Water Day 2005
Tuesday, March 22, 2005 is World Water Day.
marks the start of the Water for Life Decade, 2005--2015,
effort to reduce by 50% the proportion of persons without
sustainable access to safe drinking water and basic sanitation.
for Disease Control is
doing. (new window)
more from the World
Health Organization. (new
have updated the outdoor
safety pages on our sister website:
to do if you fall through the ice.
Learn how to escape from a rip current.
More tips and links...
Some new links from the
latest MN Lakes Association e-newsletter:
Think Bottled Water Is Better
Bottled water has become big business, catering to people's concerns
about tap water. Is bottled water really cleaner? The Minnesota Department
of Health has a new fact sheet that discusses the relative safety
of bottled versus tap water. Check it out here: www.health.state.mn.us/divs/eh/water/com/fs/bottledwater.html
The Hottest New Landscaping Trend---Rain Gardens
Rain gardens are the hottest new landscaping trend. These do-it-yourself
flower patches in your yard can clean up gritty storm water
our streams much cleaner. Click here (http://clean-water.uwex.edu/pubs/raingarden/)
to learn how to create your own rain garden using native wildflowers
and grasses to create your own little storm water retention
area in your yard. The article Gardens For a Rainy Day in the
June DNR Volunteer Magazine also provides practical tips on
planting a rain garden (http://www.dnr.state.mn.us/volunteer/mayjun04/raingardens.html)
the Green Works video entitled "The
Lake Access Project".
to Water on the
Web (WOW) National Advisory Team member Earl Byron in California
for bringing the following to our attention:
Posted on Sun,
Mar. 14, 2004 in the San
Jose Mercury (California) News from the Associated Press.
falls victim to Internet hoax, considers banning items made with
water. This article went on to report that well meaning officials
in the City of Aliso Viejo, California were considering banning
foam cups after they learned that the chemical dihydrogen monoxide
was used in their production. Although there may be other reasons
to consider such a measure, and although the chemical is odorless
and tasteless and can be deadly if accidentally inhaled, it is also
essential to life on earth and the major reason for the current
explorations of Mars. They should have been subscribing to the WOW
Medicine Lake unit is
up and running.
Association of Medicine Lake
Area Citizens (AMLAC) now has a website.
A mystery has been solved.
The mysterious hole in the ice that showed up this past winter in
North Long Lake near Brainerd was formed by upwelling groundwater.
Check out the "Lake
Detective" for an explanation.
about other Minnesota water bodies?
Check out the Duluth Streams web site. This project focuses
on urban streams and stormwater issues in Duluth, MN. As in LakeAccess,
Duluth Streams has a real-time
data emphasis, with 3 stream monitoring stations deployed in three
water suspected in 'black holes' on Long Lake, Forest Lake
Read about mysterious warm spots in Minnesota lakes in this January
22, 2003 article
printed in the Minneapolis Star Tribune.
Appeals Court Upholds Runoff Rule
DC, January 15, 2003 (ENS) - Small cities, counties and developers
must protect waterways from stormwater pollution, a federal appeals
court ruled Tuesday. The court found that the U.S. Environmental Protection
Agency's stormwater program is constitutional, rejecting claims that
the agency exceeded its authority by requiring cities and developers
to decontaminate stormwater before discharging it into rivers, lakes
and coastal waters.
read the full article at the Environmental
Minnesota Lake Association's (MLA) October 24, 2002 monthly Lakes
Phosphorus Lawn Fertilizer Law is outlined in a new fact sheet
from the Minnesota Office of Environmental Assistance (OEA). Starting
this year, it is required by Minnesota state law to clean up any
fertilizer spread or spilled on paved surfaces. Starting in 2004,
the laws requires the use of 0% phosphate lawn fertilizer in the
seven county metro and 3 percent phosphate or less lawn fertilizer
in Greater Minnesota (with exceptions for new lawns or when a soil
test shows a need.)
View the fact sheet at http://www.moea.state.mn.us/campaign/download/phosphorus.pdf.
Quantities of the fact sheet are available at no cost from the Minnesota
Office of Environmental Assistance;
call 800-877-6300 (Metro 651-215-0232), or e-mail firstname.lastname@example.org
RUSS units are off their respective lakes.
