application
Blue Lake, Oneida County

David Hart and Todd Sutphin
University of Wisconsin Sea Grant Institute and
Land Information and Computer Graphics Facility, University of Wisconsin-Madison


Contents

Overview of the Shoreland Management GIS Application
Background
Thematic Mapping of Property Attributes
Shoreland Zoning Jurisdiction and Waterline Setbacks
Septic System Maintenance Notification
Site Selection for a County Park
Digital Orthophotos and Digital Raster Graphs
Hot Links to Photographs of Shoreside Structures
Acknowledgments

Download the Blue Lake Shoreland Management GIS Training Exercise (Adobe Acrobat document - file size: 124K). The instructions are in Adobe Acrobat .pdf format. If you don't have Acrobat Reader, you can download it from the Adobe website. This free software will allow you to read and print the instructions.

Download Shoreland Management GIS Training Data Sets (zipped-file size: 5.7 MB). The data sets are archived in .zip format. An evaluation version of the shareware software to extract the data can be obtained from WinZip website.


Overview of the Shoreland Management GIS Application

All land in Wisconsin within 1000 feet of the ordinary high water mark (OHWM) of navigable lakes, ponds, or flowages or 300 feet from the OHWM of a navigable river or stream (or to the landward side of the floodplain if that is greater) is subject to shoreland zoning. GIS has been utilized to improve the administration and enforcement of zoning ordinances. This section reviews the development of a GIS application for shoreland zoning and associated lake management concerns on an inland lake in northern Wisconsin. The site of the application is Blue Lake in northwest Oneida County near Minocqua, Wisconsin. The application was developed using ArcView 3 software produced by Environmental Systems Research Institute (Redlands, California). Software functionality utilized in the application includes data import and integration, linkage to a relational database management system, thematic mapping, spatial analysis and query, image interpretation, and inter-application connectivity.


Background

Oneida County is part of the northern temperate lakes district of Wisconsin and Michigan, a region characterized by one of the highest concentration of inland lakes in the world. Oneida County contains 426 named and 701 unnamed lakes. The total surface area of the county is 779,235 acres. Of this, 74,415 acres (10.5 percent) is water. Important research in the early development of the field of limnology was conducted in the region and the area is known as the "cradle of limnology."

Development Pressures. Development in Oneida County has increased over the past several decades. There has been a boom in construction of both seasonal recreational homes and permanent residences. The number of new building permits has increased from 1,112 in 1989 to 1,643 in 1993. A total of 825 new sanitary permits were issued in 1993, up from 557 in 1989. Much of the new construction activity has taken place on lakefront property. Of the single family homes constructed in 1993, 52 percent were on lakefront properties. The 1990 census indicates that 11,263 of 25,173 total housing units in the county (45 percent) are seasonal. Developable lakefront property is becoming scarce and, as a result, shoreside property values have risen dramatically.

Commercial development is also active in Oneida County. The county is a major tourism destination, with over 300 lodging facilities offering approximately 3200 rooms; 37 campgrounds with over 1500 total campsites; and seventeen recreation camps serving approximately 2,800 people. Lodging occupancy information and visitor surveys indicate that Oneida County serves an average summer seasonal population of over 55,000 people, which is almost double the 1990 permanent population of 31,679.

The History of Rural Zoning in Oneida County. In May 1933, Oneida County enacted the first comprehensive rural zoning ordinance in the United States. In the early 1930's, most northern Wisconsin counties were facing financial difficulties stemming, in part, from difficulties in converting cut-over forest lands to agriculture. The purpose of the rural zoning ordinance was to restrict settlement in remote areas. The Oneida County Board of Supervisors was concerned about the high costs of transporting school children and the construction and maintenance of roads in remote areas. The ordinance eventually became a model for other counties in Wisconsin and promoted the creation of county forest preserves across northern Wisconsin.

Since that time, the nature of zoning in rural Oneida County has changed. The County adopted a Shorelands Protection Ordinance in November 1970 based on state enabling legislation. The ordinance has since been revised several times. It is now identified as the Oneida County Zoning and Shorelands Protection Ordinance. Amendments to the ordinance include provisions on mining, signage, non-conforming structures, and placement of mobile and manufactured homes.

