Portage Base & Whitewood Owners' Association

 Problems with the Dam

The John Flook Dam began operation in 1966 and for 42 years has been a tremendous asset to this lake community.  In recent years, however, things have changed making the successful operation of the dam a serious challenge.  Briefly, we are getting too much water from upstream contributors making it difficult to maintain a safe winter level and to protect our lakes from serious flooding and shoreline ice damage.  In addition, the age of the dam has resulted in some deterioration of the structures that control the flow of water.  

Background:  At the time the John Flook Dam was built, the Portage, Base & Whitewood Owners Association was known as the Big Portage and Little Portage Lake Property Owners Association. The organization took on the responsibility to request a Special Assessment District (SAD) to be created to build and own the dam.  The dam was finished in 1966 and was designed to maintain the usual lake level of Portage and Base Lakes at 851.54 feet above sea level.  This level was set by Washtenaw County Circuit Court after public input and remains in effect to this day. The dam contains five “Clam Shell” gates which rotate in a curved channel.  These gates can be opened or closed to regulate the flow of water through the dam. As a second part of the project, the Huron River from Base Lake to Bell Road was dredged to eliminate the flooding that had been a recurring problem for the past 100 years.

Winter Operation:  There are many benefits to being able to lower the water level by 12-15 inches during winter.  In addition to preventing ice damage to sea walls and other waterside structures, it also provides a huge reservoir that can absorb springtime flood waters.  From an ecological point of view, it is good for the natural function of the river to be down in winter months as it was before the dam was built.  For the past several years we have been unable to do this and water levels remained high all winter.  

Even during the first winter of operation we discovered that ice would build up on the clam shell channels and the lifting mechanisms used to operate the gates.  This ice developed from the mist created by the water falling over the gates and made operation of the gates impossible.  Attacking the ice with sledge hammers and torches was extremely dangerous and minimally successful.

The current method of regulating the winter level is to put three of the gates in full open position after placing stop logs in vertical channels in front of the gates.  The remaining two gates are used for dumping water downstream when there is a need.  The tops of the stop logs are set to maintain wintertime level 12-15 inches below 851.54.  To add or remove these logs is a manual procedure that requires several people to go out on the metal catwalk across the dam.  If the logs need to be adjusted during freezing weather, this task is both difficult and dangerous.  This method is antiquated and was not the intended purpose of the stop logs.

With the continued urban growth upstream from the dam--more paving, buildings, sewer expansion, and subdivisions--the runoff from all this development sends more and more water into the Huron River.  This increased flow has made it impossible to control the water level in the wintertime.  One reason for this is that we do not have a reliable means of predicting changes in upstream flow.

The Time is Now:  Following the 2004 Memorial Day flooding at Ore Lake, the PBWOA Board began investigating the operation of the dam.  This review led to the conclusion that the time has come to make changes to the dam that will safeguard us from winter ice damage and a possible flood.  The Board has appointed a committee that has been working on this project for the past six months.  The committee has five members: PBWOA secretary Bill Tupper, chairperson; Dave Spielman, past president of PBWOA; George Majoros, Hamburg Township Trustee; Tom Ehman, past president and member of the original association that petitioned for the construction of the dam; Art Stauch, current dam manager; and Dick Knight, local contractor.  The committee has held two joint meetings with both Livingston County and Washtenaw County Drain Commissioners and has determined what improvements will be needed as well as estimates of the costs of those improvements.

New Flow Control Gates:  The first needed improvement is replacement of the five clam shell gates with powered Weir Gates.  These new gates would be vertical operating, twenty feet long and six feet high with double screw lifters powered by electric motors.  The have been proven to operate in extreme cold weather (up to -40°F) and are equipped with sensors that would indicate the exact height at which the gate is set.  These features would allow the dam operator to easily adjust the flow of the river on a moments notice.  The water would always flow under the bottom of the gate from March to November so fish movements would not be impeded (a DNR requirement).

