U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2006–3033

August 2006

Evaluating the Effects of Nearshore Development on Wisconsin Lakes

Printed on recycled paper

Why are the effects of development 

a concern?

The Wisconsin Department of Natural Resources (WDNR) 

has estimated that the amount of development along Wisconsin 

lakes in the last 30 years is greater than that which occurred in the 

previous 100 years, and that as much as 90 percent of the private 

land adjacent to lakes and rivers will be developed by the year 

2025 (WDNR, written commun., 2005). The rapid rate of shoreline 

development in Wisconsin has raised concerns that future development may impair water quality in lakes. Development can increase 

runoff volume as well as sediment and pollutant loads. One nutrient 

associated with runoff is phosphorus, which is often responsible for 

increased algae in lakes (Robertson and others, 2005). For example, 

at one Wisconsin lake, runoff accounted for about 4 percent of the 

water flowing into the lake but 51 percent of the total phosphorus 

input (Garn, 2002). Development may also reduce water that sustains the ground-water system (ground-water “recharge”) and may 

adversely affect springs that feed a lake (the cold water you feel 

while wading near the shore). Surface runoff, reduced ground-water 

recharge, and lake impact are interrelated, and movement of water 

between these systems varies seasonally or even daily depending 

on changing conditions. Mitigating adverse effects after development has occurred along a lake can be expensive and difficult. 

Overlying these concerns are issues such as stewardship of the 

resource, the rights of the public, and landowners’ rights—both for 

those developing their land and those whose land is affected by this 

development. When there are contradictory goals, a scientific basis 

for assessing effects of development and effectiveness of mitigation 

measures helps ensure fair and constructive decision-making. 

To better assess the effects of development on lakes, the U.S. 

Geological Survey and the WDNR have conducted several studies 

on how nearshore development affects flows of water and nutrients 

to lakes. This Fact Sheet discusses the results of these studies.

How were the studies designed?

In the initial work by Graczyk and others (2003), a paired 

sampling approach was used, whereby adjacent developed (lawn) 

and undeveloped (woods) areas were monitored on four lakes in 

north-central Wisconsin from 1999–2001 (fig. 1). The developed/

undeveloped pairs were characterized with respect to their ability 

to infiltrate water and their loading of nutrients to the lakes. The 

study included measurements of: rainfall; surface runoff and water 

quality; ground-water flow and water quality; ground-water levels; 

soil temperature; and soil-moisture data. Water-quality sampling 

focused primarily on the nutrients nitrogen and phosphorus. 

Based on results from the initial study, two lakes, one in 

Walworth County, Wisconsin, and one in Chippewa County, Wisconsin (fig. 1), were later monitored to identify how water moved 

through the shallow soil and how vegetated buffers influenced this 

flow (Graczyk and Greb, 2006). During this study, vertical shallow 

soil-moisture profiles were measured along transects that included 

an upslope lawn, an intermediary vegetated buffer, and a downslope 

wooded site. The measurements were collected under natural 

rainfall conditions and controlled water additions. The datasets 

collected during this study provided insight into the small-scale 

processes operating at the developed and undeveloped sites.

What the studies found

Identification of changes in water flows and soil 

conditions at the small catchment scale 

The surface-runoff volumes from the wooded catchments were 

quite low (0 to 0.5 percent of the precipitation falling on the catchment). At one undeveloped site, no runoff occurred during the entire 

study period (October 1999–September 2001). Surface runoff from 

Figure 1. Location of data-collection sites: 1–Vilas, Forest, and Oneida 

Counties (Graczyk and others, 2003); 2–Chippewa County (Graczyk and 

Greb, 2006); and 3–Walworth County (Graczyk and Greb, 2006).