Protecting Water Quality and Aesthetics. Given the increasing development pressure in the county and the fact that much of the new development is located on the county's fragile lake ecosystems, regulation of shoreland development is very important. Failing septic systems, construction site soil erosion, runoff of lawn fertilizers, and other sources represent non-point sources of pollution that impair water quality. Water quality impairment threatens fish and wildlife habitat and aesthetics. Various structural violations of the shoreland ordinance requirements may also threaten the water quality and natural beauty of the lake resources.

To address these concerns, Oneida County has initiated a comprehensive revision of the zoning and shoreland protection ordinance. The overall goals of the project are to improve compliance rates of new and existing shoreland development, and to protect shoreland and lake ecosystem quality. Funding for the multi-year effort comes from local sources and a state lakes protection grant. The scope of the project includes: (1) an assessment of shoreland zoning compliance and resource problems; (2) revision of mining provisions in shorelands and floodplains; (3) comprehensive revision of the zoning and shoreland protection ordinance to improve its administration; (4) community education on the revised regulations; and (5) creation of a program to monitor and enforce the revised ordinance.

Spatial Information Technologies for Enforcement of Shoreland Zoning. Oneida County has an active land records modernization program and is exploring methods to incorporate GIS/LIS technology to assist in administration and enforcement of the zoning and shoreland protection ordinance. Specific activities include creation of digital parcel maps, development of parcel identification numbers (PINs) to link property attributes to the parcel map, development of digital orthophotos on a regular time frame, and incorporation of aerial or boat based videography to help detect property changes and zoning violations.


Thematic Mapping of Parcel Attributes

The first set of images examine thematic mapping of attributes from property assessment and ownership files. Despite the relatively straight-forward nature of the software tools used to join these databases with parcel maps using unique parcel identifiers, the resulting maps represent products that were difficult and time-consuming to generate before the advent of automated mapping and GIS. The first two images examine assessed value of the land (Figure 2) and assessed value of the land per square foot (Figure 3) of lakefront properties. One can see that there is a wide variation of assessed values surrounding the lake, with lakefront properties containing improvements showing the highest assessed values of land per square foot. Figure 4 shows classes of property ownership based on the zip code of where the tax bill is sent.

Figure 2: Assessed Value of the Land

Figure 3: Assessed Value of the Land per Square Foot

Figure 4: Property Ownership: Wisconsin vs. Out-of-State


Shoreland Zoning Jurisdiction and Waterline Setbacks

The second set of images examine tools to aid the administration of the shoreland zoning ordinance. The lighter green area in Figure 5 represents the area of the jurisdiction of the shoreland zoning ordinance within 100 feet of Blue Lake, while the darker green area is the area impacted by the 75 foot setback requirement. Figure 6 shows the results of two theme on theme selections. The first identifies all structures within the 75 foot setback (in yellow) and the second shows the parcels that intersect with the selected set of buildings (in purple hatching). Figure 7 shows a section of a hypertext-linked help file of the Oneida County Shoreland Zoning Ordinance. The help file was created using RoboHelp software from Blue Sky Software (LaJolla, CA). Linking the zoning ordinance text and maps within the same environment have the potential the make the administration of shoreland zoning more effective, particularly when working directly with permit applicants.

Figure 5: Shoreland Zoning Jurisdiction and Shoreland Setbacks-Entire Lake

Figure 6: Shoreland Setbacks-Blue Lake Island

Figure 7: Shoreland Zoning Ordinance in Hypertext Help File


Septic System Maintenance Notification

State regulations in Wisconsin require that septic tanks be pumped every three years. Oneida County is a rural county with over 1100 lakes. Notifying property owners of septic pumping requirements using manual methods has been a burdensome responsibility for county officials. These images show how a septic tank notification application might be designed using GIS. The tank locations and associated attribute data are fictitious, but illustrate the principles. A spatial query selects all septic tanks last pumped in 1994 or before. A theme on theme selection intersects the selected set of septic tanks with the parcel theme and allows access to property ownership information. The mail merge capabilities of a word processing software package can then be used to prepare form letters and labels to automate the notification process.

