by Cal Killen
Glen Arbor, Michigan
This is the story of how the Glen Lake Association (GLA) applied modern technology to their management of Glen Lake’s water level. The results are more accurate water level control at substantially less cost, while making it safer and easier for personnel. Along the way, they learned facts about the watershed system never known before.
Glen Lake is one of Michigan’s finest lakes. Actually a set of five connected lakes (Big Glen, Little Glen, Big Fisher, Little Fisher and Brooks) in northwest lower-Michigan, it covers about 6,000 acres at depths reaching 130 feet. The output of Glen Lake is the source of the Crystal River which meanders five miles before emptying into Lake Michigan; only one mile away. The flow into the Crystal River is controlled by a dam 18 feet wide with two independent swinging gates. Atypical in Michigan, this dam is not controlled by a drain commissioner, but by members of the GLA, and it has been that way since the dam was built many years ago. So the GLA formed the Water Level Committee (WLC) in 1955 to manage the Glen Lake level and Crystal River flow as much as nature would allow.
Law suits over the years have resulted in a court ordered set of rules for both the upper/lower bounds of Glen Lake’s water level and the Crystal River’s water flow minimums. This means that lake-level/river-flow management is not a hobby for the GLA; it’s a legal mandate. A court appointed Technical Committee keeps close watch on the lake-level/river-flow operations and reports status to the court annually. To accommodate the legally mandated limits, the Technical Committee has approved a daily target lake level within a narrow tolerance. The days of summer have a relatively high lake level target (good for boating, enjoying the beach and supplying water to the river during drought periods) and winter days have a low lake level target (to mitigate ice damage and minimize beach erosion). The spring and fall days have targets that are a gradual transition between summer highs and winter lows. Regardless of lake level, the river flow must be kept above a certain minimum water flow so as not to adversely affect the ecology of the river.
Chapter 1: Determining Lake Level
The first thing required in lake-level/river flow management is to be able to determine the actual elevation of the lake level, and understand how it changes over time due to the various water inputs and outputs. Only after having that information does one have a chance of managing the balance of lake-level and river flow through dam gate settings.
For determining lake level, a set of three staff gauges were placed at strategic positions around the lakes to determine water levels. These gauges were surveyed so the actual sea level elevation of the water can be calculated. One of the staff gauges is the standard used for determining legal lake level. Another is used as a backup. The third is used to measure the water level at a location just upstream of the dam – where the water level can vary several inches lower than that at the other gauges. Water levels are supposed to be measured and recorded at these points at least twice a week – more often when weather events dictate. It is not always possible to read the gauges, however. Sometimes windy conditions generate waves that make it impossible to take a precise reading of the staff gauge. At other times, ice and snow obscure the markings on the staff gauge, making it equally impossible to determine an exact reading. Often, the times when lake level knowledge is most important are the times when weather conditions are at their worst. Going out to read the gauges during storms (especially in winter) can be a challenging task for the WLC members.
Chapter 2: Automation Begins
Partly due to the fact that all the WLC members are dedicated volunteers who want precise measurements and partly because many of them are engineers and “tinkerers,” it was decided in 2010 to install an automatic lake level sensor. The sensor was installed very close to the staff gauge used to determine the legal lake level elevation, and about three feet below the water’s surface. Using a 100-foot underground cable, the sensor was attached to a communication station that contained a data logging device, a cellular modem, a battery and a solar cell. The sensor is an accurate pressure transducer which reads water depth, not elevation. The sensor is compensated for atmospheric pressure changes. Every 15 minutes the data logger records the “depth” of water over the sensor. Every hour the modem is automatically turned on so a remotely located computer server can upload the latest depth readings. The actual elevation of the sensor has been determined through comparison with the staff gauge readings, so this elevation can be added to the depth reading to get the actual lake level.
Using automatic sensors to gather lake level data proved to be very accurate and reliable. The sensor is accurate to 1/8-inch and any fluctuations in the lake level due to wind gusts or waves are eliminated by averaging over time. The WLC realized the advantage right away; the technique gave them accurate information on an hourly basis. And with a new website, the information was available to all members without leaving the comfort of their homes.
