A Demonstration Project

Landscape Design for a Lakefront Property on Crystal Lake Burnsville, Minnesota

Minnesota is truly a land of 10,000 lakes - lakes that play a major role in the quality of life for many Minnesotans. With a rising population, the quality of our lakes is being compromised by overuse and from the side effects of development. Both of these activities lead to an increase in erosion and additional nutrient-rich runoff that finds its way into the lakes. This, in turn, degrades water quality - both aesthetically and as wildlife habitat. With this problem in mind, a design was created in the spring of 1998 for an actual lakeshore property in a highly developed suburb of the Twin Cities metropolitan area. It is meant to be a working landscape design for the homeowners as well as a demonstration project for other landowners.

The subject of water quality is a complicated one involving many different players. Water quality control is everyone's responsibility - landowners and developers alike. Owners of property not directly adjacent to water play a role as well. Everything that lands in our streets and gutters will eventually make its way to a lake, stream or wetland through the stormwater sewer system. This includes leaves, grass clippings, and fertilizer, which add to the excess nutrient loads flowing into lakes, as well as spilled chemicals and motor oil. Water from stormwater systems is not treated before being discharged into a body of water. Additional information can be obtained from the Chain of Lakes Clean Water Partnership, 3800 Bryant Avenue South, Mpls, MN 55409.

This particular project will address these issues in regard to waterfront property. The design was done as a demonstration project to overcome functional and aesthetic concerns on the site through landscape design and landscape maintenance practices. The project's goals are:

• To provide information regarding the types of special considerations that need to be included in doing a landscape design for waterfront property;
• To look at the steps involved in doing a waterfront property design;
• To provide a working design allowing for family use of a waterfront property while incorporating techniques to improve water quality;
• To discuss maintenance practices that have an effect on water quality;
• To discuss the implementation of a waterfront landscape design;
• To provide a list of references for additional information.

General Considerations When Working With Lakefront Property

Because of the pressure placed on lakes by human development and the special functions of lakefront property, it is necessary to include additional information when completing both the site analysis and the site survey. Some of this information can be obtained from the landowner while other information will require contacting outside sources. Some things to consider are:

• Department of Natural Resources (DNR) regulations that include: how land below the high water mark is used or altered, restrictions and permits for the addition or removal of aquatic vegetation, erosion control techniques required, etc.;
• The DNR lake designation (recreational development, natural environment or general development);
• Protected water or wetland designations existing on the property;
• Local building ordinances that may include: setbacks from the lake; codes for stairways, docks, boat lifts, walkways and accessory buildings such as boat houses or gazebos; restrictions on removal of terrestrial vegetation between structures and lakefront; requirement for screening of structures from the lake; amount of nonporous surface area allowed, etc.;
• Winter storage areas for boats, boat lifts and docks;
• Normal lake level fluctuations: ordinary high and low water marks, record high and low water marks;
• Existing erosion problem and its effect on water quality;
• Homeowner's planned use of shoreline (swimming, boating, fishing, relaxation, wildlife viewing);
• Possible need for vehicle access to waterfront for boat landing or maintenance;
• Landscape management - use of fertilizers and pesticides.

Many of the above concerns can be addressed during the process of creating a base plan for the design. The client interview should include discussions about the special needs of the property such as winter storage areas and planned usage of the site. The site survey should include ordinary high and low water marks, moisture content of the soil, existing aquatic and shore vegetation and its value, slope to the shore, and any erosion problems. The site analysis needs to include qualifications on the site in regards to wetland, protected water, and lake type designations. The first two sources to be contacted in locating this type of information are the local DNR office and the zoning department at the local government office.

The Site

View the Base Plan

Problem Solving

After completing the site survey, site analysis and base plan it is time to move onto the landscape design sequence. Before starting the first step in the design sequence, bubble diagrams, it will be beneficial to go through the first three steps of the following problem solving sequence. This will determine exactly what problems need to be overcome, what the causes of those problems are and the role of government regulations and guidelines in developing possible solutions.

Step One: Determine what problems need to be addressed:

• Access to water
• Maintenance problems
• Nuisance waterfowl
• Aesthetics
• Reduction in water quality
• Privacy needs

Step Two: Determine causes of problems:

• Water access limited by steep slopes, eroding shore, excess aquatic plants, wet and/or soggy areas;
• Unable to maintain turf due to steep slopes or wet areas; unable to maintain shore due to erosion;
• Waterfowl coming onto property due to enhanced habitat such as mowed turf extending to the shoreline;
• Not aesthetically pleasing due to loss of natural vegetation, or aggressive growth of invasive species or erosion;
• Poor water quality due to sediments from shore degradation or excess nutrient runoff;
• Privacy lost by removal of vegetation.

