BLACKWATER LAKE
Management Plan
HEALTHY LAKES PROGRAM
THE INITIATIVE FOUNDATION
FINAL
September 29, 2011
Prepared by: Healthy Lakes Initiative Committee
Blackwater Lake
I. INTRODUCTION
In June 2011 the Blackwater Lake Association was invited to participate in the Initiative Foundation’s Healthy Lakes and Rivers Partnership program along with six other Lake Associations in Cass County. Under the coordination of John Ringle (Cass County Water Planner and Director of Environmental Services), representatives attended a two day session of training on strategic planning, communication, and nonprofit group leadership.
Representatives of many state and local agencies, as well as nonprofit organizations, also attended the training sessions in order to offer their assistance to each group in developing a strategic Lake Management Plan. The Blackwater Lake Association was represented at the Healthy Lakes & Rivers training sessions by: Bob Seemann, Lloyd Thielmann, Jim Eller and Linda Burns. After the sessions we were joined by Carolyn Dindorf and Barb Laughlin who will help serve on the committee.
Following the training sessions, each Lake Association held an inclusive community planning/visioning session designed to identify key community concerns, assets, opportunities, and priorities. The Blackwater Lake Association held this planning session on July 30, 2011, facilitated by John Sumption. There were 15 people in attendance, with about 20 percent of the participants describing themselves as year round residents. Details of the public input received at this session are provided within this plan.
This document is intended to create a record of historic and existing conditions and influences on Blackwater Lake, and to identify the goals of the Blackwater Lake community. Ultimately, it is meant to also help prioritize goals and to guide citizen action and engagement in the priority action areas. Clearly, state agencies and local units of government also have a vital role and responsibility in managing surface waters and other natural resources, but above all else, this Lake Management Plan is intended to be an assessment of what we, as citizens, can influence, what our desired outcomes are, and how we will participate in shaping our own destiny.
This Lake Management Plan is also intended to be a “living document”. As new or better information becomes available and as we accomplish our goals or discover that alternative strategies are needed, it is our intent to update this plan in the hope that it may continue to serve as a useful guide to future leaders.
In discussing lake management issues, it is impossible to avoid all scientific or technical terms. We have tried to express our goals, measures of success, and other themes as simply and clearly as possible, but have included a glossary of common limnological terms at the end of the plan to assist the reader. (Limnology is the scientific study of lake conditions and behavior.)
Finally, we would like to thank the founders of the Healthy Lakes & Rivers Partnership program for Cass County, including The McKnight Foundation, The Laura Jane Musser Trust, U.S. Environmental various staff from the Initiative Foundation, and over thirty generous individuals, Protection Agency, McDowall Company, the Cass County Water Plan, Lake Hubert Conservation Association, Portage-Crooked Lakes Association, and the Sibley Lake Association of Crow Wing County, the Ann Lake Sportsmen’s Club of Kennebec County,
Blackwater Lake is a 722-acre lake with a maximum depth of 67 feet. It is located 7 miles SW of Longville, MN, the nearest town. Blackwater Lake is DNR Lake ID number: 11-0274, in Cass County. The lake is in the Northern Lakes and Forest eco-region and in the Upper Mississippi river basin. Locally, Blackwater Lake is part of the Leech Lake Watershed.
The Minnesota Department of Natural Resources has classified Minnesota’s lakes into 43 different lake classes based on physical, chemical, and other characteristics. Blackwater Lake is in lake class 25. Approximately 47% of the lake is 15 feet or less in depth. There is a DNR public access on the north end of the lake off of County Road 11. The bottom content is: 90% sand, 5% muck, and 5% clay. The ordinary high water level is1326.5 feet, with a water clarity (secchi disk reading) averaging 12.2 feet. The highest water elevation recorded was 1327.33 feet on May8, 1999 and the lowest on record is 1324.4 on Feb28, 1935. The average weed line is 12 to 15 feet, as measured from the shoreline.
In 1989 the Minnesota Pollution Control Agency (MPCA) conducted a Lake Assessment Program of the area and noted that the average annual precipitation for our area ranges from 26-28 inches. The evaporation ranges are 30-32 inches. Annual average runoff is approximately 6 inches.
Spring tie ice-out averages around April 20th with the earliest we know of on April 2nd and the latest we know of on May 2nd. The fall freeze-up averages around the last few weeks of Nov to the first week of Dec. .
According to a 1988 MPCA Lake assessment Report the lakes in this area are ice block basins formed in the outwash deposits of the late Wisconsin glaciations. The topography northwest of Blackwater Lake is characterized as pitted to hilly moraine in contract to the flatter sandy outwash where our lake was formed. Soils in the watershed are classified as Nebish-Rockwood. The light colored well-drained soils have developed from loam (Nebish) and sandy loam (Rockwood) soil types. Some organic and poorly drained mineral soils occur in the depressions.
A. Blackwater Lake Association
The Blackwater Lake Association was formed in 1996. Since its inception the Blackwater Lake Association has encouraged good land use practices, promoted recreational fishing within the law and natural limits of the lake and worked to educate both members and non-members about the importance of lake stewardship. Stewardship has consisted of regular newsletters and meetings and participation in our many programs to keep our water quality and quantity at the desired level and condition it has been.
Blackwater Association has approximately 100 paid members. Information is sent to all 200 plus land owners and other interested groups such as Cass County officials, local elected officials and state agency staff. We do this by the use of our BLURB which is a publication also written by volunteers. It is sent out 2-3 times a year.
The association is run under bylaws with elected officers and board members with voting on issues at the annual meetings. A copy of the By-Laws of the Association is attached in the Appendix.
In addition to advocacy role, the Blackwater Lake Association continues to work and develop conservation projects. One such project was completed and filed in 2001 preserving approximately 47 acres with a shoreline of 2,797 feet. It is now in conservation management with the Cass County and the State of Minnesota. This parcel of land is located at the north/northwest end of the lake and is to the east of the outlet into Woman Lake.
Other projects include continuing attempts to control our beaver population to keep the water level and clarity at desired levels and our latest major undertaking of the wandering bog removal. We have hired and continue to hire a beaver trapper to control their population and keep the outlet into Woman Lake open and flowing. We were also instrumental in the replacement of the culvert under County #11 to allow the flow of water through our lake. The bog removal has been and is ongoing. It will take about 5 years by the time it is completed. Members of the association with saws and pontoons volunteer their time and energy to cut and push pieces of the bog to the public access. We hire a local contractor to remove these pieces and haul them away. This has been done with volunteer time and great monetary donations from our membership.
We are in the process of scheduling an Aquatic Plant Survey (2012) to follow up on the one done in 2005. We also pay for and encourage septic system testing for all property owners on the lake. This septic testing is very important to find and stop potential lake water contamination.
We have a committee that monitors our new property owners to change addresses on our mailing roster and to inform them of the great lake association that we have. The new owners are given a packet with DNR information, a copy of our newsletter and an application to join our association. This new member committee does a great job of keeping track of the endless change that take place in our population.