Chapter 3. The Website Begins
Turning “raw data” from both the automatic and manual gauges into “information” that can be used to make decisions was solved by the introduction of the WLC website. Many thousands of lines of code were written to generate graphs and tables that make it easy to know things like:
- Is the lake level on target?
- Is the lake level trending in the right direction?
- How long will it take before the lake level is in (or out) of target tolerance?
- How much did it rain last night?
The WLC soon developed a wide set of charts and graphs on the website that answered these questions quickly and accurately. What’s more, the information led to the discovery of facts about the lake never known before. For example, the WLC discovered a resonance between Big and Little Glen – water sloshes back-and-forth under the Narrows Bridge about every 40 minutes.
The sensor also records battery voltage in the station. If the voltage goes below 12 v. the website automatically alerts the WLC with an email warning. Most of the time this means someone has to brush the snow off of the solar cell.
Chapter 4: Determining River Flow
A fourth staff gauge (called a “stream gauge”) was installed years ago in the Crysta River just downstream from the dam. This gauge was used in conjunction with a U. S. Geological Survey (USGS) provided rating table to estimate Crysta River water flow. This is a very common method for calculating river flow; the principle being that the higher the water level in the river, the higher the water flow. One reads the stream gauge in the river and refers to the rating table, which then yields an estimated river flow. But as nature would have it, the conditions of the river are always changing, and changes degrade the accuracy of this method. Small effects can be due to natural changes in the river bed and growth of vegetation on the banks of the river. Larger effects can be due to trees and branches falling into the river (downstream or upstream), ice/snow in the river, and canoes banging in to the stream gauge. One of the most common reasons for inaccurate river flow estimations was found to occur after a large rain event or snow melt. Water flows into the river from various places below the dam which swells the river and causes this method to overestimate the flow over the dam by as much as 20%.
Because conditions continually change, regular re-calibration of the adjustment factor applied to the stream gauge readings was required. With a flow device, the USGS manually measured water flow in the river at a cross section just below the dam, taking measurements every foot at various depths. These measurements were summed to produce an accurate river flow for that point in time. Comparing that actual flow to the estimated flow from the rating table produced an adjustment or “shift” value for the WLC to use. After a calibration, the WLC members could get an accurate river flow measurement at the dam by reading the stream gauge, adding or subtracting the “shift” and then applying that value to the rating table. Since the WLC wanted to be very precise on measuring water flow – especially at low flows when we were close to the court mandated minimum – calibrations were done five times a year at a cost of $3,000 every year to the Glen Lake Association
Unfortunately, the accuracy of the re-calibration proved to be short-lived. As soon as the re-calibration was completed, the river would change. When the WLC would get a new shift, especially one that was a significant change from the previous shift, they knew that they had been recording imprecise river flows for some unknown time and amount. Besides that, no amount of calibration could result in accurate river flow measurements after a precipitation event mentioned above. In addition, reading the stream gauge in wintertime was a chore at best and a safety hazard at worst. WLC volunteers had to walk a distance through unfavorable terrain, stand on a sometimes ice-covered bank to read the stream gauge 10-feet out in the river. The WLC started thinking about a better way to do business.
Chapter 5: Making Dam Gate Adjustments
The Crystal River dam was first built in the early 1900’s and was originally adjusted by adding or removing boards a cross the dam. The dam was remodeled in 2002 to allow for easier and finer adjustments. Two 7 ½-foot wide gates were added side by side, hinged at the bottom and adjusted by winching them up or down. The gates travel just under 24” from fully open to fully closed.
To make a dam adjustment, one WLC member cranks the winch wheel while another WLC member measures the vertical distance between the gate and a reference point on the side of the dam. A specially calibrated “yard stick”, complete with a leveling bubble, is used to make sure the measurements are accurate. Eight rotations of the winch wheel results in about one inch of vertical movement of the gates, which affects the dam flow anywhere from three to 10 cubic feet per second (CFS). After making an adjustment, the river needs some time to settle into its new level. So after waiting 20 minutes to allow for this settling, another reading is taken of the stream gauge, another calculation of the dam flow is made from the rating table, and additional adjustments are made as needed. All of these measurements and adjustments are recorded and the data kept for years.