WISCONSIN

1

2

3

Eagle

River

0

0 30 60 KILOMETERS

30 60 MILES

Wells were installed for 

ground-water sampling using 

a soil probe mounted on a 

four-wheel drive all-terrain 

vehicle. This allowed the 

wells to be installed with 

minimum disturbance in the 

lawn and wooded sites, and 

ensured shallow and deep 

ground water was included in 

the sampling.
the developed lawn catchments, however, was generally 10 or more 

times higher than that from the wooded site runoff (fig. 2). Average 

lawn runoff varied from a low of 0.2 percent to a high of 6 percent 

of precipitation, with the highest value measured on the least-permeable soils. Lawn sites also had more runoff events during the 

study (average of 18.5 per site) than the companion wooded sites 

(average of 11.2 per site). The low runoff observed in the wooded 

catchments was likely a result of a number of factors: (1) the tree 

canopy intercepted a portion of the precipitation, which reduced the 

intensity and enhanced evaporation of the rainfall; (2) the relatively 

uncompacted organic-matter layer at the ground surface reduced 

rainfall impact and absorbed rainfall; and (3) increased permeability 

in the upper soil due to bioturbation (for example, worm holes) may 

have allowed most of the precipitation to infiltrate.

Conditions measured in soils at the sites also suggest differences in factors that may affect infiltration. During the growing season, soils in the lawns are warmer than soils in the woods because 

of reduced shading and increased solar radiation. Worms and other 

burrowing animals are likely to be more frequently found in the 

cooler, shaded areas rather than in the warmer lawn areas. Soils in 

the wooded sites were commonly moist. At the lawn sites, however, 

soil moisture depended on position in the catchment. Soil moisture 

measured under the lawn on a slope was drier than that measured at 

the adjacent wooded site. Soil moisture measured under a flat lawn 

site downhill from a lawn slope was higher than that measured in 

the adjacent wooded site on a slope, reflecting the addition of water 

generated in the lawn upslope. These results suggest that the effects 

of nearshore development depend on the type of landscape next to 

the lake. Lawns on slopes that end at the lake can be expected to 

add additional runoff directly to the lake. Lawns that end in flat 

areas or buffers, on the other hand, may not result in increased 

runoff to the lake because these areas often have a greater ability to 

infiltrate runoff.

Identification of changes in nutrient flows at the small 

catchment scale

For equal-sized areas, the amount of nutrients exported by surface-water runoff was greater from the developed lawn catchments 

than that from the undeveloped woods at all sites for all nutrients 

studied (fig. 3). This increase in nutrient loading to the lake held 

true for all nutrients measured. For nitrate plus nitrite, Kjeldahl 

nitrogen, and total phosphorus, the developed lawn loading was 

10 to 100 times more than the undeveloped woods loading. Higher 

loads were not a result of higher nutrient concentrations in the lawn 

runoff, however. Instead, the lawn sites had higher runoff frequency 

and volume, which resulted in more nutrient-carrying water leaving 

the catchment.

The ground-water system also carried appreciable concentrations of nutrients to the lakes. Ground water under the lawn areas 

had concentrations of nitrate and total phosphorus 3 to 4 times 

higher than concentrations measured in ground water beneath the 

wooded catchments. The highest concentrations of these nutrients 

were measured in the lawn site in a flat area downslope from a 

lawn slope. This finding suggests that higher rates of lawn runoff infiltration such as those noted above can result in enhanced 

nutrient loading to the ground-water system, and subsequently to 

the lake, even if the runoff itself does not reach the lake. Elevated 

nutrient concentrations were also noted in deeper ground water 

beneath both types of catchments, reflecting land use in areas more 

distant from the lake. Ground-water modeling in Graczyk and others (2003) also demonstrated the importance of these distant areas 

for supplying ground water to the lake (fig. 4). Thus, a lake can be 

affected by land use in somewhat distant areas even if they do not 

contribute surface runoff to the lake. Moreover, because it takes 

time for ground water to travel from distant areas to the lake, there 

is a lag between the time land-use changes occur and when these 

changes are observed in ground water flowing into the lakes. Accurate long-term estimates of the effects of changing land use would 

need to account for this lag.

Evaluation of water infiltration and the importance 

of buffers

Additional insight into how runoff and buffers interact was 

gained using the soil-moisture profile transects instrumented in 

2003–2005 (Graczyk and Greb, 2006). In a controlled water-addition experiment, a downspout was simulated by adding water as a 

point discharge to a lawn and tracking soil moisture downslope. The 

volume of water added to the lawn was approximately equivalent 

to a 2-inch rain falling over a 6-hour period on a 2,200 square-foot 

impervious area, which might include roofs of houses and garages, 

driveways, and patios. The added water moved horizontally as well 

as vertically, showing up 25 feet downslope in less than 3 hours at 

the lawn/woods buffer contact at depths greater than 8 inches (fig. 