Step Three: Gather information from regulating offices:

Before determining solutions for the defined problems, the regional DNR office and the local government zoning office should be contacted. This is true of all waterfront landscape designs and was done for this project. They will help determine if the project requires permits and/or additional input from the Army Corps of Engineers, the local conservation officer, the regional hydrologist or a watershed district. Phone numbers should be available in local phone directories or by calling the state office information number.

Information available from state DNR offices:

• Protected waters map (available at regional and area DNR offices, local soil and water conservation district offices or the county auditor's office);
• Guidelines and restrictions for work that can be done without permits (includes, but is not limited to: beach sand blankets, rock riprap for shore protection, debris removal, docks and floating structures, boat ramps, removal of structures and culverts);
• Control of aquatic plants (permit application, approved herbicides, estimated herbicide costs, list of licensed herbicide applicators and mechanical harvesters);
• Planting below ordinary high water level.

Information available from local zoning offices:

• Guidelines and restrictions for water-oriented accessory structures including requirements for screening from view
• Structure setbacks
• Limits on structure sizes and acceptable building materials
• Restrictions on removing existing vegetation between a residence and the shoreline
• Amount of non-porous surface area allowed
• Guidelines for stairways, lifts and landings
• Guidelines and permits for grading, filling or excavation
• Evaluation of steep slopes for erosion
• Treatment of bluff and bluff impact zone on property

There are also national wetland inventory maps available; see appendix for information on how to obtain Minnesota maps.

Step Four: Determine solution to problems:

• Make a list of possible solutions that fit criteria discussed above
• Pick specific solutions to be implemented
• Complete the four steps in the landscape design sequence:

  1. Bubble diagrams
  2. Concept plans
  3. Draft designs
  4. The complete landscape design
  

Landscape Design Strategy for Waterfront Property

As with all landscape designs, the waterfront property design should be functional, maintainable, cost effective, visually pleasing and environmentally sound. Waterfront properties typically present additional challenges. As seen above, there are more regulations regarding this type of property than for typical residential lots. These regulations are designed to protect water quality as well as the aesthetic value of lakes. Fortunately the methods to achieve these two goals are mutually inclusive as well as being beneficial to property owners by maintaining property values. Good information is available to demonstrate how this works. The University of Minnesota Extension Service has both a video and an information packet explaining shore land best management practices to "preserve water quality and the value of your shore land!" Another video, called "The Living Shores," uses computer animation to show what changes can occur when various management practices are implemented. This video was made as a cooperative effort by the University of Minnesota Extension Service, Minnesota DNR, Wisconsin DNR and University of Wisconsin Extension (see the appendix for ordering information). Following are three methods of achieving the above goals while being mindful of function, maintenance and long-term performance.

Method One: Include a vegetative buffer strip and aquascaping in the shoreline design.

Definition of buffer strip:

An area of native plants with limited maintenance to provide a buffer zone between development, including mowed turf, and the waterfront. A vegetative buffer strip can be composed of trees, shrubs, grasses, flowers or any combination of these. The width of buffer strips can vary but function will increase as width increases. A minimum of 15 to 25 feet is recommended; 30 feet will accommodate the needs of most shoreline wildlife. The Minnesota DNR has an excellent publication called "The Water's Edge" that discusses the importance of buffer strips, aquatic vegetation and wetlands (6).

Functions of buffer strips:

• Improve or maintain water quality by providing a filter area to trap sediments and excess nutrients
• Improve wildlife habitat
• Restrict access to lawns by geese
• Reduce maintenance time and cost
• Preserve natural beauty of a setting
• Provide for privacy
• Screen undesirable views and frame good views
• Provide erosion control and shoreline stabilization

Definition of aquascaping:

This is a new term that is still in the evolutionary stage. Two definitions are: 1. Landscape design of shoreline including moist, wet and aquatic areas.
2. Landscaping in or adjacent to wet areas using aquatic, wet meadow and upland plants tolerant of wet soils to create a naturalized shoreline.