Figure 8: Fictitious Septic Tank Locations with Query

Figure 9: Form Letter for Septic Tank Maintenance Notification


Site Selection for a County Park

The following collection of images illustrates a hypothetical site selection process for a lakefront county park. A series of theme on theme selections and spatial queries are used to identify an "optimal" location for the park. The first query identifies all developed parcels and then reverses the selection set to start with all undeveloped parcels (Figure 10). The next criterion is that the site must have lake frontage (Figure 11). After that, sites that border developed parcels are eliminated so that the future park site is "remote" and will minimize nuisances to neighbors (Figure 12). Next, a minimum size restriction of two acres is imposed (Figure 13). Finally, any remaining sites that include wetlands are eliminated (Figure 14), leaving the "prefered" site. A benefit of this approach is that, if the County Board wished to modify the selection process, the criteria could be changed with relative ease.

Figure 10: Lakeside Park Site Selection (Step 1)-Vacant and Developed Parcels

Figure 11: Lakeside Park Site Selection (Step 2)-Lakeside Parcels

Figure 12: Lakeside Park Site Selection (Step 3)-"Remote" Parcels

Figure 13: Lakeside Park Site Selection (Step 4)-Parcels Greater Than 2 Acres

Figure 14: Lakeside Park Site Selection (Step 5)-Non Wetland Parcels/Preferred Site


Digital Orthophotos and Digital Raster Graphs

Digital orthophotos used in conjunction with Digital Raster Graphs (DRGs) represent a means of integrating image data into the shoreland zoning/lake management application (Figure 15). DRGs are scanned, geo-rectified U.S.G.S. 7.5' topographic maps. The image legend editor in ArcView allows the individual colors of the DRG to be changed or made transparent. Figure 16 shows the brown color (contour lines) on the original DRG turned to yellow and all other colors turned to transparent (Figure 16). Many of the lakes in northern Wisconsin are very clear. A recent Secci depth reading for Blue Lake was 23 feet. In the bay depicted in Figure 17, one can see many interesting patterns of what appears to be submerged aquatic vegetation. In addition, the digital orthophotos may be displayed together with vector themes showing structures and parcel boundaries. Since the digital orthophotos were produced after the digital planimetric maps, they may be used to identify recently constructed buildings.

Figure 15: Digital Orthophoto and Digital Raster Graph

Figure 16: Digital Orthophoto with Contour Lines from DRGs

Figure 17: Digital Orthophoto with Buildings to Identify New Construction


Hot Links to Photographs of Shoreside Structures

Oneida County is interested in the use of visual imagery such as photographs or boat-based or aerial-based videography to aid enforcement and administration of the county shoreland ordinance. Figure 18 shows the use of hot links to relate scanned photographs of structures to their location on the shore of Blue Lake.

Figure 18: Visual Inventory of Structures on the Lake (Hot Links)


Acknowledgments

Much of the background information on lake management and rural zoning in Oneida County was extracted from a Wisconsin Department of Natural Resources (WDNR) Lake Protection Grant proposal for shoreland zoning compliance assessment prepared by Oneida County staff. Bryan Pierce, the Vilas County UW-Extension Community, Natural Resources, and Economic Development (CNRED) Agent and John Czarnezki, the Oneida County UW- Extension CNRED Agent both provided information on shoreland zoning concerns in the northern lakes district. The spatial data sets used in the application come from a variety of sources. Building outlines and hydrography were obtained from Mike Romportl, the Oneida County Land Information Officer. Parcels were digitized by staff of LICGF from county paper maps. Digital wetland maps were obtained from the WDNR. Digital orthophoto quarter quads (DOQQs) were produced by the U.S. Geological Survey and obtained from Ken Lubich in the Madison office of the Natural Resources Conservation Service. Digital raster graphs (DRGs) were obtained from Lance Perry in the Bureau of Information Management, Geographic Services (BIM/GEO) section of WDNR and represent another U.S. Geological Survey product. The property and permit attribute files were provided by Lynn Grube of the Oneida County Data Processing Department. Photo images of Blue Lake were taken in October 1996 by David Hart of LICGF. Finally, a digital copy of the Oneida County Zoning and Shoreland Protection Ordinance was obtained from John Czarnezki and developed into a Windows help file using RoboHelp 3 from Blue Sky Software. Techniques in using RoboHelp and integrating zoning ordinance text into ArcView were taught by J.D. Overton of the ESRI-St. Louis office.


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Last modified by David Hart on August 6, 2003.