Lake Hiawatha Water Management

The Minneapolis Park and Recreation Board (MPRB) recently published background documents on water management issues at Lake Hiawatha and Hiawatha Golf Course that have guided priority-setting and decison-making for the past two years. I would encourage everyone with an interest in the subject to have a look at the papers in the “What’s New” tab at the bottom of the linked page. For many of those most involved in the issue, this review of the project may be redundant, but for many others it will establish a useful starting point for discussion. Even for experts, these documents may provide a good review of the analysis and evaluations upon which park board staff have relied.

What I have not found in those otherwise useful briefings was a recap of historical events to put water levels in perspective. So….here goes. Let’s turn the clock back again. (For more background on the creation of Lake Hiawatha and the adjacent Hiawatha Golf Course and some cool “before” photos, read my recent post Troublesome Lake Hiawatha.)

Lake Depth

Theodore Wirth’s initial plan for dredging Lake Hiawatha was to dredge to a depth of 14 feet. Due to budget concerns, however, he had reduced his dredging plan to a depth of ten feet when contracts were let. In his 1929 annual report (dated January 1, 1930), he wrote that ten feet “as called for in the present contract is the very minimum depth a lake should be, and the only reason for specifying such a minimum depth was to keep the cost…down.” He added, however, that due to money saved through a very competitive bidding process, “it is my earnest recommendation that it be increased to fourteen feet.” His argument was twofold: one, it would produce a “cleaner” sheet of water with less vegetation; two, it would bring the land area to a “higher and more desirable grade at a reasonable cost of $35,000.” That additional four feet of dredging, he noted the next year, had produced an additional 270,000 cubic yards of material.

By the time grading of the new golf course was done, Wirth wrote in his 1932 report that a low lake level and favorable weather had “permitted the creation of much more undulation than hoped for in the great area of level land devoted to the golf course…with the happy result that the eighteen holes will be a more interesting course than it was anticipated could be made.” Had more extensive grading also produced more low areas that could eventually flood?

Lake Level

The lake level used as the average in the contemporary water management study reached via the link at the top of this post is 812.8 ft MSL or above mean sea level. The measurement of levels has changed a few times in the last century. The water levels cited in park board reports from its beginning in 1883 through the time Lake Hiawatha was dredged were in feet above “city datum.” Never mind what that means for a moment. In his 1931 annual report Wirth gives a “normal” elevation of Lake Hiawatha as 100 city datum. To translate city datum measures to contemporary MSL measures requires the addition of roughly 710 ft to the city datum. (If a geodesist finds that I’m off, please let me know a better translation.)

Yikes! That means today’s “normal” of 812.8 ft. MSL is nearly three feet above normal in Wirth’s time of about 810 ft MSL.  Take three feet of water off Lake Hiawatha today and most of the golf course and all surrounding neighborhood basements are dry.

But wait, there’s more!

Although 100 was considered the normal level for Lake Hiawatha in 1931 the actual water level that year—the year dredging was finished in a very dry year—was only 96.25! In today’s terms that would be about 806.25 ft MSL, or six-and-a-half feet, roughly one Kawhi Leonard, below today’s normal!

Wirth provided this data in a section of his 1932 report that explained how the park board had contracted with the city to pump city water into the lakes to raise levels. In 1931 the park board paid the city $1,422.25 to pump 113,780,090 gallons of city water into Lake Hiawatha to raise its level to 98.62 ft or roughly 208.62 ft MSL, still four feet below today’s normal! The same year the park board paid the city $3,071.09 to pump 245,687,400 gallons into the Chain of Lakes (Cedar, Isles and Calhoun) and $1,201.19 to pump 96,095,580 gallons into Nokomis.

Why did they do it? Wirth’s words:

“As an experiment to find out definitely how practical and at what cost it would be feasible to raise our lake levels during dry periods, and in order to have the appearance of our lakes in presentable condition for the Knights Templar Conclave in June, together with a desire to have the bathing beaches at certain lakes made available for use…It will be difficult to operate our Lake Calhoun and Lake Nokomis bath houses efficiently with the present elevation of water.”

While noting that given the board’s finances it would be difficult to find the funds to pump water into the lakes in 1933, the Great Depression was grinding people and landscapes to dust, Wirth estimated it would cost $21,762.50 to pump the 1.741 billion gallons of water needed to raise the lakes to normal elevations. (Precision was one of Wirth’s strong suits—as was his compulsion to make his parks “presentable”.) That money was not forthcoming from the park board’s budget, and that year the situation was the “worst in memory”, Wirth wrote. But water was pumped thanks to the city council which had “come to the rescue”.

Not the End

That beneficence was not, of course, the end of water level problems in Minneapolis lakes. By the mid-1950s the situation was so bad that a pipeline was built from Bassett’s Creek to Brownie Lake to pump water into the lakes and ultimately Minnehaha Creek. Unlike Minnehaha Creek, Basssett’s Creek seldom went completely dry. Even that wasn’t a long-term solution. The park board considered a famous hydrologist’s recommendation in the 1960s to capture water from the air conditioners of downtown office buildings to recycle through the lakes. But the owners of those buildings knew a good idea when they heard one and began recycling their air conditioning water back through their own plants. So the park board eventually built a pipeline from the Mississippi River to the lakes, but that failed too when high phosphate levels in river water threatened lake health. So as you can see, through most of park board history the big challenge was how to raise lake levels, not lower them.

Despite the park board’s ownership of the land fronting on lakes and creeks—one of the marvels of the city—we should keep in mind that the park board cannot manage water tables. Has the park board altered shore lines and creek beds? Absolutely. And anytime that is done there can be unintended consequences that can play out over many years. (“Don’t mess with Mother Nature,” some would say! I am presently writing about one of those decisions that still could have very sad consequences.) But water tables, precipitation and run-off (climate change!) are not within the park board’s control—even when, as at present, park commissioners envision a role for the park board in issues outside the purview of historical park and recreation management. And although I am not a hydrologist, it does not seem logical to me that past park board water-shaping efforts—short of building dams, which they did not do except at Longfellow Lakelet and Shingle Creek—could have been the cause of higher water tables across a wide section of the city.

In my opinion, informed by what I know of the history of the area, the groundwater issue is one for which the park board should not take primary responsibility. I think it demands a broader solution that the city or county and state should address—with input from the park board as a significant stakeholder. Just because the easiest place to dump water from south Minneapolis is into property controlled by the park board (Lake Hiawatha) does not make excess water the park board’s unique problem.

The larger issue in this as in so many issues we wrestle with today is the relative weight of individual interests and collective interests. Striking that balance has always been at the core of the American Experiment. Pursuing that line of thinking, I checked when some of the houses now threatened by high water levels were built. Of all those houses that were actually surveyed for the water management study conducted in 2017 for the park board, only one of 28 was built after 1954 according to Hennepin County property records. Nearly half were built before 1932 when the park board finished dredging Lake Hiawatha. In other words they were built when water levels did not seem to pose a threat.

I hope you will take a closer look at the background information posted by the park board at minneapolisparks.org. I would also encourage you to subscribe to email updates from the park board on the status of plans for Lake Hiawtha and other park areas of interest.

David Carpentier Smith

 

 

 

 

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2 comments so far

  1. JOAN HUNTER PUDVAN on

    Interesting, David…I wish I had a source like you for the area in which I live here. (near Cleveland.) I’m still poking around with postcards…never have seen another “parks” u.s.postal card like the one I sent you. Maybe it’s valuable….don’t throw it away!
    Best, Joan P.

    • David C. Smith on

      Nice to hear from you, Joan. I still have the card you sent. Thanks!


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