II. VISION STATEMENT
Blackwater Lake’s mission is to preserve the resources for future generations by providing necessary action and education on an ongoing forum.
This is the purpose of the following management plan.
III. HISTORY
The American Indians knew Blackwater Lake in the early days. Pottery shards were found on the shore area of the north end of the lake.
With the logging era came the stagecoach trail along the east side of the lake. This was abandoned when highway 84 was constructed in the early 1920’s. At that time it was called the Longville Road. Pontoria was the early post office for our area. You could purchase ice and groceries as well as play slot machines.
In the early 1900’s the tourist economy began with the building of fishing camps. In approximately 1936, a group of men from the telephone company, known as the “telephone gang”, began to use Blackwater Lake. One such person, Richard Ebner, bought property on the northwest shore, which had a small settlers’ cabin. He later added to the cabin. The cabin still stands. In those days fishing was very good. It took the fishermen hours to row their boats around the lake. Trolling was, of course done, via oars. By the 1940’s there were several resorts on Blackwater and by the 1950’s there were five resorts. During this time there were about eight private cabins or homes. With the 1960’s came changes with more construction of cabins and homes. At this point in time only two resorts were left and approximately 130 cabins or homes.
To maintain or improve the lake and fishing quality, a Blackwater Sportsman’s Club was formed in the late 1950’s or early 1960’s. At the beginning this was mostly supported by the resorts, but later included private cabins and homes. Some of the activities recommended by the club were specific hours for water skiing and the posting of fish spawning areas early in the fishing season. The group met during the summer months. Lack of interest was the downfall of the club in the 1970’s
Due to the number of people who were moving to the lake in the 1990’s, a new organization was formed in 1996. This organization was and is still called the Blackwater Lake Association. Care and concern for the future of the lake are still high priorities of this organization.
COPY OF THE LAKE MAPPING
IV. Schedule – Dealing in the areas of concentration taken from our lake management focus areas.
A. Project Focus:
1. Water Quality – To continue to summarize water quality monitoring programs and special surveys coordinating with Cass County and other agencies in an ongoing format. We will continue secchi disk readings to monitor water clarity. We will continue to trap and control beaver populations to control water level, run off and bog movements. We will remove the remaining section of the wandering bog. We will continue to pay for the septic system testing of lake properties in order to detect failing systems and recommend repairs. We also participate in water testing for chemicals which is done by our volunteers thru ACCL and is done by RMB testing Labs
2. Fisheries Management Plan- To maximize efforts which
Improve the quality of sport and recreational fishing in
Blackwater Lake, we will work to protect and maintain future fish population and habitat. To accomplish this goal we will be working with the DNR whenever and wherever possible. The association as a group voted not to support the catch and release plan of the DNR but it passed and we now support it. We also closely watch the amount and actual stocking of walleye into our lake.
3. Aquatic Vegetation- We will continue to improve existing aquatic plant management strategies to protect natural habitats and allow quality water surface use. We plan to have an aquatic vegetation study follow up done in 2012 if possible, to compare results with the survey done in 2005. On July 18, 2005 and Sept6, 2005 an AVAS vegetation survey was conducted by Professional Lake Management. The survey found that Blackwater Lake is moderately diverse with 9 species of submersed plants, 1 species of floating leaved plants, 3 species of emergent plants and 1 species of algae. They are all native North American species and benefit the lake in their various functions. At this time we had no invasive species that we know of and we are striving to keep it that way. We feel that we need to be as ready as we can possible be for the problem of invasive species.
4. Wildlife- We will communicate with the lake property owners to keep their shoreline as close to natural as is possible to support our wildlife as much as is possible.
5. Exotic Species- We will be doing another aquatic plant survey to compare with past results and make plans to avoid AIS. We will be working on signage for our public access and area roads to stop the spread of these invasive species. We are currently studying ways of patrolling this problem and possible solutions such as cleaning boats, etc.
6. Land use and zoning- We have members of our association and board of directors on the local township boards and are very concerned with the local building and zoning laws. In the past we have worked with the Leech Lake Watershed District to secure 47 acres of land with approximately 2797 feet of lake shore. This parcel is on the north shore by the outlet from our lake to Woman Lake. We have a committee formed and checking into the same type of possibility on Little Blackwater which is a small bay in our lake. The area in question is the east shore of this small bay.
7. Managing water surface conflicts- We want to encourage the recreational use of the surfaces for the many different sporting and enjoyment uses that are present. We encourage our members to contact the sheriff department or the DNR if any problems arise.
8. Public access- The DNR runs a very nice public access at the northeast corner of the lake. They remove and install the dock on a very nice concrete access. We have a bulletin board on the site and plan to use it for signs to control aquatic hitch hikers and are in the process of acquiring signage to inform the boating public of possible problems and their solutions.
The Blackwater Lake Healthy Lakes Visioning Meeting was held on July30, 2011 was attended by 15 property owners and we discussed the actions that we should focus on. The association sent out a notice to all property owners and concerned people (225) to inform them of this meeting. We were led by John Sumption as our facilitator and he helped us identify our issues. The two largest concerns were water quality and aquatic invasive species. Our focus will be on these two areas and we will direct our effort and grant monies in these directions.
A copy of the final Lake Management Plan will be provided to all lake property owners and other interested groups or individuals that request it at the July 2012 annual meeting.
Information regarding the identified goals and plans discussed at our visioning meeting will be distributed to lake property owners and other interested groups or individuals at the next annual meeting, July 2012.
Action Plan
1. Remove the remaining portion of the wandering BOG to preserve water quality and clarity. This will also preserve the personal property (boats, docks and shorelines) of the property owners. This is schedule to be done on the weekend of Sunday, June 3 and Monday, June 4, 2012. The chairman of the 2012 bog committee is Bob Seemann (director on the board) and he has the experience of the 2011 move. His phone number is 218-682-3332. The process will be to cut the bog into 15 by 15 foot pieces and propel them to the public access (with a DNR permit) by use of pontoons and large boats. There they will be removed by a local contractor and disposed of properly. (Last year we removed 75-100 pieces) Due to the fact that the remaining section is larger in size, we should expect a slight increase in cost. We will cut the bog into sections on Sunday and remove it on Monday. The Sunday portion should require a few hours and the Monday portion may require an all day effort from 5:00AM to 7:00PM. We know from past experiences, the cost of the contractor (Lott Excavating) will be approximately $5000.00 and we will have fuel cost around $400.00. Total cost of the project is projected to be round $5400.00 and require 70-100 hours of labor.
2. The second project is the trapping of beavers and keeping our water outlet open to Woman Lake in an effort to control the water level. The outlet can become completely plugged with beaver dams which will stop the flow of water out and raises the level very rapidly. When this happens we have a major erosion issue and the nutrients from the shoreline pollute our water. Our lake contact for this effort is Elmer Schwerin (director on the board). His contact number is 218-682-2952. We have hired Jack Arnold who is a qualified trapper/water way expert to keep this open for the year. The project is a year around effort. The measure of success is the level of water. We will have a annual cost of $800.00 and propose that we include 2011 and 2012 in this request. Total cost of $1600.00 if there is no unforeseen additional cost increases.