Public debate over the use and abuse of Personal Watercraft ( PWC's,
Jetskis, Seadoos, and others) is a passionately argued water resource
issue among water recreationists -not only in the Upper Midwest, but
throughout the world. The conflict has some similarities to the debate
about the use and regulation of ATV's and snowmobiles in that it may
be oversimplified as simply another case of environmentalists trying
to lock up a natural resource from recreationists. Recently, the American
Canoe Association (ACA) published Hostile Waters: The Impacts
of personal watercraft use on waterway recreation [923 KB pdf file]. This study
reported that although PWC's comprised less than 10 percent of all
vessels, they were involved in 55 % of all collisions in U.S. waters.
The conclusions were based on the last 5 years of available accident
data (1996-2000) collected by the United States Coast Guard (USCG)
and state boating agencies and their statistics were verified by the
USCG. To provide a counterpoint perspective, we have listed relevant
websites in our Boaters section of LakeAccess.
We have also reproduced an apparent Personal Watercraft Industry Association
(PWIA) eight page response to Hostile Waters in this same section.
fun site to learn about water conservation.
US Water News featured website for the month of September is http://www.H2ouse.org
. This website was developed cooperatively with the California Urban
Water Conservation Council. It is a handy place for homeowners to
find out about water efficient equipment and practices for the home.
Water conservation not only saves water but conserves the energy used
for pumping and treating it as drinking water and as wastewater both
in your home and via public agencies. In rural situations, it saves
you well and septic system costs. It can also be an important factor
in reducing surface and groundwater water quality degradation.
has been one of the top
10 wettest summers in the Twin Cities.
Halsteds Bay unit is going to be off-line for the next couple of weeks
the Medicine Lake and Halsteds Bay units are up and running!
to start preparing to celebrate the 30th Anniversary of the enactment
of the Clean Water Act on October 18, 2002.
Learn more about
the Clean Water Act or register to participate in National Water
Monitoring Day by visiting www.yearofcleanwater.org.
Need an expert
to answer your question?
You can always ask one of us (but we're the first to admit we don't
know everything) but there are lots of experts out there. Try the
signed the phosphorous-free fertilizer bill last week.
(from the MINNESOTA LAKES ASSOCIATION LEGISLATIVE REPORT: 4/29/2002)
law restricts the use of lawn fertilizer containing phosphorus to
zero (0) percent in the seven-county metropolitan area and three
(3) percent throughout the rest of the state unless a soil test
is done and proves that phosphorus is needed. A soil test, using
a mail-in kit, would be good for three years. Golf courses would
be exempt from the new law, as would new lawns.
Local units of government in the Greater Minnesota 80 counties could
adopt a zero percent standard throughout their county, city, or
township through an ordinance until January 2004, when the new law
goes into effect. If they pass an ordinance more restrictive than
three percent they would have to inform the State Department of
Agriculture of their plans. Local outstate governments would also
have until August 1, 2002 to pass ordinances that would restrict
the sale of phosphorus lawn fertilizer, as well as, the use of the
Enforcement of the new law would be done locally. The new law also
includes language on development of consumer education information
atthe retail level. MLA will be involved in this process.
The ice is
The ice went
out on Lake Independence yesterday, and it went out on Lake Minnetonka
today (the average ice out date for Lake Minnetonka is 4/15).
Fertilizer Phosphorus Bill Passed
No greater than
3% P2O5 fertilizer within all areas in Minnesota, zero in the metro
Lawn Fertilizer Phosphorus Bill in the House
It is anticipated
that the Lawn Fertilizer Phosphorus Bill, SF 1555, will be voted
on Tuesday, April 2nd, in the House. Rep. Leppik is introducing
the bill. The MN Chamber of Commerce has come out against the bill,
and the vote may
It is anticipated
that an amendment will be offered by Rep. Dorman to allow use of
3% P2O5 lawn fertilizer state-wide and preempt local ordinances
that are more restrictive (e.g., 0% P2O5).
If the House
version passes with the 3% P2O5 statewide amendment, then two possible
outcomes are anticipated from conference committee (differences
between House and Senate versions of a bill are ironed out in conference
1. No compromise
can be struck and the bill dies, or,
2. A compromise
will be struck which removes the 3% P2O5 statewide
Note the liberal
use of the word "anticipated"! Nothing is for sure in
the law making process.
65 - 1 on SF 1555, Lawn Fertilizer Phosphorus Bill
SF 1555, the Lawn Fertilizer Phosphorus Bill, passed the Senate
3-8-02 on a final vote of 65 - 1. The one opposition vote was Senator
Mady Reiter, of Shoreview. The bill passed a "General Orders"
vote on 8-7-02 by 55 - 3.