New Flow Sensors:  We also propose to install new flow and water level monitoring systems both up and downstream.  The downstream sensor would measure the exact discharge rate through the dam and the upstream sensors would provide data on the amount of water moving downstream.  This information would take the guesswork out of the operation of the dam and would make dam operation a science based on hard data.  We could become proactive rather than reactive.

By adding the proposed instrumentation and weir gates, the dam can be controlled more quickly and safely to dispense excessive river flow and thus maintain a more consistent 851.54 lake level as well as more constant winter levels.

A Valuable Asset: We have enjoyed 42 years of relatively little costs to maintain the dam, an average $13 per year. The dynamics of the water has changed so much that now is the time to step forward and meet our obligation to maintain the dam to do its intended purpose. The responsibility again falls on those 1400 good property owners like those who stepped forward back in 1964 and wisely decided to do something that would be of great value to our lake property and our enjoyment of this water wonderland.   With what is proposed here, we can achieve a balance in the flow of the Huron River that we have never been able to do before.

Estimated Cost of this Project: The total cost of the project would be divided equality among each property. To replace the Clam Shell Gates with powered Weir Gates, provide instrumentation to monitor the flow of the river to provide better forecasting; we estimate this investment into our own community to in the area that would amount to a yearly cost of $130 to $175 per property. This cost would be spread over 10 years. This would be billed on your township’s tax statement once a year.

 Your Comments are appreciated: You can comment on this proposal via email to PBWOA@charter.net or write to PBWOA 11869 Durston, Pinckney, MI. 48169

The First Dam at Portage

The History of the John Flook Dam and Clare Miller Boat Lock

At our June 2, 2008 meeting of the PBWOA Board;  we asked  Mr. Tom Ehman to give us  his recollection of the history of the Dam and the Special Assessment District that was set up to pay the cost for the Dam and dredging of the river.

Tom’s remarks as taken from the minutes of this meeting:

 John Flook (Portage Dam) History: Introduction of guest Tom Ehman: Bill Tupper explained that Tom was invited to inform the board about the formation of the Special Assessment District that built the John Flook Portage Dam that also included the Clare Miller Boat Lock. Tom explained that the Court order setting the Portage Lake Level of 851.54 was set in February of 1949 in Circuit Court of Washtenaw County by Judge James Breakey and was recorded in September of 1949.

The original lake association, which was called the Big and Little Portage Lakes Association, wanted to do something about the flooding because of the 1946 & 1957 severe flooding that occurred those two years.

The B&LPLA wanted to do something about this so they petition the court to set the level at 851.54. The association was represented by its President Marshall Guido who was also an attorney. Property owners from Portage Lake were also there and testified that the normal desired level of Portage Lake was this 851.54 feet above sea level. Tom noted that Judge Breakey said in his ruling that this level would be normally maintained at this level.  Normally, was the amount of permitted differential but was not defined. This same process followed for Base Lake several years later. Nothing was done by Washtenaw County to implement the court order so the Portage Lake sailboat racers built a stone dam across the river behind the Trading Post and also at the Portage Launch Site Bridge to try to at least control the summer lake levels. 

Tom went on to explain the details of the how the Portage Dam was built. In 1964 Tom and others submitted petitions signed by owners from Portage and Base Lakes asking the Washtenaw County Board of Supervisors to put a Dam in to control the flooding and to maintain the lake level at 851.54. A member on the Washtenaw County Board of Supervisors and Chair of the Ways & Means Committee Don Silkworth who had a home on Portage Lake that had previously been flooded.  Fortunately, he was really supportive of the project if there was no cost to the county. As it turned out, when Tom was prepared to present a box of petitions to the county, they didn’t even look at them. Tom said that the County Commissioners told the Drain Commissioner, Mr. John Flook to get going on getting the SAD together. But he dragged his feet and nothing was getting done. 

Tom and another association member Pieter Thommasen went into the county and township records and established the level of the highest water mark of the 1946 and 1957 floods that was determined to be 855 feet above sea level. Anyone with property in this floodplain level would be included in the Special Assessment District because it would be a benefit to the owners. There were no complaints about the 855 level or who was included in the SAD. 