3. The Aquatic Plant Survey needs to be updated from our 2005 version. It appears that the 2005 survey will have trouble being recognized by the DNR and state agencies due to the number of survey points and timing of actual samples being taken. We need to have a current survey to detect any problems and to help us qualify for state, DNR and local funding or assistance. We would propose to hire a survey company from the list of qualified companies and have this done if we can secure funding. The person in charge of the survey and its’ results would be Lloyd Thielmann (chairman of BOD) and his phone number is 763-427-5358. We would really have no way to measure the success other than the report provided us. The timeline would be the first half completed in May or early June and the last half completed between July 15th and September 15th. The success of this project would be the reports and their results being shared with the entire lake association and property owners with the follow up steps being recommended. We have been given an estimate of $4950.00 for the most appropriate and most thorough survey by Fortin Consulting, Inc. We will be securing further estimates but this one is given by a member of the association and has been discounted. It will be more complete because of their concern for our lake.
4. Septic system testing is and should be continued to be offered to all property owners on the lake whether they are association members or not. Our consensus is we can save our beautiful lake and water resource by having a few small corrections made and this is a way for us to find them. The person in charge of these is Court Lechert (director on the BOD) and his phone number is 218-682-2696. This will be on going for years to come but for this plan, we would propose the 2012 and 2013 seasons. We anticipate approximately 5 a year @$65.00 per home for a total of $650.00. The success is not measurable but an effort to preserve our water is and should be on going. If it is necessary, the board of directors would be willing to sponsor more of the testing as requested.
5. Seedlings are and will be given to lake associations members who sign up for them. This is a strong encouragement and recommendation for our owners to make lake buffer zones for water runoff , shoreline aesthetics and for our wildlife. The person in charge of our seedling program is Court Lechert (director of BOD) and his phone number is 218-682-2696. Our time line for this is April, May 2012 and the cost estimated by the BOD for this year is $300.00. The success will be measured only when the seedlings have grown into mature plants but the participation of the owners will be a small measure.
6. We are planning to distribute flyers in a effort to educate users of the public access to the dangers of aquatic hitchhikers. No there no cost estimates or action plans in place at this time. These are to be provided at a later date. The parties in charge of this project are Tim Marr (director of BOD), phone number is 218-682-3007 and Court Lechert (director of BOD) phone number is 218-682-2697.
7. We plan to offer educational opportunities to learn about storm water management, native vegetation and invasive species in the near future. We are in need of one person to take the lead to establish timelines and to define costs of this endeavor. We would welcome and look for the possibility of joining other lake associations or groups such as ACCL to educate our property owners in these opportunities. On the same subject, we are setting up an identifying display for the education regarding the main invasive species in our area. We will have a display for people to compare their samples and learn about these species at the Mule Lake Store. This will be little or no cost to us.
V. WATER QUALITY
Water quality monitoring and assessment will continue to be coordinated with Cass County and the Association of Cass County Lakes and we are currently using RMB Environmental Labs.
Secchi disk readings are done during the peak summer months of June through September. The results are compiled at the end of the season.
Mean secchi disk : 3.8 (meters)
Number of Secchi disk readings to calculate mean: 61
Data shown in the table below is from STORET, the U.S. Environmental Protection Agency’s national water quality database. All data in this table are in units of meters. To convert meters to feet, multiply values shown by 3.28 (e.g. 1.2 meters = 3.9 feet).
Year
Average Secchi Reading (meters)
Click on the year at the left to get full information about the data samples for that year.
Average is computed by the months June-Sept.
1988-3.5
1989-4.1
1990-4.0
1991-3.5
1992-3.7
1993-3.9
1994-3.7
1995-3.5
1996-3.9
1997-4.1
1998-3.7
1999-3.7
2000-4.0
2001-3.9
2002-4.3
2003-3.9
2004-4.4
2005-3.7
2006-4.5
2007-4.7
2008-4.7
2009-4.7
Lake Water Quality Assessment
This summary is based on available summer (June through September) data in STORET (STORET is the national water quality data repository developed by the United States Environmental Protection Agency. All water quality data collected by MPCA or received from external groups is placed in STORET.) collected between 2001 and 2010.
Data Quality:
Aquatic Recreation Use Support : Insufficient Information
Lake Water Quality Data Summary
Total Phosphorus Mean: 14.5 ppb (parts per billion)
Total Phosphorus Standard Error : 1.2 ppb
Total Phosphorus # of Observations : 28
Chlorophyll-a Mean : 3.5 ppb
Chlorophyll-a Standard Error : 0.2 ppb
Chlorophyll-a # of Observations : 28
Secchi Disk Mean : 4.2 meters
Secchi Disk Standard Error : 0.1 meters
Secchi Disk # of Observations : 144
www.pca.state.mn.us/water/clmp.html
Alkalinity Mean: 0.0 ppm (parts per million)
Color Mean: 0.00 Platinum-cobalt Units
Carlson Trophic Status for Total Phosphorus : 42.7
Carlson Trophic Status for Chlorophyll-a : 42.8
Carlson Trophic Status for Secchi Disk : 39.2
Overall Trophic Status : Oligotrophic
(O=oligotrophic, M=mesotrophic, E=eutrophic, H=hypereutrophic)
Future Topics
Our Healthy Lakes Visioning session emphasized the importance of water quality and quantity and especially the problem of aquatic hitchhikers and AIS. We are working to monitor and control our DNR public access better to minimize the introduction of aquatic invasive species
VI. LAKE LEVEL
Lake level measurement is conducted by a local volunteer at an established lake point in coordination with the DNR. Figures are reported and recorded by the office of the DNR in Walker, MN.
Period of record: 02/28/1935 to 05/07/2003
# of readings: 80
Highest recorded: 1327.33 ft (05/08/1999)
Lowest recorded: 1323.4 ft (02/28/1935)
Recorded range: 3.93 ft
Average water level: 1325.81 ft
Last reading: 1325.33 ft (09/14/2003)
OHW elevation: 1326.5 ft
Datum: 1929 (ft)
Lake water level report
Lake name: Blackwater County: Cass
Last 10 years of data
Water Level Data
Period of record: 02/28/1935 to 08/22/2011
# of readings: 414
Highest recorded: 1327.33 ft (05/08/1999)
Lowest recorded: 1323.4 ft (02/28/1935)
Recorded range: 3.93 ft
Last reading: 1326.01 ft (08/22/2011)
Ordinary High Water Level (OHW) elevation: 1326.5 ft
Datum: NGVD 29 (ft)
Download lake level data as: [dBase] [ASCII] (If you have trouble try right clicking on the appropriate link and choosing the “Save … As” option.)