The bill was
amended twice on the floor. One amendment allows local units of
government to continue to regulate "raw" manure handling
(i.e., not processed and bagged), something they need to do administer
The other amendment
allows enforcement of lawn fertilizer regulations to be carried
out by either local units of government or the Minnesota Department
HF 1524, the
House version of the bill, is expected to be voted on yet this session,
but it is not known when. There are slight differences between SF
1555 as passed and HF 1524 in its present form. These differences
will need to be rectified on the House floor, or in Conference Committee
if the two bills do not match in their final passage.
on HF 1524, or its author, Rep. Leppik, go to: http://www.house.leg.state.mn.us/
Both bills regulate
the use of lawn fertilizers containing phosphorus in order to reduce
phosphorus pollution of lakes and rivers.
of the bills are:
Use only 0% P2O5 lawn fertilizer in the seven county metro
area, unless the lawn is newly seeded or a soil test shows phosphorus
Use no higher than 3% P2O5 lawn fertilizer outside of the
seven county metro area, unless the lawn is newly seeded or a soil
test shows phosphorus need.
Local units of government outside of the seven county metro
area can opt to change their 3% P2O5 restriction to a 0% P2O5 restriction.
All fertilizer applied to impervious surfaces (driveways,
sidewalks, streets), needs to be cleaned up.
Bill passes House Committee
HF 1524, the
House bill regulating the use of phosphorus lawn fertilizer, passed
the House Committee on Local Government and Metropolitan Affairs
The bill now
goes for a vote on the House floor unless a chairperson of another
House committee requests a hearing. That does not seem likely, but
Leppik requested a "delete all" amendment to replace existing
HF 1524 language with new language she presented. She also requested
an additional amendment to the "delete all" language.
Both amendments were approved.
language to HF 1524 follows closely the language in SF 1555, Senator
Higgins' bill that made it through Senate committees last week.
BUT there are two main differences:
Preemption (authority the state can withhold from local government)
bill (SF 1555) takes authority for regulating phosphorus lawn fertilizer
USE away from local government, but allows local government to continue
regulating the SALE of phosphorus lawn fertilizer.
House bill (HF
1524) takes authority for regulating BOTH phosphorus lawn fertilizer
USE and SALE aw ay from local government, but allows local ordinances
regulating phosphorus lawn fertilizer SALE pa ssed by August 1,
2002, to stay in effect.
back to legislature
bill (HF 1555) requires the Commissioner of the Minnesota Department
of Agriculture to report back to the legislature by 1/1/2007 (five
years after the bill's enactment) as to the bill's effectiveness.
(SF 1524) makes no such provision.
Both the House and Senate bills are heading for floor votes. They
are very similar, but do differ. Either the differences will be
patched up with floor amendments, or in conference committee if
the House and Senate approve bills with different language. Both
bills set January 1, 2004 as their effective date.
Go to http://www.senate.leg.state.mn.us/
for information on SF 1555, Senator Higgins, and the Senate schedule.
Go to http://www.house.leg.state.mn.us/
for information on HF 1524, Representative Leppik, and the House
Lawn Fertilizer Bill, clears Senate Ag Committee with amendments
The first engrossment
of SF 1555, the bill that restricts use of phosphorus lawn fertilizer,
passed the Senate Agriculture Committee on 2/22/02 with these amendments
that, besides the special provisions made in this bill for phosphorus
lawn fertilizers, local units of government cannot regulate agricultural
2. Only speciality
fertilizer (bagged lawn and garden fertilizer) will be required
to assure their reported nutrient content is within given minimum
and maximum allowances. Bulk mixed agricultural fertilizers will
be exempt from staying within maximum allowances since it is hard
to mix with accuracy using large equipment.
3. Organic fertilizer
will be held to the same phosphorus content standard as inorganic
fertilizer. Previously, up to a 2% P2O5 organic
fertilizer could be used in areas with a 0% P2O5
4. All lawn
fertilizer applied to impervious surfaces, whether it contains phosphorus
or not, needs to be cleaned up. Previously this clean up provision
was required of fertilizer containing phosp horus only.
The next stop for SF 1555 is the Senate floor for a vote.
It could have gone to the Senate State and Local Government Committee,
but Senator Vickerman, who chairs that committee and also sits on
the Senate Ag Committee, allowed that step to be by-passed providing
the bill's author, Senator Higgins, works out any outstanding concerns
before the bill goes to the Senate floor for a vote.