Chapter 6: Automation Continues
Enthused with the results of the automatic sensor installed the year before, the WLC decided to take the much bigger step of fixing the problems related to calculating dam flow. There were four parts to this solution:
1. Install another automatic sensor 25 feet in front of the dam,
2. Develop a weir equation that calculates dam flow given the gate setting,
water level and dam geometry, and
3. Regularly compare river flows (using several manual methods) to the
weir equation spanning a year and over a wide range of flows to “tune”
the equation, and
4. Report process and findings to the Technical Committee regularly.
Given the physical characteristics of the Crystal River dam, the standard rectangular weir equation was applied:
Q = CE W H 1.5
“CE” is a constant (around 3.3) which was empirically determined by comparing manually determined water flow to calculated results.
“W” is the width of the dam gate. Since the dam has two gates, the weir equation needed to be used twice, once for each gate. The values are summed for the total river flow. In this way, the gates can be set at far different elevations and the flow is calculated correctly.
“H” is the “head,” or difference in elevation between the water level above the dam and gate setting. Note that calculating the head requires a modeling of gate setting to gate elevation.
In the fall of 2011, this automatic sensor was installed and calibration of the weir equation started. Over the next year, using many manual river flow measurements from the USGS and the WLC at a broad range of flows, the weir equation was calibrated and found to be far more accurate than the stream gauge estimating method.
In the summer of 2013 the Technical Committee was convinced of the accuracy of the weir equation. With their support, the court recognized the advancement and gave the WLC permission to use the weir equation for making dam setting decisions.
Chapter 7: The Website Expands
The backbone to the WLC operations and automation is the website and the programming behind it. There are several parts to the website:
- Lake levels, trends and targets
- River flow trends and limits
- Water temperature
- Battery voltage
- Precipitation events
- Calibration comparisons
- Raw data storage and retrieval
- Current conditions at-a-glance
- Monthly reports
- Manual Input
- Staff gauge readings
- Dam settings
- Comments about current conditions
- River flow : Lake level : Dam setting
- Dam setting recommendations
- Team Membership
- Contact information
- Schedule of assignments
Besides the website, there are programs on the computer server that run automatically to update data, check for certain conditions, and send email alerts. With these advancements in the website programming we updated the posting on the GLA public website to include river flow and precipitation events.
Now that the website has been running for several years capturing data every 15 minutes, enough data exists to do some statistical analysis. One of the calculators on the website allows the user to enter two of three values (river flow, lake level, dam setting) and it will produce the statistical plot of the third value.
Chapter 8: Results
With the fine efforts of many WLC members, lake level management has been made easier, safer and more accurate. It also pays for itself. Since the flow estimating method is no longer used, there is no need for the USGS to make river flow re-calibrations. By canceling that contract the WLC recaptured the expense of an automation station in a single year. But there is more to be learned. Now that data exists to be “mined,” the WLC can learn things like:
- amount of groundwater in and out of the lake system
- evaporation values
- daily lake level targets to maximize water level and minimize shore erosion
- methods to minimize flooding of Crystal River
And with the capability of adding additional sensors to the system, the WLC can learn even more about water quality and the effects of different weather events. We highly recommend using these methods for other lakes.
By David Marks, Wildlife Biologist, USDA Wildlife Services
People live on the water for many reasons including the appeal of being close to nature. Mute swans are beautiful animals and many people appreciate having a family group to watch. But it is an invader to Michigan waters that may potentially threaten the natural value of the places you care about.And as the mute swan populations have grown, people are beginning to experience their negative effects on the environment, native wildlife, and even human safety. Destruction of native habitat is the primary concern about mute swans.Feeding on aquatic vegetation, a single bird can eat up to eight pounds per day. Thus, a large group of swans in an area can drastically affect the habitat that other wildlife species depend on. Additionally, the mute swans out-compete native species for resources, both food and breeding habitat.If your lake is highly developed and lacks native habitat and wildlife, you may wonder why mute swans should concern you. Consider the bigger picture: the mute swans on your lake will continue to be a source of more mute swans, which will spill over into high-quality wildlife areas.