Benchmarks
Elevation: 1335.36 ft
Datum: NGVD 29 (ft)
Date Set: 05/02/1989
Benchmark Location
Township: 140
Range: 29
Section: 25
Description: Double horizontal 60d spike in the SW side of a 1.0′ lone oak on the southerly grass knoll in the parking area at the public access. 6/6/89 work report.
Elevation: 1333.43 ft
Datum: NGVD 29 (ft)
Date Set: 05/14/2002
Benchmark Location
Township: 140
Range: 29
Section: 26
Description: At gauge site on the northeast side of lake, a 5/16″ bolt and washer in the north side of a .9′ birch, 2′ south of the southeast corner of the gauge reader’s cabin.
Elevation: 1340.24 ft
Datum: NGVD 29 (ft)
Date Set: 05/07/2004
Benchmark Location
Township: 140
Range: 29
Section: 35
Description: Found 2011 for Gage Run use. 3/8″ x 8″ spike in the southeast side of a 2.2′ Norway pine on top of lake bank, about 40′ left of the top of steps leading to dock, at private residence, 2640 Blackwater Rd NW, Longville.
Period of record: 02/28/1935 to 05/07/2003
# of readings: 80
Highest recorded: 1327.33 ft (05/08/1999)
Lowest recorded: 1323.4 ft (02/28/1935)
Recorded range: 3.93 ft
Average water level: 1325.81 ft
Last reading: 1325.33 ft (09/14/2003)
OHW elevation: 1326.5 ft
Datum: 1929 (ft)
VII. FISHERIES MANAGEMENT PLAN
Blackwater Lake is an all-around good fishing lake. It has a good reputation for big northern pike and walleye. In the spring, anglers do well catching black crappie. All year anglers catch bluegill and other sunfish. As a bonus, anglers also catch quality smallmouth bass.
Northern pike abundance was typical of past surveys and of other lake class 25 lakes. Fish ranged in length from 13.0 to 37.7 inches and had an average length and weight of 21 inches and 2 pounds. There appears to be abundant spawning areas within the lake as well as in Blackwater Creek. Natural reproduction was consistent with a number of different ages (year classes) present in the sample.
Walleye abundance was typical of past surveys and of other lake class 25 lakes. Walleye sampled showed excellent size and ranged in length from 2 to 28 inches. The average length and weight were 17 inches and 2 pounds. Both natural reproduction and stocking are producing walleye for anglers to catch. Growth was typical of other area lakes in the same lake class. Walleye was 18 inches long at five years old.
Bluegill abundance was down from past surveys but was still typical of other lake class 25 lakes. Fish ranged in length from 3 to 8 inches and had an average length and weight of 5.8 inches and 0.16 pounds. The quality of bluegill has not decreased since 1959. Natural reproduction was good with a number ages represented in the sampled fish.
Yellow perch and Cisco are the primary food fish for predator fish such as northern pike and walleye. Yellow perch numbers has declined from past surveys. There appears to be an abundant population of Cisco. Cisco ranged in length from seven to 17 inches.
There is a population of smallmouth in Blackwater that is being caught by anglers. Fish sampled showed good quality ranging in length from 11.7 to 17.0 inches with an average length and weight of 14.6 inches and 1.6 pounds.
Other fish sampled were all three species of bullhead, rock bass, pumpkinseed sunfish, black crappie, largemouth bass, white sucker, and bowfin (dogfish).
Blackwater Lake along with other lakes in the area had a no kill regulation on all largemouth and small mouth bass. This was law from 2004 to 2010. In 2010 the DNR has lifted the regulation to allow the harvest of bass less than 12 inches.
Our lake association yearly donates to the local catch and release program and we support it strongly in an effort to keep our lake the great fishing lake that it is and has been in the past.
Our plan is to work with, assist, and give constructive input to the Minnesota DNR in reference to fisheries management. We see the need for a close working relationship in managing this natural resource on our lake. In the past we voted, as a Lake association, against the catch and release regulations that were proposed for our bass. However, the DNR put into action this six year restriction. Members also are concerned at the size of the walleye stocked in our lake but this is very six much out of anyone’s control as weather and many conditions affect this.
We will work towards this relation in the following manner:
1. To assist the DNR as needed with any special projects, which will result in the improvement of the quality of the fishery. This may include member-fishing surveys.
2. To identify, protect, and enhance existing fish spawning habitat throughout the lake.
3. To work with the resorts and other fishing individuals in the education of the value of a catch and release program. We feel the importance of maintaining a healthy fishery that selected size fish may need to be returned back to the lake. We annually donate to the catch and release program in our area.
4. To keep the natural flow of the water level at the inlet and outlet points.
These acts will contribute to maintaining a healthy fishing population, which may insure the natural functioning of our lake.
For Blackwater Lake the DNR Area Fisheries Manager is Calub Shavlik, DNR Specialist – Fisheries MN DNR, Walker Area Fisheries Office, 07316 State 371 NW, Walker, MN 56484, 218/547-1683 (phone), calub.shavlik@state.mn.us
Mr. Shavlik and his colleagues routinely prepare a fisheries management plan for Blackwater Lake . The fisheries long range goal of the DNR plan is to:
Provide a quality sport fishery with the following species specific population measures:
Cisco:
A. Gillnet catch arte of 2 to 8
Northern Pike:
A. Gillnet catch rate of 3 to 5
B. Proportional Stock Density (PSD) and Relative Stock Density-P (RSD-P) of 60 and 10.
Bluegill:
A. Trapnet catch rate of 30 to 50
B. PSD, RSD-7 and RSD-P values of 50, 15, and 5.
Smallmouth Bass:
Sampling of smallmouth bass in Blackwater Lake has not produced a large enough or consistent enough sample to set realistic goals for abundance or size structure.
Largemouth Bass:
A. Spring electrofishing catch rate of 30 to 50 per hour.
B. PSD and RSD-P values of 70 and 30.
Black Crappie:
A. Gillnet and Trapnet catch rate of 1 to 4 for each gear type. Spring night electrofishing catch rate of 10 to 20 per hour.
Yellow Perch:
A. Gill net catch rate of 5 to 10.
Walleye:
A. Gillnet catch rate of 4 to 7
B. Strong recruitment to stocked year classes.
The DNR Fisheries Management Plan also notes the following limiting factors:
Shoreline Development has negatively impacted fish habitat and water quality. Considerable bulrush removal has occurred on Blackwater Lake.
Mr. Shavlik also shared the following note in mid-April 2011: “Blackwater – we are beginning the revision process and this will be completed by April 2012. The current LMP has a catch and release regulation for largemouth bass and smallmouth bass; this was converted to a 12-inch maximum in 2010 and will be reflected in the amended LMP in 2012. Our office has written a little article for the Blackwater Lake Association Newsletter to be published this spring about our 2011 summer sampling schedule and little history about the Blackwater Lake fisheries.” This article is in the appendix.