Other terms in use are shorescaping and lakescaping. Ideally an aquascape design will be incorporated into a complete landscape plan. The intent of aquascaping is to include plant material in a shoreline design that will allow for recreation, be aesthetically pleasing, and at the same time, help manage water quality. This portion of the plan should be included in the entire planning process - from bubble diagrams to concept plans to draft designs and the completed landscape design.

More information on aquascaping is available in the Minnesota DNR's March/April 1998 issue of The Minnesota Volunteer (see appendix), "Shorelandscaping" from The Wisconsin Lakes Partnership (1) and "Aquascaping: A Guide to Shoreline Landscaping" from the Hennepin Conservation District; there is an excellent aquascaping video to accompany this publication (2).

Method Two: Practice erosion control and reduce nonporous surfaces.

Erosion control can be a complicated issue and needs to be customized for each landscape project. Consult with the DNR and local building ordinance office for assistance.

Whenever possible, keep nonporous surfaces to a minimum. A nonporous surface is one that will not allow water infiltration such as blacktop, concrete and rooftops. Runoff water from these surfaces provides a potential means for pollutants and excess nutrients to be carried into bodies of water. Nonporous surfaces can be reduced by using porous materials, such as wood chips, for pathways and mulch. Occasional use parking and vehicle turn-arounds can be constructed of turf that incorporates porous pavers or mesh (see appendix for material and application information).

Method Three: Choose plant materials that are adapted to site conditions.

The choice of plant materials will play a vital role in determining how well a landscape functions, how well the design's goals are met and the long-term sustainability of the design. Whenever possible it is advantageous to use native plants appropriate to the site's growing conditions. Although using native plants is not always possible or desirable they generally:

• are better adapted to a site's growing conditions
• are reliably winter hardy
• require less long-term maintenance
• blend in well with undeveloped areas along the shoreline

Three rules of thumb regarding plant choice are:

Another consideration in shoreline plant selection is size for the maintenance of attractive views and to screen undesirable views. Taller plant material can be used on either side of a pleasant view to create a frame and enhance the view. These same plantings can be used to screen power lines or a neighbor's storage area. When choosing a plant height to avoid obstructing a view, remember to take into consideration the difference in elevation between the shoreline and the viewing area, often a deck or porch. In this demonstration project the porch and patio are seven feet above the lake level. Any plantings less than seven feet will not interfere with the view. If mature trees have a few lower limbs removed, it is usually possible to see under the tree's canopy.

Even the type of grass used in areas of mowed lawn can be selected for low maintenance; not all grasses are created equal. As much care should be given to choosing the correct grass as is given to other plant materials. The amount of sunlight, as well as the type of use for an area, will determine the best grass mix to select. Using a grass that will perform well and provide a thick, healthy lawn will allow for maximum infiltration of runoff water. The county extension office can give guidance in grass selection. Although mowed turf can prevent erosion and increase water infiltration, it doesn't always perform all the other functions desired in a plant material. In or near the water, plants are used to filter sediment, take up excess nutrients, provide wildlife food and habitat, and shade shallow water to reduce temperature fluctuations.

Upland plants can also be used to provide wildlife food and habitat, provide privacy, screen undesirable views, frame pleasant views and provide shade. Information concerning plant selection and plant sources can be found in Minnesota and Wisconsin extension publications (3), Landscaping for Wildlife (4) and Aquascaping: A Guide to Shoreline Landscaping (2). See appendix for additional plant sources.

Landscape Maintenance to Protect Surface Water Quality

How This Design Works to Address the Needs and Considerations of a Waterfront Property

Refer to the base and implementation plans to see how following the proposed landscape changes can work to meet the special needs of both this project and waterfront projects in general.

-A large asphalt parking area is to be removed and replaced with a smaller turn-around and visitor parking area using a porous paving material (see appendix for choice of materials).

-Turf along the south lot line is to be removed and replaced with shrubs and ground covers to eliminate difficult mowing between trees along the lot line.

-Space will be allowed to drive a vehicle between the garage and the added plantings to provide access to the shoreline and back yard.

-Vegetative screening is added in the front yard as a buffer from the street.

-A screened porch and gazebo are incorporated in the design to provide mosquito-free areas to enjoy the lake view.

-Turf maintenance in a low, and sometimes wet, area near the lake will be eliminated by a combination of grading to create a higher, flat play area bordered by a boulder retaining wall and planting a wet meadow below the boulders.

