^t
Section 319
NDNPDINT SOURCE PROGRAM SOGGESS STORY
Coordinated Efforts Improve Water Quality in Beaver, Keller, Carver and
Battle Creek Lakes
A/ t h H' I H Nutrients in stormwater runoff resulted in the eutrophication and
VaterDOaieS imprOVea impairment of four |akes in Minnesota's Ramsey-Washington
Metro Watershed District (RWMWD). As a result, the Minnesota Pollution Control Agency (MPCA)
added the lakes to its Clean Water Act (CWA) section 303(d) list of impaired waters — Beaver, Keller
and Battle Creek lakes in 2002 and Carver Lake in 2008 — for failure to attain their aquatic recreation
designated uses. Implementing best management practices (BMPs) throughout the watershed
decreased stormwater runoff and improved water quality in the four lakes, allowing Minnesota to
remove them from its list of impaired waters in 2014.
Problem
The RWMWD is in the eastern Twin Cities Metro
Area in Minnesota (Figure 1). The majority of the
watershed is developed, with industrial, commercial
and residential land uses present. The watershed
district contains 12 cities, 18 lakes, five streams
and numerous wetlands. The Beaver, Carver, Keller
and Battle Creek lakes together drain more than 12
square miles of land within this watershed district.
All four lakes are regularly used for recreational
activities such as canoeing and fishing.
Minnesota water quality standards for aquatic life
and recreation for shallow lakes in the summertime
(June-September) require that (1) the average
total phosphorus (TP) concentrations are equal
to or less than (<) 60 micrograms per liter (/jg/L),
(2) chlorophyll-a (chl-a) concentrations are < 20/jg/L,
and (3) Secchi disc (SD) transparency is at least
1.0 meter (3.3 feet). For deep lakes, the standards
are more stringent, requiring that the summertime
average TP concentrations are < 40/jg/L, chl-a
concentration are < 14/jg/L, and SD transparency is
at least 1.4 meters (4.6 feet).
Data collected about every other week during the
growing season beginning in the 1970s (in Beaver,
Keller and Battle Creek lakes) and 1980s (in Carver
Lake) indicated that the lakes were not meeting
these standards. Battle Creek Lake exceeded
standards for TP, while Beaver, Carver, and Keller
lakes failed to meet standards for TP, chl-a and SD
from the late 1970s through the early 2000s. Based
on these data, Beaver, Keller and Battle Creek lakes
- • I, -
""--'
•"•-
_^«"
Data sources include Minnesota's CIS layer of assessed lakes, 100.51 2 3
USfiS Topo basemap, and a U.S. Census Bureau national state map.
Figure 1. The four restored lakes (Beaver, Carver, Keller and
Battle Creek lakes) are on the eastern side of St. Paul in
southeastern Minnesota's Twin Cities Metro Area.
(shallow lakes) were listed as impaired for failing
to attain their aquatic recreation designated uses
in 2002 and Carver Lake (a deep lake) was listed in
2008. Carver Lake was listed in 2008 rather than
2002 because consistent summer TP, SD and chl-a
water quality data were not available.
-------
Project Highlights
Numerous lake management
plans were implemented which
directed and focused the
restoration efforts for these
lakes. These plans culminated
in a 2007 RWMWD Watershed
Management Plan. Specific plan
elements included implement-
ing BMPs, stricter stormwater
treatment standards, and the
Volume Reduction Strategy that
the RWMWD adopted in 2006
(Table 1).
Table 1. A Timeline of Practices and Policies that Improved Water Quality
in the Four Lakes
Results
Project efforts helped
decrease phosphorus loading
to these lakes, which has led
to improved water clarity and
decreased chl-a concentrations. Recent monitor-
ing data indicate that water quality has significantly
improved in the four lakes (Figure 2). Due to year-
to-year variation in the lakes, the 10-year averages
(June-September) of TP, chl-a and SD were used
to analyze recent water quality trends. This analysis
revealed that Beaver Lake has consistently met the
state's eutrophication standards since 2006, Keller
Lake and Carver Lake have been meeting state stan-
dards since 2007, and Battle Creek Lake has metTP
standards since 2010. As a result, all four lakes were
removed from the impaired waters list in 2014.
Project (Date)
Tanners Lake Water Quality
Improvement Project (1997-1998)
Tamarack Water Quality Treatment
System Project (1999-2000)
Valley Creek Road Stormwater
Treatment Project (2002-2003)
Apostolic Bible Institute Water
Quality Pond Project (2002-2004)
Carver Lake Porous Pavement
Project (2005-2006)
Stormwater Volume Reduction
standard (2006)
BMP Incentive Program
(2006-2014)
Keller Lake Shoreline Restoration
Project (2010-2011)
Hwy. 36/61 Interchange Water
Quality Improvement Project
(2012-2013)
Project Description
Installed wetland enhancements, an extended detention system, a
sand filter system and an alum treatment facility for the Tanners Lake
watershed (discharges into Battle Creek Lake).
Installed two treatment ponds to treat stormwater runoff entering the
Tamarack Swamp wetland area (drains to Battle Creek Lake).
Installed infiltration and filtration treatment cells to treat roadway and
neighborhood stormwater runoff (discharges into Battle Creek Lake).
Installed approximately 660 feet of storm sewer and manhole/catch
basin units, one diversion structure, a water quality treatment pond and
a pond outlet structure to treat stormwater entering Battle Creek Lake.
Retrofitted two city cul-de-sacs with porous pavers to infiltrate
stormwater runoff.
A standard requiring that construction projects greater than 1.0 acre
retain 90% of stormwater runoff from impervious surfaces.
42 native habitat restoration projects, 5 filter strips/swales, 40 rain
gardens, 1 filtration basin, 4 infiltration basins/trenches, 7 porous pave-
ment projects, 3 green roofs, 1 wet pond and 8 cisterns/rain barrels.
Restored approximately 2,000 feet of shoreline using techniques such
as rip rap gabions and native vegetation.
Retrofitted an existing interchange to incorporate an enhanced sand
filter and constructed wetlands for stormwater treatment discharging to
Keller Lake.
Partners and Funding
Lake restoration efforts were supported by many
partners and funding sources. Specific part-
ners included the RWMWD, MPCA, Minnesota
Board of Water and Soil Resources (BWSR),
Minnesota Department of Natural Resources
(DNR), Metropolitan Council, city of Woodbury,
Ramsey County, city of Maplewood, Capitol Region
Watershed District, city of Oakdale, Apostolic
Bible Institute, Fortis Insurance and the Minnesota
Department of Transportation.
Nonpoint source project funding included
$2.1 million of Capital Improvement Funds pro-
vided from 1987-2013, $1.9 million in MPCA
Keller Lake Water Quality (1999-2013)
140-
120-
100-
80-
I Total Phosphorus
I Chlorophyll-o • Secchi Depth
Figure 2. Decrease in total phosphorus (TP), chlorophyll-a (Chl-a)
and Secchi depth (SD) concentrations (mean June-September)
for Keller Lake from 1999-2013. The other three lakes show
similar trends in these parameters.
state revolving fund loans, $100,000 each from
the city of Woodbury and BWSR, $69,000 from
the Metropolitan Council and $70,000 from DNR.
RWMWD served as the lead on these projects and
the project manager was funded using CWA section
319 match funds.
UJ
(9
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001J
January 2015
For additional information contact:
Tina Carstens, Ramsey-Washington Metro Watershed District
tina@rwmwd.org • 651-792-7960
Brooke Asleson, Minnesota Pollution Control Agency
brooke.asleson@state.mn.us • 651-757-2205
------- |