Lake information report
Name: Blackwater
Nearest Town: Longville
Primary County: Cass
Survey Date: 07/07/2008
Inventory Number: 11027400
Purchase a walleye stamp. Your voluntary contribution will be used to support walleye stocking.
Public Access Information
Ownership: DNR
Type: Concrete
Description: Public access on northeast shore.
Fishing Regulations:
Special and/or Experimental Fishing Regulations exist on this lake. Please refer to our online Minnesota Fishing Regulations.
Lake Characteristics:
Lake Area (acres): 766.66
Littoral Area (acres): 336
Maximum Depth (ft): 67
Water Clarity (ft): 14.5 (13-16)
Dominant Bottom Substrate: N/A
Abundance of Aquatic Plants : N/A
Maximum Depth of Plant Growth (ft): N/A
Did you know? Each year, DNR fisheries personnel stock game fish fry and fingerlings in lakes lacking habitat for natural reproduction.
Status of the Fishery (as of 07/07/2008)
Blackwater Lake is a 722-acre lake located near Longville, MN that has 7.5 miles of shoreline and a maximum depth of 67 feet. There is a Minnesota Department of Natural Resources (DNR) public access on the north shore of the east bay off County Road 11. The DNR has classified Minnesota’s lakes into 43 different classes based on physical, chemical and other characteristics. Blackwater Lake is in Lake Class 25; lakes in this class are deep, clear, and irregularly shaped lakes.
Blackwater is known as an excellent lake to catch some nice largemouth bass, and the lake has a no-kill regulation for bass requiring all bass caught to be released. Largemouth bass sampled by the DNR in 2008 had a mean length of 13 inches with fish up to 18 inches long sampled. Anglers fishing the deepwater structure might catch a bonus smallmouth bass, which also has to be released due the no-kill regulation. Angler targeting black crappie may find a good evening bite during early spring. Walleye are present in Blackwater Lake and the catch rate was similar to historical catch rates. The mean length and weight were 19 inches and 2.5 pounds. Fish up to 28 inches were sampled. The size structure for walleye consisted of larger fish with 29% of the walleye sampled greater than 20 inches. Northern pike are abundant in Blackwater Lake and the catch rate has been historically high compared to other Lake Class 25 lakes. The mean length for northern pike was 21 inches and fish up to 29 inches were sampled.
Anglers can help maintain or improve the quality of fishing by practicing selective harvest. Selective harvest allows for the harvest of smaller fish for table fare, but encourages release of medium- to large-sized fish. Releasing these fish can help maintain balance in the fish community in Blackwater Lake and provide anglers the opportunity to catch more and larger fish in the future.
Shoreline habitat consists of aquatic plants, woody plants and natural lake bottom soils. Plants in the water and at the waters edge provide habitat, prevent erosion and absorb excess nutrients. Shrubs, trees, and woody debris such as fallen trees or limbs provide good habitat both above and below the water and should be left in place. Natural lake bottom materials like silt or gravel are more ecologically productive than pure sand trucked in for a swimming beach. By leaving a buffer strip of natural vegetation along the shoreline, property owners can reduce erosion, help maintain water quality, and provide habitat and travel corridors for wildlife. More specific information on protecting or restoring shorelines and watersheds is available through the local MNDNR Fisheries office. ?
For more information on this lake, contact:
Area Fisheries Supervisor
07316 State Hwy 371 NW
Walker, MN 56484
Phone: (218) 547-1683
Internet: Walker Fisheries
E-Mail: Walker.Fisheries@state.mn.us
Lake maps can be obtained from:
Minnesota Bookstore
660 Olive Street
St. Paul, MN 55155
(651) 297-3000 or (800) 657-3757
To order, use C0105 for the map-id.
For general DNR Information, contact:
DNR Information Center
500 Lafayette Road
St. Paul, MN 55155-4040
TDD: (651) 296-6157 or (888) MINNDNR
Internet: www.dnr.state.mn.us
E-Mail: info.dnr@state.mn.us
Turn in Poachers (TIP):
To report a violation immediately, 24 hours a day, 365 days a year, call toll-free 1-800-652-9093 or key in #TIP on your cell phone.
For more information click here to go to the DNR Tip website.
VIII. MACROPHYTE SURVEY (Aquatic Plants)
Our goal is for the lake property owners to become aware of deleterious changes in the lake vegetation and be a source of information and assistance, as required.
This will be done in the following manner, using our sub-committees:
1. To assist in the education of property owners how important the indigenous aquatic plant life is to the healthy balance of our lake.
2. To look for significant changes in the weed locations or concentrations, emergence of new or less desirable species, and/ or changes to dominant weed concentrations. This will be done by, locating & listing vegetation areas on the lake and mapping these locations to show growth patterns.
3. To monitor waters for exotic species of plants or animals and report any findings to the proper environmental authorities. This could include the use of DNR specialists to help educate and locate possible Eurasian Milfoil invasion, then continue to work with the DNR in controlling & monitoring.
4. To be responsive to residents with specific vegetation problems, seek recommendations and remedies consistent with good water management practices.
5. To set up a aquatic plant identification station and help our property owners monitor the plant life changes that occur thought out the various seasons.
IX. POSSIBLE FUTURE GOALS
This area of our management plan is open for additional discussion and/ or input from all interested people.
We are rewriting this LMP and going thru this Healthy Lakes process in order to receive the matching grant money that is being offered by the Initiative Foundation which is bringing The Healthy Lakes & Rivers Partnership Program to the lakes of central Minnesota. THANK YOU
Some ideas may include, in no particular order:
A. Public access/control of AIS.
B. Migratory birds/ wildlife.
C. Managing water surface use.
D. Lake directory/update
E. Final removal of wandering bog
F. Continued control of water levels
G. Aquatic plant survey
H. Continued septic system testing
I. Storm water runoff education/buffer zones
J. AIS identification
X. APPENDIX
07/18/2009 Revision
BY-LAWS
BLACKWATER LAKE ASSOCIATION, INC.
I. MEMBERSHIP
(A) ELIGIBILITY
1. Membership in this Association shall be open to all property owners and lease holders on Blackwater Lake.
2. Membership in this Association shall be open to all back property owners and lease holders who have deeded access rights to the above mentioned waters.
(B) EVIDENCE OF MEMBERSHIP
1. Membership shall be evidenced by payment of Thirty Dollars ($30.00) annual (July 1 to June 30 ) dues per family.
2. All members of the family are considered members of the Association by this payment.
3. Separate voting membership may be had by payment of Thirty Dollars ($30.00) annual dues.
(C) VOTING
1. Voting shall be limited to 2 co-owners for each paid membership, and the majority vote shall govern.
(D) PRIVACY
1. With the exception of that information which is a matter of public record, all membership information shall be kept confidential.