Details of the Aquascaping Plan:

-The grade below the two trees down slope from the house will be raised about 12 inches and bordered with a natural boulder retaining wall comprised of one row of 18-inch boulders. This will not only eliminate a problem wet area but will also provide the only flat area on the lot for volleyball, etc.

-The area below the boulder wall will be aquascaped as a wet meadow. This will create a vegetative buffer strip, eliminate maintenance of turf in this sometimes wet area and return the shoreline to a more naturalized setting. The wet meadow will be in a dip behind the lake ridge line. Short, native woody plants will be included in the meadow area to help hold soil and strengthen the design. The homeowners requested that no large woody plants be added to this area.

-Moisture-loving forest perennials will be planted under the existing trees along the south lot line and create a transition area from the more formal upland portions of the design to the more naturalized shoreline area. A path to the dock will angle through the plantings so there isn't a straight line break in the buffer zone.

-Ornamental native aquatic plants will be re-established to create a more natural shoreline and improve water quality by reducing erosion and filtering runoff water.

-A portion of the shoreline will be left open as a beach area for play and beaching a catamaran but will still be protected by the buffer strip above it.

-The gazebo will be slightly elevated due to moisture concerns and vegetatively screened from the lake.

-Use of herbaceous plants in the buffer strip will allow for winter dock storage. Woody plants will be kept to the side of the storage area.

The local zoning office and the DNR were consulted regarding the proposed plan.

View the Completed Landscape Design

Implementation

Implementation of the design will need to be carefully planned before work begins to avoid erosion problems. Some possible erosion control techniques are:

• Erection of an erosion control fence between the area being planted and the shoreline;
• Keeping areas of plantings lower on the slope intact while working on higher areas so the entire area is not bare at one time;
• Leaving turf near the water intact until regrading and re-establishment of turf in the play area is completed;
• Use landscape fabric behind the boulder wall to prevent soil from washing through;
• Use sod rather than seeding to avoid bare soils.

Removal of the turf in the wet meadow can be done with a turf cutter during a dry period or killed chemically with rodeo, a product similar to Round-Up that is labeled for use in wet areas. Consider using bare-root stock for woody species to reduce costs. These need to be planted early in spring and may require calls to several nurseries to locate plants.

Note: All plants in wet areas should be native and non-invasive. The local DNR office can advise on plant choice.

Planting Techniques For the Wet Meadow and Aquatic Areas

Planting of herbaceous materials can be done with plugs or larger plants by cutting holes in the dead turf. This will prevent erosion while new plants become established. If it is desired to till in the dead turf, new plantings will need to be well mulched. Alternatively an erosion mesh can be used with holes cut in it to accommodate new plantings. It would also be possible to seed the area to reduce costs and eventually have a more dense stand of plants. A disadvantage of this method would be a longer establishment time. If seeded, a custom mix of seeds should be used to best meet the needs of a particular site. A combination of seeding and plugs could be done as a compromise, giving some immediate gratification and still keep costs down. Either way, the homeowner needs to be patient and understand that it may take up to three seasons before the area looks completed.

Many species need to be used in the water and in the buffer strip. It is not certain which species will work best in a particular site so several need to be tried. This will also give a longer bloom time and foliage interest period. Eventually the plants will sort themselves out according to the sun and moisture regiment best suited to them. While becoming established it will be necessary to watch for undesirable volunteer plants. These need to be removed so they won't push out the new plantings. Aquatic and wet meadow plantings cannot be considered a static garden. It will be ever changing which adds to its interest.

Aquatic plants are generally easier to establish in times of low water levels. Once established they will better tolerate higher water levels. Plants that are put directly in deep water, such as water lilies, can benefit from being anchored until they are established. Depending on wave action at a particular site, it may be necessary to install wave breakers until plants are established (see aquascaping article in the appendix).

Professional consultants are available to aid in the implementation of an aquascaping plan. Check with local regulatory offices to find names of firms or look in the yellow pages under Environmental and Ecological Services. Be sure to thoroughly check a company's references and confirm that they have the kind of experience the project requires. It would be prudent to visit an implementation site that the company has completed.

Summary

This demonstration project should:

• Raise awareness of the special considerations that need to be addressed in a waterfront design;
• Illustrate ways to incorporate shoreline design and aquascaping into a complete landscape plan;
• Show examples of how to overcome the design challenges presented by the need to balance a homeowner's requirements with lake quality protection. These two goals need not be mutually exclusive.