5). No indication of the water addition, however, was observed at 

0

10

20

30

40

Lawn

(n=4 sites)

Woods

(n=6 sites)

PERCENT RUNOFF

Maximum = 34 percent

Maximum = 2 percent

Average = 3 percent

Average = 0.2 percent

Figure 2. Percent of 

precipitation converted to 

runoff for events measured 

during the study, October 

1999–September 2001. The 

amount of runoff generated 

from a given rain volume was 

significantly higher at the lawn 

sites than at the wooded sites 

(p <0.05)(Graczyk and others, 

2003).

0.0

0.1

0.2

0.3

0.4

0.5

0.6

NUTRIENTS EXPORTED (IN POUNDS PER ACRE)

Maximum

Average

Ammonia

nitrogen

Nitrate

plus

nitrite

nitrogen Kjeldahl

nitrogen

Dissolved

phosphorus

Total

phosphorus

Lawn Woods Lawn Woods Lawn Woods Lawn Woods Lawn Woods

Figure 3. Median amount of nutrients exported normalized by area 

for events measured during 1999–2001. Results from the wooded sites 

were significantly lower for all nutrients (p <0.05)(Graczyk and others, 

2003).
the next measurement point an additional 25 ft downslope (fig. 5), 

reflecting the smaller water volume as well as the higher infiltration 

capacity within the buffer. The flat portions of the curves in figure 5 

indicate times when the soil was saturated and the ability to transmit 

water was greatest. Although the lawn site had the maximum ability to infiltrate at all depths during the test (as indicated by the flat 

slopes in the soil moisture curves in figure 5), the water added from 

the simulated impervious area was more than could be infiltrated, 

resulting in horizontal flow within the soil downslope toward the 

lake. Larger water volumes, such as those that would result from 

larger impervious areas, would increase this flow. In contrast, reducing the amount of impervious area that contributes water (equivalent 

to reducing the amount of water added in the experiment) would 

decrease the amount of horizontal flow toward the lake. The fact 

that runoff traveled more than 25 feet under the lawn (fig. 5), but 

then was infiltrated before it traveled the next 25 feet in the buffer, 

underscores the importance of an appropriate land-use setback from 

a lake or stream. Larger setbacks with native vegetation buffers 

would increase the likelihood that high-intensity rainfalls would be 

infiltrated before entering a lake. 

Implications for lakes

The results of the studies demonstrate that the conversion of 

undeveloped wooded areas into lawns can significantly affect both 

flow of water and nutrients to lakes. Large increases in lawn nutrient contributions were due to increased runoff volumes; therefore, 

reducing runoff to a lake is critical for minimizing adverse effects. 

Reducing the amount of impervious area increases the amount of 

land available for infiltration and reduces the water added to local 

areas within a site, which in turn helps ensure that the soil’s ability to infiltrate water will not be exceeded. Appropriate setback 

Study methods and site description

Approximately 10 feet

TOP VIEW

Stand

Submersible

pump NOT TO SCALE

Ground

surface

Ground

surface

Sample

container

Diverter

CROSS-SECTIONAL VIEW

Drain tube

Tipping bucket

(buried)

Sample

hose

Direction of flow

5-gallon bucket

Lawn edging

5-gallon

bucket

Drain tube

Tipping

bucket

A paired sampling approach was used 

in this study. For the 1999–2001 monitoring, 

areas of adjacent developed and undeveloped 

areas were simultaneously monitored on four 

lakes in north-central Wisconsin (Graczyk 

and others, 2003). The developed catchments 

consisted mainly of lawns; the undeveloped 

catchments consisted of varying mixtures of 

mature and immature deciduous and coniferous woods. Precipitation, surface runoff and 

water quality, ground-water flow and water 

quality, ground-water levels, soil temperature, 

and soil-moisture data were collected from the 

small (85 to 1,080 ft2

) catchments. To determine 

variability within sites, multiple undeveloped 

and developed subcatchments were monitored 

within each site. 