2. Lists of property owners and Association membership maybe provided only by authorization of the Board.
II. MEETINGS OF MEMBERSHIP
(A) ANNUAL MEETINGS
1. There shall be an annual meeting of the membership on the Third (3rd) Saturday in July.
2. The Board shall designate the time and place of the meeting.
3. The Board shall give ten (10) days public notice of such.
(B) ELECTION OF OFFICERS AND DIRECTORS
1. Officers and Directors shall be elected at the annual meeting.
(C) ALL MATTERS PERTINENT TO THE PURPOSES OF THE ASSOCIATION MAY BE PRESENTED AT THE ANNUAL MEETING FOR DISCUSSION OR ACTION.
III. OFFICERS
(A) THE OFFICERS OF THE ASSOCIATION SHALL BE:
1. Chairman
2. Vice Chairman
3. Recording Secretary
4. Treasurer
(B) NOMINATION AND ELECTION
1. The officers shall be elected by the membership at the annual meeting.
2. At the time of the Annual Meeting, nominations for Officers may be made from the floor.
3. If no one is nominated, the Chairman shall appoint from the membership, with the concurrence of the Board, member to fill the vacant positions.
(C) DUTIES OF OFFICERS
1. Chairman
The Chairman shall preside at all membership and Board of Directors meetings; and shall represent the Association in matters relating to the Association.
2. Vice Chairman
The Vice Chairman shall assume the duties of the Chairman if the Chairman is unable to do so. The Vice Chairman shall become the Chairman upon resignation of the Chairman and new Vice Chairman shall be appointed.
3. Recording Secretary
The Recording Secretary shall record the minutes of all membership and Board meetings, and keep a complete record of the membership. The Recording Secretary shall also perform other duties as may be required by the Board of Directors.
4. Treasurer
The treasurer shall receive all monies due this Association; shall deposit same in a depository approved by the Board of Directors; shall disburse the funds of the Association; shall present a statement of account at all meetings of the Board of Directors; shall keep a correct record of dues payments for all members and shall make a complete report at the Annual Meeting.
(D) THE OFFICERS SHALL ALSO SERVE AS MEMBERS OF THE BOARD OF DIRECTORS DURING THEIR TERM.
(E) TENURE OF OFFICE
1. Officers shall serve for a period of three (3) years.
(F) VACANCIES
1. Any vacancy in an office shall be filled by the Board of Directors for the balance of the term.
(G) INDEMNIFICATION OF THE BOARD OF DIRECTORS
1. Each person who shall be, is, or has been an officer of or an executive committee member of this Association, shall be indemnified by this Association against expenses, judgments/s, including attorney fee/s necessarily incurred by such person in connection with the defense or settlement of any action, suit, or proceeding to which they are a party, by reason of their being or have been an officer of or an executive committee member of this Association; unless said person shall be adjudge in such action, suit, or proceeding to be liable for personal misconduct in the performance of their duties to this Association.
IV. BOARD OF DIRECTORS:
(A) QUALIFICATIONS
1. All members of the Board must be members in good standing of the Association.
(B) MEMBERS
1. Elected Officers
2. Immediate Past Chairman (Immediate Past Chairman shall serve a maximum term of two (2) years).
3. Four (4) Directors shall be elected to represent each designated section of the lake (North, South, East, and West). The four (4) Directors shall serve for a term of two (2) years.
4. Member-at-Large Director. The Member-at-Large Director shall serve a term of one year.
(C) THE CHAIRMAN SHALL SERVE AS CHAIRMAN OF THE BOARD OF DIRECTORS.
(D) QUORUM
1. A quorum to conduct business shall be the Directors present.
(E) MEETINGS OF THE BOARD
1. The Board shall meet at least once from May through October at the time and place specified by the Chairman. The Board shall also meet at the time of the Annual Meeting.
2. Special meetings of the Board may be called by the Chairman upon giving ten (10) days notice sent to their lake and/or permanent address. This notice shall specify the time and place of the meeting and its purpose.
(F) DUTIES
1. To carry out such policies and procedures as to best effectuate the purposes of the Association.
2. To give final approval to all expenditures.
(G) VACANCIES
1. Vacancies shall be filled by appointment by the Chairman with the approval of the Board.
(H) STANDING COMMITTEES
The Board may establish committees to undertake programs in specialized areas of interest with at least one Board member serving on each committee.
Present Committees are:
1. Fish Management
2. Water Quality and Healthy Lakes
3. Membership
4. Waterway Task Force
5. Secchi Disc
6. Bog Control
7. Land Acquisition
V. MEETINGS
(A) Roberts Rules of Order shall govern all meetings of the Association.
VI. AMENDMENT OF BY-LAWS
(A) These By-Laws may be altered, amended, or repealed by the members at a regular or special meeting by a majority vote of the members present at such meeting.
THE ABOVE BY-LAWS WERE APPROVED AND ADOPTED BY A MEETING OF THE BLACKWATER LAKE ASSOCIATION, INC. THIS 31ST DAY OF AUGUST, 1996
THE ABOVE BY-LAWS WERE AMENDED BY A MEETING OF THE BLACKWATER LAKE ASSOCIATION, INC. THIS 5TH DAY OF SEPTEMBER, 1998.
THE ABOVE BY-LAWS WERE AMENDED BY A MEETING OF THE BLACKWATER LAKE ASSOCIATION, INC. THIS 15TH DAY OF JULY, 2000
THE ABOVE BY-LAWS WERE AMENDED BY A MEETING OF THE BLACKWATER LAKE ASSOCIATION, INC. THIS 17TH DAY OF JULY, 2004
THE ABOVE BY-LAWS WERE AMENDED BY A MEETING OF THE BLACKWATER LAKE ASSOCIATION, INC. THIS 18TH DAY OF JULY, 2009 AS FOLLOWS:
I. (B) EVIDENCE OF MEMBERSHIP, 1. Membership shall be evidenced by payment of Thirty Dollars ($30.00) annual (July 1 to June 30) dues per family, and 3. Separate voting membership may be had by payment of Thirty Dollars ($30.00) annual dues.
IV. (B) MEMBERS, 2. Immediate Past Chairman (Immediate Past Chairman shall serve a maximum of two (2) years).
Blackwater Lake Fishery and Fish Management Facts
Blackwater Lake is a 722-acre lake (336 acres considered littoral, i.e. 15 feet deep or less) with 7.5 miles of shoreline and a maximum depth of 67 feet. There is a DNR-owned public access on the north shore of the east bay off County Road 11. The DNR classified Minnesota’s lakes into 43 different lake classes based on physical, chemical, and other characteristics. Blackwater Lake is in Lake Class 25; lakes in this class are deep, clear, and irregularly shaped. Other area lakes in Lake Class 25 are Big Boy, Birch, Girl, Inguadona, and Long.