Individual mute swans can also become hostile towards humans and pets. This usually occurs in older male mute swans that are protecting their nests and cygnets. As years go by, an individual male may become more and more assertive.Aggressive behavior may begin as simply hissing and swimming around a person to deter them. But sometimes the behavior escalates to flying at people when unprovoked or actually making contact with people, and the birds become a significant threat to human or pet safety. If this situation does occur, a special permit can be issued to remove that particular aggressive swan.
Basically, two options exist for mute swan population control: removing the birds or treating their eggs so they will not hatch. Removing the birds is more effective as far as reducing the numbers of swans both on the site itself and the overall mute swan population in Michigan.However, some local residents may find it unacceptable because the birds will be killed.Egg treatments may be the only option acceptable to residents, and will gradually reduce the local mute swan population if conducted annually and will help reduce aggressive behavior towards humans during the summer.Relocation of mute swans is not an option because they are an invasive species and will just cause damage at another location or even fly back to the original site.
Since 2006, USDA Wildlife Services has been working cooperatively with the Michigan Department of Natural Resources in controlling the mute swan population throughout Michigan, with support from a broad range of stakeholders. These include the US Fish and Wildlife Service, several Native American tribes, Ducks Unlimited, the Michigan United Conservation Clubs, the Michigan and National Audubon Society, and the Michigan Lakes and Streams Association to name a few. Wildlife Services conducts mute swan management through funding provided by a Great Lakes Restoration Initiative grant, at no cost to the landowner(s). In 2013, Wildlife Services conducted management and resolved mute swan conflicts at 76 sites throughout Michigan.
If you would like to learn more about mute swan impacts and what options you have, you can turn to several resources. The best resource is the State’s website at www.michigan.gov/muteswanswhich has the facts about mute swans, including a list of peer-reviewed scientific literature, as well as the laws and regulations and permit applications. To discuss the specific issues of your mute swan situation, you can contact your local MDNR biologist (online list) or a USDA Wildlife Services biologist (517-336-1928). USDA Wildlife Services works with the local parties to resolve their conflicts with mute swans and only conducts management actions at the request of the locals from that lake or river.
Register Now for the
Michigan Inland Lakes Convention!
The Early Bird Registration Discount
Ends on March 1st, 2014
Bill Rustem, Director of Strategy
for Governor Snyder
Announced as Event Plenary Speaker
Michigan Inland Lakes Convention:
Partnering to Protect Michigan’s Inland Lakes
May 1st, 2nd and 3rd , 2014
Boyne Mountain Resort
Boyne Falls, Michigan
The Michigan Inland Lakes Partnership is pleased to announce that registration is open for the inaugural Michigan Inland Lakes Convention, May 1-3 at Boyne Mountain Resort in Boyne Falls. Register by March 1 to take advantage of the Early Bird discount!
Bill Rustem, Director of Strategy for Governor Rick Snyder, will join us for a plenary address on Friday morning, May 2nd. Mr. Rustem will focus on the conference theme of partnerships, with his address “Successful Partnerships – Importance to Government”. Prior to his current position in the Governor’s office, Mr. Rustem was an owner of Public Sector Consultants (PSC) and was the firm’s president and CEO. While at PSC, Mr. Rustem directed studies on the status of Michigan cities, wastewater treatment needs, recycling, and land use. Before joining the firm, Mr. Rustem was Gov. William G. Milliken’s chief staff advisor on environmental matters and Director of the Governor’s Policy Council.
The Convention presents an opportunity for lake enthusiasts, lake professionals, researchers, local government officials and anyone else interested in protecting our water resources to participate in three days of educational presentations and discussion, in-depth workshops, tours, exhibits and much more focused on Michigan’s 11,000 inland lakes.
The 2014 Michigan Inland Lakes Convention is brought to you by the Michigan Inland Lakes Partnership, launched in 2008 to promote collaboration to advance stewardship of Michigan’s inland lakes. The Convention is a cooperative effort between many public and private organizations including the Michigan Chapter of the North American Lake Management Society, Michigan Lake and Stream Associations, Inc., Michigan State University Extension, Michigan Natural Shoreline Partnership, Michigan Department of Natural Resources, Michigan Department of Environmental Quality, and the Michigan State University Institute of Water Research.
Visit the Michigan Inland Lakes Partnership website at http://michiganlakes.msue.msu.edu to register. Questions about the Convention can be directed to Dr. Jo Latimore, MSU Department of Fisheries and Wildlife, at firstname.lastname@example.org or 517-432-1491.