The quantity and quality of surface-water 

runoff were sampled using below-ground 

sample bottles. Runoff was directed into the 

bottles using 10-ft-long barriers installed on the 

ground surface using 0.5-in PVC pipe with slots 

or plastic lawn edging driven into the ground 

(see diagram at right). The barrier was placed 

perpendicular to the slope, so that surface runoff was intercepted and drained into collector 

bottles that were buried nearby. The samplers 

were checked weekly by a local observer and 

after rain and snowmelt events. Samples were 

analyzed at the Wisconsin State Laboratory of 

Hygiene; water volumes collected from each 

storm were coupled with the corresponding 

concentration data to determine areal loads 

and yields.

In the 2003–2005 sampling, a lawn, 

vegetated buffer, and wooded site were 

instrumented with a vertical profile of sensors 

that measured soil moisture. The soil-moisture 

probes were placed in a line that traversed 

a lawn to a wooded buffer to determine both 

vertical and horizontal movement of water. 

At each probe, soil moisture was monitored 

10 cm, 20 cm, 30 cm, 40 cm, and 50 cm below 

the land surface. In addition, a tipping-bucket 

raingage was installed at each site to determine rainfall. Measurements were collected at 

1-hour intervals and included time periods that 

encompassed natural rain events. A controlled 

experiment was also performed during which 

known volumes of water were added to lawn 

and wooded areas.

Lower

Ninemile Lake

Butternut Lake

Capture zone for 

Lower Ninemile Lake system Capture zone for 

Butternut Lake system

EXPLANATION

Wetland

Lake

Stream

0 1 2 MILES

0 1 2 KILOMETERS

45°58' 45°52'

89°07' 88°56'30"

Figure 4. Model simulated ground-water capture zones for two 

lakes demonstrate that lakes receive water from distant areas as well 

as nearshore areas. A lake’s capture zone also includes areas that 

contribute water to the streams that flow into a lake. Given sufficient 

time, lakes are affected by land-use change that occurs anywhere 

within their capture zone (modified from Graczyk and others, 2003).
distances and buffers between impervious areas and lawns and lakes 

are important because they enhance a site’s ability to absorb water 

before it is conveyed to a lake. Areas with slopes draining directly 

into a lake are expected to have the highest runoff amounts and 

associated nutrient loading. Lawns where slopes do not terminate at 

a lake, and areas with intervening flat or buffer zones between the 

lawn and a lake are more apt to infiltrate runoff, thereby reducing 

potential adverse effects on a lake.

Ground water was also affected by the degree of development. Both nearshore areas and distant areas supplied ground water 

and ground-water-transported nutrients to the lakes. Thus, lake 

protection should have a watershed focus in addition to a focus on 

nearshore areas. Moreover, understanding the effects of distant areas 

may be important for lake protection in the future as off-lake development increases and developable nearshore land becomes scarce.

 It should be noted that the areal nutrient loading rates in lawn 

and woods sites calculated in this work were generally less than 

those found in the previous studies. The difference is likely due to 

generally larger catchment areas investigated in the other studies, 

which incorporated added runoff volumes from impervious source 

areas, such as driveways and rooftops (Steuer and Hunt, 2001). In 

addition, development often results in compacted and disturbed 

soils (Owens and others, 2000) that can reduce infiltration of runoff. These factors would augment the effects of the lawn land use 

evaluated here. 

Finally, the focus of this work was on comparisons of individual catchments that feed lakes; the cumulative effect of multiple 

developments on a lake was not studied. However, the resiliency of 

a lake can change with time as additional development occurs 

(Carpenter, 2003), much like a boxer withstanding a punch in the 

first round only to be knocked out by a similar punch in a later 

round. How a lake has responded in the past to land-use change 

may not reflect how it will change in the future (Hunt, 2003). This 

complexity underscores the need for sound watershed-scale understanding of systems rather than only depending on the approaches 

of the past. With such an understanding, decision-makers will be 

better able to protect water resources for generations to come.

References

Carpenter, S.R., 2003, Regime shifts in lake ecosystems: pattern and variation, 

in Kinne, O., ed., Excellence in ecology, Book 15: International Ecology 

Institute, Oldendorf/Luhe, Germany, 199 p.

