Cost-Benefit Analysis of Riparian Buffers
Lisette Solis, University of California Berkeley
Faculty Advisor: Dr. Chris Ferguson, University of Wisconsin-Stout
Introduction:
Yearly buffer strip mitigation potential:
Dunn County passed a more restrictive version of this ordinance allowing only
15’ of the viewing window to be mowed. With the passage of the 2015-2017
State budget counties can no longer adopt standards that are more restrictive
than those dictated by the NR 115, overturning the County ordinance.
o Tainter with no access corridors
99,393 ft. circumference x 35 ft buffers=3,478,755 square ft=80 acres
.65 lbs P
80 acres x
x 80% buffer efficacy=41.6 lbs P
acre
500 lbs algae
41.6 lbs P x
=20,800 lbs algae
1 lb P
o Tainter with 15’ access corridors as required by County Ordinance
71.6 acres ;37.2 lbs P; 18,616 lbs algae
Wisconsin Zoning Regulations, NR 115, set minimum standards for counties
requiring 35’ buffer zones with a maximum 30’ per 100’ viewing window. These
policies are intended to help reduce the runoff of phosphorous and sediment
from yards and farms.
o Tainter with 30’ access corridors as required by NR 115
12% less buffer; 33.1 lbs P; 16,536 lbs algae
This project investigates:
o Willingness of waterfront homeowners to install buffer strips
o The possible benefits of riparian buffers
o The differences in mitigation potential between the State standards and
those adopted by Dunn County
A buffer strip is a non-mowed
area of natural shrubs, grasses, and
trees that help filter runoff and
hold soil in place. It is believed that
35 foot buffers along the shoreline
can help reduce the runoff of
phosphorous and sediment from
yards and farms.
Methods:
Mailed 473 surveys out to home owners along the Red Cedar River, Lake
Menomin, and Lake Tainter. Received 136 surveys in return (28.8%
response rate). Survey comprised of questions about lake use, yard use,
and yard maintenance practices.
GIS analysis of shoreline acreage conducted using Department of Natural
Resources data and incorporating data from Dunn County Land and Water
Division estimating the extent of buffer strip adaptation on Tainter Lake.
Collected 158 surveys from Dunn County citizens at town events; emailed
1,746 surveys to UW-Stout students and received 205 in return (12%
response rate); emailed 500 surveys to UW-Stout faculty and received 165
in return (33% response rate).
Analysis of what motivates people to install a buffer strip:
Variable
Knowledge of
ordinance
Concerns about water
quality
Logit Coefficients
Probit Coefficients
Log Odds Ratios
3.19*
1.82*
24.35*
9.92**
5.70**
20312.69**
Concerns about using
backyard space
-6.47**
Extent of backyard use
.93*
.54*
2.54*
.42
.25*
1.52
Money spent on
backyard
Percent of neighbors
who have buffer strips
Feel causes of pollution
within their control
R2 values
*p-value<.1 **p-value<.05
-3.67**
.0016**
2.04*
1.16*
7.67*
-2.07*
-1.22*
.13*
.7124
.7154
.7124
o From buffer strips along all the perennial streams and lakes in the
Dunn County portion of the Red Cedar Watershed
.65 lbs P
1,669 acres x
x 80% buffer efficacy=867.9 lbs P
acre
500 lbs algae
867.9 lbs x
=433,940 lbs algae
1 lb P
Self-reported buffer strip
implementation
Report having at least a
small buffer strip
35'+
3%
9%
13'-24'
0%
20% 40% 60% 80% 100%
*Based on survey data
41%
67%
Would
boat more
Would
use trails
more
13%
1'-12'
11%
Would
swim more
35%
24'-34'
Report not having a buffer
strip
72%
Percent homes with buffer strips on
Tainter by size
86%
Report planning to install a
buffer strip
What would people use the lake for if it
were cleaner?
How many people from Menomonie
travel to other lakes and why:
32%
None
11%
0%
10%
20%
30%
40%
*Based on Dunn County Land and Water Division data
69%
What resources do people need to put in buffers:
o
o
o
o
15%
25% would take advantage of educational resources
31% would take advantage of cost-sharing programs
37% would take advantage of landscape planning and advice
20% would take advantage of volunteer labor
31%
The people who would utilize educational resources and advice are often different
from those who would take advantage of cost sharing resources and volunteer labor.
3%
Willingness to volunteer:
Asked UW Stout students and faculty, and
Menomonie citizens whether they would be
willing to volunteer time to cleaning up the lake
17%
38%
58,313 total hours
20%
Willingness to fund:
Asked students, faculty, and citizens
whether they would be willing support
.1% sales tax to fund lake clean up
Not interested
1 afternoon
2 afternoons
Once a month
Once a week
22%
13%
85%
87%
No
Yes
Because other lake cleaner
Other reasons
Conclusion:
Regulations requiring shore line homeowners to install riparian
buffers make a small, but important contribution to efforts to
control phosphorus runoff. These zoning laws are somewhat
unique in that they apply to both residential and farmland, and
that in this way they help involve all parties.
Results show that many people already have the beginnings of
buffer strips and are willing to contribute. It seems that education
on water quality issues and help in understanding the ordinance is
key to achieving full adaptation of the legislation.
No
Yes
This work supported by National Science
Foundation SMA grant #135738