Is agriculture the easy target in TDML debates? 05/14/12 2:27:12 PM
Ask John Jacobs, veteran Renville County drainage specialist if agriculture is the easy target in TDML discussions and he responds, "They look at the land mass. They ask what segment represents the largest land mass. They ask who are the largest users of the water sheds within a drainage basin. Quick and easy the fingers point at agriculture even though turbidity in rivers might have various culprits."
He's not saying information relative to implement Total Daily Maxium Loads for sediments into the Minnesota River and its tributaries is weighted unfairly against agriculture. He simply maintains that 'scientific data' needs to be identified first and then 'common sense' logic as to logical procedures for the entire eco system need to be agreed upon.
He's a proponent of pattern tile systems for most farmland. That would be expected since his firm does miles and miles of pattern tiling each year. But he knows that a well planned drainage system produces cleaner water into the total drainage basin and much less erosion of sediment-enriched topsoils. He also knows that a huge world population needs at least a 50 percent increase in food production to meet the 9 billion population projected by 2050.
Explains Jacobs, "We don't get nearly the flass-flood runoffs from fields that are pattern tiled because the entire field acts as a sponge. With that entire rain storm soaked up by the soil mass above the tile system, water is siphoned off in a slow, controlled manner. Also soil is a great filter so there are fewer sediments including phohphorous, nitrates and other potentially hazardous materials getting into drainage ditchs and streams and rivers. The net result is much less turbidity."
He thinks that with a well-planned system, surface intakes can pretty much be eliminated across the farming landscape. He reminds that every Minnesota county now has soil surveys depicting any and all soil types. By using the Minnesota drainage guide you can look up your particular soil type, or types, and this guide will suggest what depth and what spacing are needed to drain a particular coefficient. "Most of our county systems are designed to a 3/8ths inch coefficient. And that simply means they'll take 3'8ths of an inch of water off an acre in 24 hours."
So look at the soil types you have and the permeability of each soil and that determines the depth and spacing you'll need to reach a particular drainage coefficient.
Are the turbidity concerns of the Minnesota River realistic in terms of being doable? Jacobs says muddy rivers are not a recent problem and in no way relate to the huge amount of pattern tiling in the Minnesota landscape. He remembers his granddad saying that when the settlers first came up the Minnesota River they described the watr as being too thick to make good coffee and too thin to plow!
"It doesn't mean we shouldn't explore ways to reduce turbidity of the Minnesota Rive but if the ultimate goal is geting it down to zero, we'll never get there. But he believes new TMDL standards being suggested are reasonable. "From what I've seen I believe we can attain them," summed up Jacobs.
The Minnesota River Basis is big encompassing roughly 15,000 square miles and contains all or parts of 37 Minnesota counties.