Tom went on to say that in 1967, the first winter of operation, we had a January Thaw. The same problem we have now occurred the first year.  Ice had built up on the Clam Gates mechanism so thick that they couldn’t beat it off with a sledge hammer and torches.  The association was afraid that they were going to get sued for the water damages to the cottages around the lake. The Thaw didn’t result in flooding of homes but it did knockout drainfields. The results of this debacle was that they learned that the only way to control the water level in the winter was to first lower the water levels in Portage and Base and then use the stop log method of controlling the water.  

The SAD is still in effect today. The State Statute said and still says the County Board of Supervisors (now the Commissioners) can designate, at their pleasure, which County manages the SAD and operates the Dam.  At the time the dam was built they choose Washtenaw County Drain Commissioner.  Tom reported that the SAD is managed by Washtenaw and Livingston Counties as far as collecting the taxes that went to pay off the costs of building the dam and then collect assessments every year to pay for the cost of maintaining and operation of the Dam. There is no money being pooled for major repairs or replacement of the Dam and most likely there won’t be. Washtenaw is administering the operation and maintenance. The taxing authority runs as long as the dam is there. Tom said that the property owners listed in the SAD own an undivided interest in the John Flook/Portage Dam. 

Costs: Tom said that his recollection is that it was about $250,000 for the Dam with $75,000 in a contingency fund which was used to drill new water wells for the owners downstream on the river who lost their wells because of the lowering of the water table. Also the lower river people where threatening to get an injunction to stop the dam construction because they would be cut off from using the river upstream so quickly a boat lock was designed and incorporated into the project.   So there goes the $75,000. The people still filed legal action and the court ruled that this boat lock was a fair solution for what they really could previously use during real high water. The Boat Lock worked all right but it was very high maintenance because of debris being thrown into it.  

 Question: Who was John Flook? He was the Drain Commissioner for Washtenaw County. The Boat Lock was named after Clair Miller the Drain Commissioner for Livingston County.    

Going Back in History of Flooding 1986

From NOAA Weather Forecast Office

In Michigan, back on September 10, 11, 1986, a slow moving low pressure system moved across the middle portion of Michigan’s Lower Peninsula. In a 24 hour period, the intense rain storm produced rainfall amounts from 8 to 14 inches over an area 60 miles wide and 180 miles long. The 100 year frequency has a 1 % chance of this large of storm occurring in any year. For this region a large storm is about 5 inches in 24 hours.

This storm resulted in thousands of people being evacuated and about 30,000 homes suffered damage. About 3600 miles of roadways were impassable as a result of the failure of four primary bridges and hundreds of secondary bridges. Eleven Dams failed and 19 others were threatened with failure; resulting in 1500 people being evacuated down-stream of the Dams. This storm also resulted in millions of dollars of damaged crops.

A Michigan State hydrologist calculated that if the volume of the rain that fell on the 6200 square miles Saginaw River Basin, an could be laid on top of Lake St. Clair, it would raise the lake 10 feet. The Cass River at Vassar Michigan which has a normal level of 4.5 feet and a flood stage 14 feet rose to an unprecedented level of 24.82 feet.

How did this happen? A number of rain events plagued this area leading up to Sept. 10^th & 12^th. 1986. The flooding rain was triggered by a nearly stationary front which, like the flood area itself, stretched east-west across central lower Michigan. Warm moisture laden air from the Gulf of Mexico (enhanced by a moisture plume from the remnants of a tropical system from the Eastern Pacific), streamed north and east out of the mid-west. The upper wind pattern across the Great Lakes was conductive in holding the front nearly in place.   

 Aftermath of the Flood of 1986

 10 people dead

Damage estimated at 400 to 500 Million

22 Counties declared disaster areas

 Flash Floods cause more deaths each year in the United States than lightning, tornados or hurricanes.

PBWOA Directors & Officers 2009/2010