To download a Michigan Inland Lakes Convention flyer, click here
Story and Photo by Scott Brown, ML&SA Executive Director
Starry stonewort (Scientific Name: Nitellopsis obtusa), a member of the Characeae family, and considered a beneficial, though increasingly rare “connoisseur of clean water” within its native range of northern Europe and Asia, was first observed as an invasive species within the North American waters of the St. Lawrence Seaway in 1978, and was later detected in the St. Clair-Detroit River system by the summer of 1983. Discovered in Michigan inland lakes in February of 2006, successful colonization of over one hundred twenty five of the state’s inland lakes had been confirmed by the Michigan Department of Environmental Quality by the spring of 2012. Due to the repeatedly observed ability of invasive starry stonewort to degrade ecologically sensitive areas of shallow water habitat within colonized inland lakes, federal and state government agencies, including the United States Aquatic Nuisance Species Task Force and the Michigan Department of Environmental Quality, have classified starry stonewort as a highly invasive aquatic species. Michigan limnologists Pullman and Crawford (2010) have suggested that rapidly proliferating starry stonewort “may be one of greatest challenges ever faced by management professionals and lake user groups in Michigan.”
Starry stonewort frequently produces dense monotypic meadows that have been commonly observed in Michigan inland lakes extending from near shore areas in depths of less than one meter to the outer most edges of the littoral zone in depths of up to nine meters, completely engulfing the most sensitive and productive of areas within colonized inland lakes. Aquatic meadows of invasive starry stonewort form dense benthic barriers of up to two meters thick that effectively prevent the growth of an important array of native submerged aquatic plants that rely upon access to bottom sediments for vertical stability and for the uptake of nutrients. In colonized inland lakes, it is not uncommon to observe littoral areas that once supported diverse plant communities now entirely dominated by vast starry stonewort meadows and completely devoid of native submerged aquatic plants. Dense monotypic aquatic meadows possess the ability to significantly alter and/or destroy submerged native macrophyte communities. Native submerged macrophytes play a vital role in inland lake ecosystems by reinforcing and exerting influence on several vital physical, biological and chemical mechanisms that contribute to sediment stability, water transparency, moderate biological productivity levels and the promotion and sustainability of plant and animal biodiversity. Severe degradation and/or loss of native submerged macrophyte communities represent a significant threat to the immense ecological, recreational and economic value of Michigan’s inland lakes.
The evidence that starry stonewort has now successfully colonized several hundred Michigan inland lakes continues to mount. It is extremely important that lakefront property owners, recreational boaters, the fishing community and inland lake users in general learn to identify starry stonewort. Early detection and management of the rapidly growing species is critical to sparing your inland lake or favorite fishing spot from the ecological ravages of this unprecedented biological invasion.
To learn more about invasive starry stonewort and its impact on Michigan’s inland lakes, please plan on attending the 2014 Michigan Inland Lakes Convention which will be held on May 1st, 2nd and 3rd at the Boyne Mountain Resort in Boyne Falls, Michigan. To find out more about the first ever lakes convention, visit http://michiganlakes.msue.msu.edu/convention .
Michigan Lake and Stream Associations is proud of the fact that we have conducted fifty two consecutive annual conferences. However, in order to promote and support the broad interests of our various collaborative partners, the previously scheduled venue and dates for our 2014 annual conference have been integrated within the overall concept of a first ever Michigan Inland Lakes Convention.
Michigan Inland Lakes Convention
Thursday, Friday and Saturday, May 1 – 3, 2014
Boyne Mountain Resort in Boyne Falls, Michigan
Conducted under the auspices of the Michigan Inland Lakes Partnership, an initiative created in 2008 to promote collaboration to advance stewardship of Michigan’s inland lakes, several public and private agencies and organizations, including the Michigan Chapter, North American Lake Management Society, the Michigan Department of Environmental Quality, the Michigan Department of Natural Resources, Michigan State University Extension, the Michigan Natural Shoreline Partnership and Michigan Lake and Stream Associations, will join forces to offer two and one half days of inland lakes focused open sessions, workshops and a wide array of topic specific breakout sessions designed to appeal to a wide range of personal and professional interests.