Blackwater Lake has an extensive history of fisheries investigations that includes 15 investigations dating back to 1959. DNR fisheries investigations are typically carried out using gill nets set on the bottom of the lake to sample deeper water fish species, trap nets to sample near shore populations, and in some cases spring electrofishing to sample bass populations. A creel survey was conducted on a number of lakes in the Longville area in 2007 and included Blackwater Lake. A creel survey consisted of a clerk interviewing anglers which was used to estimate fishing pressure, catch rates, and harvest. The 2007 creel survey found that sunfish and black crappie made up the majority of the harvest on Blackwater Lake with 53.8 and 19.4 percent of the total harvest, respectively. However, largemouth and smallmouth bass accounted for the majority of the total catch (55.3 percent). Walleye catch and harvest rates were above or near the middle value for Lake Class 25 lakes. The average length and weight of harvested walleye in the 2007 creel survey was 17.52 inches and 1.90 pounds.
Blackwate Lake has a history of being a very good lake for catching largemouth bass. Experimental regulations were implemented in 2004 designating Blackwater Lake as catch and release only for largemouth and smallmouth bass. The goal of this regulation was to improve the size structure of largemouth bass and protect large smallmouth bass from harvest. This regulation was converted to a 12 inch maximum (all bass 12 inches in length or longer must be immediately released) in 2010. Spring electrofishing is our primary tool for assessing the largemouth bass population in Blackwater Lake. Catch rates ranged from 34.56 to 89.83 fish per hour in past assessments. The most recent assessment (2009) caught 89.14 fish per hour, but there was no significant change in catch rates between the pre-regulation era and the post-regulation era. However, the proportion of larger bass in electrofishing samples was higher in the three assessments since the special regulations went into effect than in all prior assessments. A full evaluation and review process to determine the effectiveness of this regulation will occur in 2016.
Walleye stocking in Blackwater Lake began in the 1950s with fingerlings, and stocking occurred in 29 years during this 60 year period. Most recently, walleye fingerlings were stocked in Blackwater Lake in the fall of 2006, 2008, and 2010 as prescribed in the current lake management plan. The current stocking regime will be evaluated following a fish population assessment that will be carried out this summer. Walleye numbers in the gill nets, our primary tool for assessing relative abundance, ranged from 1.42 to 4.00 fish per gill net in past investigations. Historical walleye gillnet catch rates in Blackwater Lake fall within the normal range (i.e. between the 25th to 75th percentile) for all Class 25 lakes in Minnesota (1.25 to 5.50 fish per gillnet). Walleye catch rates have been relatively stable in recent assessments with catch rates above three per gillnet in four of the previous five assessments. The most recent population assessment in 2008 caught 3.92 walleye per gillnet.
Blackwater Lake received the following amounts of walleyes recently:
2006: 692 pounds, approximately 7,653 fingerlings
2008: 672 pounds, approximately 20,448 fingerlings
2010: 678 pounds, approximately 12,509 fingerlings
The reason for the different numbers of fingerlings for a similar weight of fish across years is due to differences in sizes of fingerlings. Fingerling size is influenced by a variety of factors including growing conditions (length of summer growing season, water temperatures, etc) and where the fish were raised (different ponds produce different sizes of fish, etc). Most of the fish in 2006 and 2008 came from DNR ponds in the Glenwood Area. The fingerlings stocked in 2010 were purchased by the state from a private grower. There are not enough suitable ponds in the Walker area to grow our own fingerlings so the DNR often will rely on other DNR Area Fisheries or private growers to provide us with our fingerlings.
Northern pike gill net catch numbers have been following a noticeable upward trend since the early 1990s. The most recent gillnet catch rate (2008) was the highest ever recorded in Blackwater at 11.42 fish per net. This is higher than the range typical of Class 25 lakes (3.13 to 8.50 fish per gill net) and nearly three times higher than the 1991 catch rate of 4.13 fish per net. In 2007, lake association members participated in ice-out trap netting to remove small northern pike with the goal of reducing overall northern pike numbers and improving size structure. While some northern pike were captured and removed, the numbers were not high enough to have a significant impact on the population.
Yellow perch, the primary forage species for walleye and northern pike in many Minnesota lakes, have historically been stable but relatively low in numbers in Blackwater Lake. The 2008 assessment caught 2.17 yellow perch per gill net, lower than the normal range for Class 25 lakes (2.50 to 24.17). Yellow perch gill net catch rates ranged from 1.67 to 7.88 fish per net in past investigations. Blackwater Lake has a stable and relatively high number of bluegill based on trap net catch rates dating back to 1959. Trap net catch rates have historically ranged from 29.22 to 66.58. The 2008 assessment caught 33.75 bluegills per trap net, which is within the normal range for Class 25 lakes (5.61 to 42.27 bluegills per trap net). Bluegills up to 7.8 inches were sampled in 2008. Black crappie numbers in assessments have historically been low, ranging from 0.08 (2008) to 3.83 per trap net. Black crappie up to 11.73 inches were sampled (spring electrofishing) in 2008. Other species sampled in Blackwater Lake include smallmouth bass, tullibee, white sucker, rock bass, pumpkinseed sunfish, bowfin, brown bullhead, and yellow bullhead.
The Walker Area Fisheries office plans to conduct spring electrofishing targeting bass this year on Blackwater Lake. In addition, a population assessment is scheduled for early July using trap nets and gill nets. You may also see a creel clerk on the water this summer interviewing anglers. This clerk will be collecting information on species targeted, times spent fishing, and catch and harvest numbers to determine total fishing pressure, catch and harvest rates, and angler demographic information on a number of lakes in the Longville area, including Blackwater. The information collected will help manage the Blackwater Lake fishery and your participation is greatly appreciated. Feel free to contact the Walker Area Fisheries Office at 218-547-1683 with any questions or to request more detailed information. You can also email Benjamin.vondra@state.mn.us for more information or any questions you may have.
The fish management committee co/chairs Lloyd Thielmann and Dick Clough
Glossary
Aerobic: Aquatic life or chemical processes that require the presence of oxygen.
Algal bloom: An unusual or excessive abundance of algae.
Alkalinity: Capacity of a lake to neutralize acid.
Anoxic: The absence of oxygen in a water column or lake; can occur near the bottom of eutrophic lakes in the summer or under the ice in the winter.
Benthic: The bottom zone of a lake, or bottom-dwelling life forms.
Best Management Practices: A practice determined by a state agency or other authority as the most effective, practicable means of preventing or reducing pollution.
Bioaccumulation: Build-up of toxic substances in fish (or other living organism) flesh. Toxic effects may be passed on to humans eating the fish.
Biological Oxygen Demand: The amount of oxygen required by aerobic microorganisms to decompose the organic matter in sample of water. Used as a measure of the degree of water pollution.
Buffer Zone: Undisturbed vegetation that can serve as to slow down and/or retain surface water runoff, and assimilate nutrients.
Chlorophyll a: The green pigment in plants that is essential to photosynthesis.
Clean Water Partnership (CWP) Program: A program created by the legislature in 1990 to protect and improve ground water and surface water in Minnesota by providing financial and technical assistance to local units of government interested in controlling nonpoint source pollution.
Conservation Easement: A perpetual conservation easement is a legally binding condition placed on a deed to restrict the types of development that can occur on the subject property.