Although residential landscape design and maintenance is only one piece of the puzzle affecting water quality, it plays an important role. This issue can be addressed by individual homeowners or, more effectively, by groups of property owners through a lake or homeowners association. The materials listed in the reference section and the appendix, particularly the videos, are excellent educational tools to use at association meetings.

References

1. Shorelandscaping, Wisconsin Lakes Partnership, University of Wisconsin Extension.

2. Aquascaping: A Guide to Shoreline Landscaping. Carolyn Dindorf. 1993. An aquascaping video is also available.

3. University of Minnesota Extension Service

4. Landscaping for Wildlife. MN Department of Natural Resources. St. Paul, MN. 1987.

To locate your regional Minnesota DNR office call 651-296-2835 or 1-800-766-6000

5. Turfgrass Management For Protecting Surface Water Quality
Lawn Care Practices to Reduce the Need for Fertilizers and Pesticides
Responsible Use of Lawn Care Pesticides
University of Minnesota Extension Service. 1995.

6. The Water's Edge. MN DNR. 1998.

To receive a copy call the DNR Section of Ecological Services (651) 296-2835.
Also request a copy of the free Guide to Aquatic Plants

Appendix

Sources of Information Regarding Shoreland Management - Regulations and Guidelines

1. "The Living Shores" video

The above is also available from the University of Minnesota Extension Service.

2. "Keeping Our Shores, Shoreland Best Management Practices" video and "Protecting Our Waters, Shoreland Best Management Practices" - packet of 18 publications

Call University of Minnesota Extension Service 1-800-876-8636 or see attached order form.

Four additional videos are part of the above series from the University of Minnesota Extension Service; "Keeping Our Shores," "Water Conservation," "Septic Systems" and "Erosion Control."

3. University of Minnesota and University of Wisconsin Extension Services publications

See reference section

4. University of Wisconsin-Extension
Lake Management Specialists
College of Natural Resources
University of Wisconsin
Stevens Point, WI 54481
(715) 346-2116

5. Wisconsin Association of Lakes
P.O. Box 2064
Madison, WI 53701
(608) 233-2227 or 1-800-543-5253

6. Wisconsin Department of Natural Resources
Lake Management Section
Bureau of Water Resources Management
P.O. Box 7921
Madison, WI 53707
(608) 266-0502

7. U.S. Army Corps of Engineers
St. Paul District
180 Kellogg Blvd E., Room 1421
St Paul, MN 55101-1470
(651) 290-5376

8. To locate the appropriate Minnesota DNR office:
Call 651-296-2835 or 1-800-766-6000

9. To locate the proper local office for regulations and guidelines: in a city or village, call the city hall and ask for the building inspector or local zoning office. In an unincorporated area, call the county courthouse and ask for the county zoning office.

10. For information on how to order a Minnesota National Wetlands Inventory Maps Index contact:

Minnesota's Bookstore
117 University Ave.
St. Paul, MN 55155
612-297-3000 or 1-800-657-3757
FAX 612-296-2265

This index will also list other wetland information sources.

Note: Many localities have ordinances that supersede state regulations so always check both levels of government.

Porous Paving

Geoblock from:
Presto Products Company
P.O. Box 2399
Appleton, WI 54913
800-548-3424

Netlon from:
Glenn Rehbein Companies
8651 Naples St. NE
Blaine, MN 55449
(612) 784-0657

Plant Material Sources

Minnesota Native Wildflower/Grass
Producers Association
Rt 3, Box 163
Winona, MN 55487

Wildlife Nurseries
P.O. Box 2724
Oshkosh, WI 54903

Lee Nursery, Inc
Fertile, MN 56540

Hild & Associates
326 Glover Road South
River Falls, WI 54022
800-790-9495

Landscape Alternatives
1705 St. Albans St.
Roseville, MN 55113
(651) 488-3142

Taylor Creek Restoration Nurseries
17921 Smith Road
P.O. Box 256
Brodhead, WI 53520
(608) 897-8641

Prairie Moon Nursery
Route 3, Box 163
Winona, MN 55987
(507) 452-1362

Prairie Restorations, Inc
P.O. Box 327
Princeton, MN 55371
(612) 389-4342

Prairie Nursery
P.O. 306
Westfield, WI 53964
(608) 296-3679