Activities traditionally associated with the Michigan Lake and Stream Associations annual conference such as our annual banquet, our annual review of riparian rights and water law, our awards ceremony, silent auction and the 50-50 raffle will be conducted as usual within the larger context of the overall convention.
Please also note that MiCorps Cooperative Lakes Monitoring Program volunteer monitor training will be held on Thursday, May 1st, 2014 from 9:00 AM to 4:30 PM and on Friday, May 2nd, 2014 from 1:00 to 4:00 PM. Cooperative Lakes Monitoring Program volunteer water quality monitors with questions regarding the 2014 training sessions should contact Ms. Jean Roth, ML&SA CLMP Administrator, at 989.257.3715 or via e-mail at email@example.com .
The inaugural Michigan Inland Lakes Convention promises to be an outstanding opportunity for members of Michigan Lake and Stream Associations and/or readers of The Michigan Riparian to learn more about the science and management of their favorite inland lake and to directly participate in open discussions focused on a number of important inland lake related topics including aquatic invasive species management, riparian rights and water law, preserving or restoring their natural shorelines and working effectively with their local government officials. These are just examples of the many inland lake topics that will be explored over the course of two and one half days at the Michigan Inland Lakes Convention.
For more information regarding the 2014 Michigan Inland Lakes Convention, please read the detailed article regarding the convention which will appear in the Winter 2014 edition of The Michigan Riparian magazine.
To register for the Michigan Inland Lakes Convention, point your browser toward the Michigan Inland Lakes Partnership website at http://michiganlakes.msue.msu.edu .
Save the Date!
Michigan Chapter, North American Lake Management Society Schedules November 1st, 2013 “Lunch and Learn Seminar Luncheon”
Registration is now open to attend the Michigan North American Lake Management Society’s (McNALMS) Fall luncheon. Scheduled for Friday, November 1, 2013 in East Lansing, MI, the luncheon will feature Dr. Ryan Thum from Grand Valley State University’s Annis Water Resources Institute. His talk is titled, “Patterns of Growth, Reproduction, and Herbicide Sensitivity in Natural and Synthetic Populations of Hybrid Watermilfoils.”
An agenda and link to register is available at www.mcnalms.org. The cost is $20 ($15 for full-time students) and includes a buffet luncheon and dessert. You may also register or obtain further information by contacting Lois Wolfson at (517) 353-9222; email:firstname.lastname@example.org. The meeting will be held in the Ottawa Room at the MSU Union on the Michigan State University campus. Travel instructions are available on the registration page.
Zebra mussels have been monitored in Gull Lake (southwestern Michigan) since 1995 by Michigan State University scientists. Massive die-offs of the mussels were observed in Gull Lake in the summers of 2010, 2011 and 2012, coinciding with the warmest water temperatures. However, some other nearby lakes became just as warm but did not have die-offs, and lab studies show that the mussels can tolerate the temperatures experienced in Gull Lake. Given this contradictory evidence, the MSU team is seeking information about similar die-offs that may have been observed in other lakes. Please send your observations to Dr. Stephen Hamilton of Kellogg Biological Station: email email@example.com, phone (269)671-2231. Include the lake name and location (county preferred), what you observed, when it occurred, and how certain you are. We are just as interested in hearing about lakes where no decline has been noticed as those where declines occurred. We appreciate any information you can provide.
The Michigan Department of Environmental Quality (DEQ) is the state regulatory agency responsible for the issuance of permits for various projects that may impact Michigan’s environment. Various divisions within the DEQ issue a wide variety of permits annually as required by state statute and/or based on agency requirements to grant authority to conduct certain activities.
ML&SA members may be interested in searching for and viewing various permits issued to conduct projects on or near coastal areas or inland waterways, including inland lakes and streams. The Coastal and Inland Waters Permit Information System (CIWPIS) is an on‐line resource maintained by the DEQ that allows users to conduct specific searches for permits issued within their area. The system allows searches to be conducted using the date, county, township, name of permit applicant and/or affected waterbody name. The site also allows users to search for and view upcoming public hearings and newly received permit applications. To view the DEQ CIWPIS on‐line system, visit