Now the bill
needs to be moved through the House side of the legislature.
Representative Leppik is sponsoring the bill as HF 1524, a bill
from last session that will likely be modified to match the current
First step for
HF 1524 is the House Local Government Affairs Committee. If it passes
that committee it likely will move the the House Agriculture Committee
and maybe also the House Environment Committee.
on SF 1555 and Senator Higgins go to: http://www.senate.leg.state.mn.us/
on HF 1524 and Representative Leppik go to: http://www.house.leg.state.mn.us/
on House Committee scheudules, go to: http://www.house.leg.state.mn.us/hinfo/wsched
regarding SF 1555, the Senate bill concerning regulation of phosphorus
Friday, February 22, 2002
Senate Agriculture, General Legislation & Veterans Affairs
Room 107 Capitol
instructions at http://www.leg.state.mn.us/leg/capitol.htm)
Let the members of the Senate Agriculture Committee hear from you
regarding the bill to allow local governments to pass more restrictive
options than 3 percent phosphorus fertilizer limits
The next stop
for SF 1555, the Senate bill concerning regulation of phosphorus
lawn fertilizer, is the Senate Agriculture committee. It must
pass through the committee by Friday, February 22 to "stay
alive" in the session.
To find out more about the current status of the bill, visit the
and Natural Resources Committee home page and search for SF
1555 in the Bill Information search section.
At today's meeting
of the Environment and Natural Resources Committee, Senator
Higgins moved a "delete all amendment" on SF 1555, the
Senate bill from last session concerning regulation of phosphorus
lawn fertilizer. The committee supported the motion, and in so doing
emptied the contents of the bill and replaced it with new language.
Then new bill language passed committee with a strong majority.
The provisions of the new SF 1555 are summarized on the February
14 Watertalk Up-date.
A new section
has been added describing the Lake
Access II Lawn Fertilization Study. It includes the study design
and recent results from the 2001 lawn runoff study, GIS maps, and
current and historical data on Medicine Lake. It will also soon
include stream data from Plymouth and Ridgedale Creeks including
new stream data visualization tools.
Action section has been expanded and now includes a Community
Both the Medicine
Lake and Halsteds Bay units have been removed for the winter. Biweekly
winter profiles will be taken as soon as the ice is safe.
Environmental Protection Subcommittee held a public hearing
on the issue of restricting the sale and use of phosphorus in fertilizer
used on turf at the State Capital. The speakers included city officials,
park managers, turf industry representatives, private citizens,
University of Minnesota faculty, and state agency personnel. The
mayor of Shorewood, Woody Love, started the hearing by voicing a
few main points that were subsequently repeated by the majority
of other meeting speakers. He emphasized that the proposed legislation
would be; relevant as approximately 80% of the lawns in the Twin
Cities metro do not require additional phosphorus inputs by lawn
fertilizer, a "restriction" on the use not a ban, and
only one part of the overall plan to reduce phosphorus inputs to
waterways. The turf industry representatives did not support the
legislation as they claim that phosphorus-free fertilizer may actually
be bad for the environment.
Senate Environmental Protection Subcommittee will hold a public
on the issue of restricting the sale and use of phosphorus in fertilizer
used on turf on Wednesday, November 14 in Room 15 of the
State Capitol at 1 PM. Please join us if you are interested in
Please contact Julie Rusk in my office if you would like to testify.
651-296-9246 or email: email@example.com. The
city of Minneapolis recently passed an ordinance restricting
the sale and use of phosphorus.
St. Paul is also considering such an action.
Halsteds Bay and Medicine Lake RUSS units are both up and running.
Medicine Lake unit is up and running. Halsteds Bay should be on-line
by the end of this week.
metro area lakes found to have Eurasian watermilfoil !
MN DNR press
For more information, contact Chip Welling, DNR Ecological Services,
Despite a cool, wet spring, the total number of Minnesota water
bodies infested with Eurasian watermilfoil grew by five in the first
months of this year's open water season. This brings the total number
of Minnesota lakes, wetlands and rivers known to be infested with
this harmful exotic plant to 126.