Cultural eutrophication: Accelerated “aging” of a lake as a result of human activities.
Epilimnion: Deeper lakes form three distinct layers of water during summertime weather. The epilimnion is the upper layer and is characterized by warmer and lighter water.
Eutrophication: The aging process by which lakes are fertilized with nutrients.
Eutrophic Lake: A nutrient-rich lake – usually shallow, “green” and with limited oxygen in the bottom layer of water.
Exotic Species: Any non-native species that can cause displacement of or otherwise threaten native communities.
Fall Turnover: In the autumn as surface water loses temperature they are “turned under” (sink to lower depths) by winds and changes in water density until the lake has a relatively uniform distribution of temperature.
Feedlot: A lot or building or a group of lots or buildings used for the confined feeding, breeding or holding of animals. This definition includes areas specifically designed for confinement in which manure may accumulate or any area where the concentration of animals is such that a vegetative cover cannot be maintained. Lots used to feed and raise poultry are considered to be feedlots. Pastures are not animal feedlots.
Groundwater: water found beneath the soil surface (literally between the soil particles); groundwater is often a primary source of recharge to lakes.
Hardwater: Describes a lake with relatively high levels of dissolved minerals such as calcium and magnesium.
Hypolimnion: The bottom layer of lake water during the summer months. The water in the hypolimnion is denser and much colder than the water in the upper two layers.
Impervious Surface: Pavement, asphalt, roofing materials or other surfaces through which water cannot drain. The presence of impervious surfaces can increase the rates and speed of runoff from an area, and prevents groundwater recharge.
Internal Loading: Nutrients or pollutants entering a body of water from its sediments.
Lake Management: The process of study, assessment of problems, and decisions affecting the maintenance of lakes as thriving ecosystems.
Limnology: The study of bodies of freshwater (as lakes)
Littoral zone: The shallow areas (less than 15 feet in depth) around a lake’s shoreline, usually dominated by aquatic plants. These plants produce oxygen and provide food, shelter and reproduction areas for fish & animal life.
Local Unit of Government: A unit of government at the township, city or county level.
Mesotrophic Lake: A lake that is midway in nutrient concentrations (between a eutrophic and oligotrophic lake) characterized by periodic problems with algae blooms or problem aquatic vegetation.
Native Species: An animal or plant species that is naturally present and reproducing.
Nonpoint source: Polluted runoff – nutrients or pollution sources not discharged from a single point. Common examples include runoff from feedlots, fertilized lawns, and agricultural fields.
Nutrient: A substance that provides food or nourishment, such as usable proteins, vitamins, minerals or carbohydrates. Fertilizers, particularly phosphorus and nitrogen, are the most common nutrients that contribute to lake eutrophication and nonpoint source pollution.
Oligotrophic Lake: A relatively nutrient-poor lake, characterized by outstanding water clarity and high levels of oxygen in the deeper waters.
Nutrient: A substance that provides food or nourishment, such as usable proteins, vitamins, minerals or carbohydrates. Fertilizers, particularly phosphorus and nitrogen, are the most common nutrients that contribute to lake eutrophication and non-point source pollution.
pH: The scale by which the relative acidity or basic nature of waters are accessed,
Photosynthesis: The process by which green plants produce oxygen from sunlight, water and carbon dioxide.
Phytoplankton: Algae – the base of the lake’s food chain, it also produces oxygen.
Point Sources: Specific sources of nutrient or pollution discharge to a water body, i.e., a stormwater discharge pipe.
Riparian: The natural ecosystem or community associated with river or lake shoreline.
Secchi Disc: A device measuring the depth of light penetration in water.
Sedimentation: The addition of soils to lakes, which can accelerate the “aging” process by destroying fisheries habitat, introducing soil-bound nutrients, and filling in the lake.
Spring turnover: After ice melts in the spring, warming surface water sinks to mix with deeper, colder water. At this time of year all water is the same temperature.
Thermocline: During summertime deeper lakes stratify by temperature to form three discrete layers; the middle layer of lake water in known as the thermocline.
Trophic Status: The level of growth or productivity of a lake as measured by phosphorus, content, algae abundance, and depth of light penetration.
Watershed: The surrounding land area that drains into a lake, river, or river system.
Zooplankton: Microscopic animals.
Common Biological or Chemical Abbreviations
BOD Biological Oxygen Demand
°C degree(s) Celsius
cfs cubic feet per second (a common measure of rate of flow)
cfu colony forming units (a common measure of bacterial concentrations)
chl a Chlorophyll a
cm centimeter
COD Chemical Oxygen Demand
Cond conductivity
DO dissolved oxygen
FC fecal coliform (bacteria)
ft feet
IR infrared
l liter
m meter
mg milligram
ml milliliter
NH3-N nitrogen as ammonia
NO2-NO3 nitrate-nitrogen
NTU Nephelometric Turbidity Units, standard measure of turbidity
OP Ortho-phosphorus
ppb parts per billion
ppm parts per million
SD Standard Deviation (statistical variance)
TDS total dissolved solids
TN total nitrogen
TP total phosphorus
TSI trophic status index
TSI (C) trophic status index (based on chlorophyll a)
TSI (P) trophic status index (based on total phosphorus)
TSI (S) trophic status index (based on secchi disc transparency)
TSS total suspended solids
mg/l micrograms per liter
mmhos/cm micromhos per centimeter, the standard measure of conductivity
UV Ultraviolet
Guide to common acronyms
State and Federal Agencies
BWSR Board of Soil & Water
COE U.S. Army Corps of Engineers
CRP Conservation Reserve Program – A federal government conservation program
DNR Department of Natural Resources
DOJ United States Department of Justice
DOT Department of Transportation
DTED Department of Trade and Economic Development
EPA U.S. Environmental Protection Agency
EQB MN Environmental Quality Board
LCCMR Legislative-Citizen Commission on Minnesota Resources
MDH Minnesota Department of Health
MPCA Minnesota Pollution Control Agency
OEA MN Office of Environmental Assistance
OSHA Occupational Safety and Health Administration
RIM Reinvest In Minnesota – a State of Minnesota Conservation Program
SCS Soil Conservation Service
SWCD Soil & Water Conservation District
USDA United States Department of Agriculture
USGS United States Geological Survey
USFWS United States Fish & Wildlife Service
Regional, watershed, community development, trade and advocacy groups
ACCL Association of Cass County Lakes
AMC Association of Minnesota Counties
APA American Planning Association
COLA Coalition of Lake Associations
IF Initiative Foundation
LARA Cass County Lakes & Rivers Alliance
LMC League of Minnesota Cities
MAT Minnesota Association of Townships
MLA Minnesota Lakes Association
MSBA Minnesota School Board Association
MCIT Minnesota Counties Insurance Trust
Mid-MnMA Mid-Minnesota Association of Builders
MLA Minnesota Lakes Association
MnSCU Minnesota State Colleges and Universities
RCM Rivers Council of Minnesota