Garn, H.S., 2002, Effects of lawn fertilizer on nutrient concentration in runoff 

from lakeshore lawns, Lauderdale Lakes, Wisconsin: U.S. Geological Survey 

Water-Resources Investigations Report 02–4130, 6 p.

Graczyk, D.G., and Greb, S. R., 2006, Soil Data at Sites near Geneva Lake, 

Lake Geneva, Wisconsin, and Long Lake, near New Auburn, Wisconsin: 

U.S. Geological Survey Open-File Report 2006–1191, 10 p., 2 digitial 

appendixes, accessed July 20, 2006 at http://pubs.usgs.gov/of/2006/1191/

Graczyk, D.G., Hunt, R.J., Greb, S.R., Buchwald, C.A. and Krohelski, J.T., 

2003, Hydrology, nutrient concentrations, and nutrient yields in nearshore 

areas of four lakes in northern Wisconsin, 1999-2001: U.S. Geological Survey Water-Resources Investigations Report 03–4144, 64 p.

Hunt, R.J., 2003, A water science primer: Wisconsin Academy of Sciences, Arts 

and Letters Transactions, v. 90, p. 11-21.

Owens, D.O., Jopke, P., Hall, D.W., Balousek, J., and Roa, A., 2000, Soil 

erosion from two small construction sites, Dane County, Wisconsin: U.S. 

Geological Survey Fact Sheet FS–109–00, 4 p.

Robertson, D.M., Rose, W.J., and Saad, D.A., 2005, Water quality, hydrology, 

and phosphorus loading to Little St. Germain Lake, Wisconsin, with special 

emphasis on the effects of winter aeration and ground-water inputs: U.S. 

Geological Survey Scientific Investigations Report 2005–5071, 36 p.

 Steuer, J.J., and Hunt, R.J., 2001, Use of a watershed-modeling approach to 

assess hydrologic effects of urbanization, North Fork Pheasant Branch Basin 

near Middleton, Wisconsin: USGS Water-Resources Investigations Report 

01–4113, 49 p.

Acknowledgments

The authors acknowledge the assistance of the land owners who graciously allowed us to install equipment and monitor 

surface- and ground-water flow on their properties. We are also 

grateful for the assistance of Sandra S. Gillum in initially locating 

the sites and assisting with data collection and Theodore W. Peters 

(Director, Geneva Lake Environmental Agency, Lake Geneva, 

Wis.) and Patrick “Buzz” Sorge (WDNR) for locating sites in Walworth and Chippewa Counties, respectively.

Authors: Randall J. Hunt, Steven R. Greb (WDNR), and David J. Graczyk

What landowners are doing to limit the effects of 

development on lakes:

• Maintaining a natural landscape with native vegetation

• Leaving or maintaining buffer strips (WDNR currently (2006) 

recommends at least 35 feet)

• Not installing lawns on slopes that drain to lakes

• Not adding fertilizer to lakeshore lawns

• Limiting the amount of impervious areas on their site such as 

sidewalks, driveways, and rooftops

• Reducing erosion

• Enhancing infiltration of runoff from rooftops, driveways, and 

other impervious areas

• Not removing woody vegetation from nearshore areas

• Installing rain gardens to enhance runoff infiltration

Lawn site

0

10

20

30

40

50

60

WATER CONTENT,

IN PERCENT

water application

soil saturated

Lawn/woods buffer site

0

10

20

30

40

50

60

WATER CONTENT,

IN PERCENT

soil sat soil saturated rated

water application

Woods site

0

10

20

30

40

50

60

8/18/03 10:008/18/03 16:008/18/03 22:008/19/03

4:00

8/19/03

10:00

WATER CONTENT,

IN PERCENT

water application

Water on at 10:48

Water off at 16:42

7.7 gal/min – 0.017 ft3

/s

2,726 gal – 361 ft3

10-cm depth

20-cm depth

30-cm depth

40-cm depth

50-cm depth

Figure 5. Soil-moisture profiles for the Walworth County site for a 

water-addition experiment along a transect that included an upslope 

lawn site, an intermediary buffer site, and a downslope wood site 

(Graczyk and Greb, 2006).