New and widespread infestations were found in Parley, Wasserman
and Eagle lakes in Carver County, and Sunset Lake in Washington
County. The presence of widespread milfoil indicates that the plant
became established in these lakes some number of years before it
was discovered, according to the Department of Natural Resources
(DNR) officials. A small infestation was found in Galpin Lake in
"While it's disheartening each time new infestations of milfoil
are reported, we believe that Minnesota has slowed the spread of
this exotic," said Chip Welling, DNR Eurasian watermilfoil coordinator.
According to Welling, the rate of spread is low due to the high
level of awareness among boaters about the need to always remove
all aquatic plants from their boats, motors and trailers before
The high level of awareness is attributed to efforts by watercraft
inspectors, local lakeshore associations, and others to inform users
of Minnesota lakes and rivers about what they can do to prevent
the spread of milfoil and other aquatic exotic species.
Though 119 Minnesota lakes now have milfoil, this represents only
1 percent of all the lakes in the state. "Users of Minnesota's lakes
and rivers need to continue to work to prevent the spread of milfoil
to the 99 percent of our lakes that do not have the exotic," said
Involvement in EPA Decisions - A National Dialogue via the Internet
Convened by the U.S. Environmental Protection Agency Hosted by Information
July 10 - July 20, 2001 You are invited to participate in an
online public discussion with EPA and panels of experts on improving
public involvement in EPA decision-making. Please join a broad cross-section
of individuals who will share their thoughts and ideas on this important
topic with each other and with the Agency.
Over the course of 10 days (including a Saturday), the participants
will discuss specific topics drawn from EPA's newly drafted Public
Involvement Policy. EPA is now seeking your thoughts and ideas on
how it should implement this policy. Because this will be a web-based
discussion, you can select the topics that interest you and participate
at your convenience.
A revolving panel of experts will discuss the main aspects of the
draft Public Involvement Policy with each other and with approximately
500 participants. Among the topics that we will discuss >are the following:
1) Identifying and involving the public, including those hardest to
reach; 2) Providing information to the public; 3) Creating effective
public involvement opportunities during rulemaking and permitting;
and 4) Encouraging collaborative processes.
The Dialogue is an excellent opportunity for citizens, representatives
of industry, environmental groups, small businesses, states, local
governments, tribes, and other groups to learn more about the draft
Policy and to share their thoughts and concerns with EPA. To learn
more about the Dialogue and to register to participate visit the Dialogue
Web site at: http://www.network-democracy.org/epa-pip For more information:
Send e-mail to Patricia Bonner at U.S. EPA: firstname.lastname@example.org.
or Information Renaissance: email@example.com or call 888.638.5323.
Medicine Lake unit has been deployed but we are having some technical
North American Secchi Dip-In 2001
Programs and Volunteers Needed!
Contribute to a Snapshot of North American Water Quality
June 30 - July 15, 2001
enroll your program at their Website
volunteers in your program will receive a
summary of the Dip-In 2000, whether or not they participated in
Watch : The Minnesota
Climatology Working Group has a web page showing ice-out dates
for a number of Minnesota lakes including Minnetonka.
development near Twin Cities lakes threaten the region's excellent
fishing? Find out by going to the MN DNR website to an article called
road to poor fishing".
Check out the
Water Quality Index Map for Minnesota (smaller
version) The map shows the trophic
state index (TSI) and secchi
depth for lakes across the state. You can find your lake by
going to the LakeBrowser.
the EPA EMPACT Technology Transfer Manual
You'll need Adobe Acrobat and some
time, it takes a bit to download.
Lake Access and Water-on-the-Web
have won the 2000 Technical Excellence Award for public education
and research, from the North American Lake Management Society, in
recognition of extending effective and creative education in lake
restoration, protection, and management. Rich Axler and Chris Owen
were in Miami to receive the award
The Russ units
have been removed from the lakes and we're waiting for ice-on.
||News Flash.....James Johnson of Hennepin
Parks comes face to face with furry RUSS saboteur.
Today as James
searched for a reason why the Halsteds RUSS unit stopped working he
noticed chew marks along the profiler cable. As he looked into the
middle of the RUSS buoys he came face to face with the culprit. A
muskrat has made the unit his home and seems to like chewing on cables.
More to come.....
attends EPA Environmental Monitoring Conference Boston, MA
(Click the Cod
to see Lake Access in action)
Lake Independence RUSS (our oldest unit) is in the shop for repairs.
We'll let you know when it gets back on-line.
West Upper unit needs a chance to get back to full battery power so
we will cut back on the number of profiles from four to two per day
at least for a few days.
Access staff conducted a survey of west metro landowners last fall.
Please check out the results.
