Monday, July 28, 2014

Will the REAL White Bear Lake problem please stand up?

I was pleased to note this morning that others are raising questions about the Metro Council's options for doing something about the shrinking White Bear Lake. Today Brendon Slotterback, at streets.mn and Net Density, raises some questions that I think are extremely valid and worthwhile. It's a reassuring to have this kind of followup to the My Minnesota post of July 24. In fact, his questions inspired some hypothesizing and admittedly crude analysis. Follow along at your pleasure.

Table 2 from the Council's report

The Metro Council's Northeast Metro Draft Report notes that, for the 16 communities in the White Bear Lake study area, 2010 population is 157,422 with an average day water demand of 18.9 million gallons per day (MGD). After reading that, a quick hop on the Internet seemed in order, over to the MnDNR's web page on water conservation to see what they had to say about:

"Retrofitting

Data from the AWWA indicate that water use could be reduced as much as 33.5 gallons per capita per day (GPCD) by using water-efficient toilets, showerheads, and faucets that meet federal manufacturing standards. The water, wastewater, and energy benefits from replacing inefficient water fixtures should be part of a public education program. It is recommended that communities develop a long-term plan to retrofit public buildings. Retrofitting of public buildings will help promote educational efforts as well as demonstrate fiscal and environmental responsibility."
Unless a handy-dandy spreadsheet, it appears that if the 2010 water use in the 16 communities were reduced by a maximum of 33.5 gallons per day, the gross reduction would be about 5 MGD. (157,422 people X 33.5 GPCD = 5,273,637 GPD or ~ 5 MGD). What makes this number really interesting is that it represents between 25% and 30% of the 2010 average daily consumption, and is almost double the increase in consumption of 3.4 MGD projected for 2030. This entire savings isn't likely to be attainable, but it would go a long way to reducing the size of the problem and probably wouldn't cost 25 % of $600 million or so. If water savings and cost were proportional (I know, they're not) saving 25% of current demand or about 50% of increased demand isn't likely to cost $150 million, I wouldn't think. So where's the analysis of current use and the evaluation of conservation through retrofitting?

At a minimum, one additional question that appears to need exploration is how recent White Bear Lake levels compare to historical information for the entire period of record going back to 1924. Minnesota's DNR has that information on its web site but if you want to review more than the past ten years, say, the entire period of record, you need to down load the available data and use your handy-dandy spreadsheet to create a chart like the one below.

White Bear Lake elevation, source: MnDNR Lake Water Level Report

As I read the chart, White Bear Lake's recent levels have been somewhat below the earliest decade or so of the period of record, but, I assume, back in the 1920's and 1930's, there weren't as many people relying as much on groundwater for their water supply when the lake levels were still in the 920 - 922 range, in comparison with the more recent 919 - 920 range. This isn't to suggest there isn't an issue with White Bear Lake and consumption of groundwater. It does seem to suggest that recent levels aren't entirely without some sort of precedent and that a rigorous analysis of the problem might lead to an entirely different range of alternative solutions. What's the problem we're trying to solve here? Dannie Abse seems to understand.

The Water Diviner

By Dannie Abse 

Late, I have come to a parched land   
doubting my gift, if gift I have,   
the inspiration of water
spilt, swallowed in the sand.

To hear once more water trickle,   
to stand in a stretch of silence
the divining pen twisting in the hand:   
sign of depths alluvial.

Water owns no permanent shape,   
sags, is most itself descending;
now, under the shadow of the idol,   
dry mouth and dry landscape.

No rain falls with a refreshing sound   
to settle tubular in a well,
elliptical in a bowl. No grape
lusciously moulds it round.

Clouds have no constant resemblance   
to anything, blown by a hot wind,   
flying mirages; the blue background,   
light constructions of chance.

To hold back chaos I transformed   
amorphous mass—and fire and cloud—   
so that the agèd gods might dance   
and golden structures form.

I should have built, plain brick on brick,   
a water tower. The sun flies on
arid wastes, barren hells too warm   
and me with a hazel stick!

Rivulets vanished in the dust
long ago, great compositions
vaporized, salt on the tongue so thick   
that drinking, still I thirst.

Repeated desert, recurring drought,   
sometimes hearing water trickle,   
sometimes not, I, by doubting first,   
believe; believing, doubt.


********************************************
Thanks for visiting. Come again when you can.
Please be kind to each other while you can.