Access attends the Carp Festival!
Lake Access and RUSS were featured at the Mississippi River Carp
Festival held on Saturday, June 17th. Kids and adults played with
a model RUSS unit and talked with Lake Access staff members. The
Lake Access refrigerator magnets were a big hit, contact
us if you'd like one!
to decide who's the carp and who's the crab (crayfish really)
Access Website is undergoing a major renovation and is changing daily.
Be sure to check often for new features.
units deployed on to Lakes Minnetonka and Independence for the 2000
open water season.
Minnetonka. This is the second earliest ice-off in 123 years! The
earliest ice-out was March 11, 1878. Independence ice was gone 3/11/00.
can turbidity tell you?
Look how clear
the water is under the ice by running either the color
mapper or examining the colorized DxT plotter from the Data
Visualization Toolkit. The turbidity is extremely low and then
gradually increases after ice-out. We think that the discrete blobs
of turbidity (spikes in the Profile Plotter plots and green smudges
in the Color Mapper and DxT plots) may be due to resuspended sediment
induced by wind mixing of nearshore and perhaps bottom sediments
before the lake stratifies. Later on in the spring and summer, algal
growth provides a more important contribution to turbidity.
Our RUSS data
set and Hennepin Park's water chemistry data from last summer showed
that sudden mixing events at Halsteds Bay could have dramatic effects
on water quality. Severe thunderstorms with high winds and tornado
warnings ripped through the Twin Cities area in August and September
1999, leading to sudden mixing and re-aeration events at the Halsteds
Bay RUSS site in Lake Minnetonka. The event ultimately had profound
water quality consequences by disrupting stable thermal stratification
and introducing high nutrient/low oxygen bottom water into the upper
sunlit layer of the bay resulting in an obnoxious algae bloom some
days later. This, in turn, led to further changes in the depth and
time patterns of dissolved oxygen, pH and turbidity. The nearby
West Upper Lake water column responded very differently to the wind
event and produced much smaller, if any, serious water quality effects.
In fact, there
are economically important land and lake management implications
that derive from these data in terms of how to most efficiently
restore the degraded water quality in Halsteds Bay. Restorative
management decisions involving millions of dollars of tax monies
are currently being discussed for Halsteds Bay. Such storm-related
events were suspected, but prior to our RUSS data, were not documented
due to their transient nature and the danger of manual sampling
during severe weather. In fact, several of these events were observed
in August 1999 (see figures below).
In each case,
temperature profiles didn't tell us the state of mixing of the bay
since variations from surface to bottom were only about 1oC. However,
dissolved oxygen (and to a lesser extent pH and EC25) clearly indicated
that the lower half (~5 m) of the water column dramatically changed
from extreme anoxia to >75% saturation and then back again to anoxia
over intervals of ~ 24 hours in mid and late August/early September.
During the initial mixing, the influx of anoxic water to the "epilimnion"
actually decreased the level of DO to ~5 mg/L, which could potentially
impact fish communities. In addition, water samples collected on
August 25, about 10 days after the first mixing event, showed that
about 3200 kg (over 7000 lbs of P) was suddenly injected into the
upper sunlit euphotic zone. This represented an areal phosphorus
load of about 3x the annual load estimated to enter Halsteds Bay
from Six Mile Creek, its major tributary. The sudden input of P
appears to have then caused an increase in algal growth, seen as
a chlorophyll increase over the same manual monitoring interval
(Barten and Vlach 1999, L. Minnetonka Annual Monitoring Report).
Recall that 7000 lbs of P can potentially lead to over 3,500,000
lbs of algae !
These new data,
that would likely not have been acquired without remote sensing,
suggest that water quality in nutrient enriched lakes of intermediate
depth (perhaps 5-10 meters) may often be controlled by weather events.
The data also indicate that watershed BMPs, alone, may not be successful
in improving the water quality of these bays without concurrently
reducing internal P-loading. Of course this does not diminish the
importance of preventing increases in external P-loading from old
and new developments over the long-term. However, it does offer
important insights into the cost-effective management of water quality
for 6 bays on the west and north end of the lake that have shown
significant downward trends in water quality over the past 5 years.
maps of mid-late summer depth profiles of temperature and dissolved
oxygen for Halsteds Bay and West Upper Lake regions of Lake Minnetonka.
temperature ranges from warm (red) to cold (blue) and dissolved oxygen
ranges from high (green) to low (brown) to anoxia (black).