05-28-1991 Council Packet - Laserfiche WebLink

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The Ice-out Process • — » To explain ic“-out on lakes it is important to Know some ot the ph/si- caJ properties of water. Water is at its .heaviest at 39 degrees and is lighter, at higher and lower temperatures. Al though it is sometimes thought that ice sinks during the spnng thaw, this Is not possible because ice is Nahter than water. Meltwater may accu nu tate on the surface of the ice giving the illusion that the ice is sinking. Ice-^ut begins when ice retreats from the shore and leaves a belt of open --water (with a temperature of 45 .Tndegrees) around the lake. Strong move the remaining ice sl.cfts causing fractures, ice crystals on the edges continue to give up and fall over, melting rapidly in the lake. Eventually the wind will push the remaining honeycombed ice sheet to shore where the rest of it melts. Ice- out should be recorded on the day that 90% of the lake is free of ice. This generally occurs anywhere from late March/early Apnl in southern Min nesota to late April/early May m north ern Minnesota. <» Lakes and Lavvns Spring is here and for many people the first sign of this is green grass. In fact, today there is an obsession among Americans to maintain a well- manicured, green lawn. This results m the use of fertilizers, pesticides and herbicides, which recent studies aiso show as a major contributor to water pollution. It is especially important for people that live on or near a lake to understand the consequences of chemical lawn care and know about available alternatives. Facts on Fertilizers Fertilizers contain the nutrients nitrogen, phosphorous and potash. Whenever fertilizer is applied to a lawn there is a chance that added nutrients will leacn :ntc crcur'owate' or wash into ;ne la^e. 'esu.tmg n oote'* :ia< cnanoes to toe :a-.e tseit Nitrogen ano pncsonorcus reec plants. An increase or eithe' •'uf'en:. esoeciaiiy pnospr'orcus. wm '■esuit -n a sudden growth of jncesirao'e oia"! soecies wnicn can niave several effects • reducec recreational value of t^e lake (boating, swimming). • overgrowth of surface plants resulting in shading and death of submerged plants critical to waterfowl and other aauatic animais. • an increase m dead oiant material wmcn uses up oxygen ounng decay The lower oxygen level may cause the lake to be taken over oy rougn fisn • reduced water clanty from in creased algae blooms: • diminisning amount of snorelme All of the aoove contribute to dimin ished watenront prooeny values. Alternative methods of lawn care The first question everyone needs to ask IS "How much lawn ao l really need?". There are several benefits to preserving the natural vegetation of the area. Natural vegetation can control erosion very effectively and act as a filter for water running towards the lake (there should always be a foot or so left before the shore i Secondly, plants native to the area orovide food ano cover for wildlife soecies including nesting waterfowl. Once the size of the lawn is decided upon (if one is needed), there are several non-chemical methods of caring for it which will enhance its appearance and longevity without polluting the lake. • Grow grasses that do well m your locality (i.e.. grow fo; acidic soil 0(^0 •rQOQ ' , ^ ^ rr» 3 .' »r y«»j •>sj9 9 . w season amount of ramfail. etc. • ‘.ever mow mors than one mc.n off at a time • Jse nutrient-'"cn lake wate' to .vaier the -awn. • '.Vatcn your 'awn carefully and catch proDiems oetore they oecome too oig. Learn to tolerate a tew weeds. • Acd "natural orcamc fertilizers such as comoost material, blood meal ana mixfjres available at your local nursery. A comoost pile IS an effective method of adding nutrients to your lawn and diSDCSing of household food waste. The comoosted material can be aoDiied as a too dressing for lawns and '■aked m. However, don t put a comoost pile close to shore or burn prusn and leaves on a slope where the asnes and nutrients can wash into the iar,e If fertilizing is necessary Before deciding to fertilize, every lanoowner snould nave their soil tested. In many cases, fertilizing will not make a difference to the health of ycu' 'awn or you may find that only cedain nutrients need to be added. To reduce the harmful effects of nutrient runoff vvhen fertilizing: • Do not apply fertilizer when the crass IS wet. during high winds, heavy rams or if any rainfall is predicted. • Use non-phosphorous fertilizer When possible. Studies have Shown that lawns rarely need phosphorous. Contact local nurseries and if possible, make a non-phosphorous brand available through your lake association. • Follow the directions. Never apply more fertilizer than is necessary. Use a calibrated spreader or spot apply. Understanding Your Lake is published as a membership pene* i toi Freshwater Pounoanon uaxe Organization mempers. Lake Organization member benefits include: lake management publi cations, publication discounts and participation m lake surveys ano lake monitoring programs. Readers are encouraged to reproduce and distribute any portion ot Unaeistanamg Your Laxe: prior permission not reouired Please contact the Freshwater Foundation for more information about Lake Organization memoersnips or lake management programs Editor Margaret Robensen Freshwater Foundation, p 'o.'box 90. Naverre. MN 55392-0090. (612) 471-6407. FAX: (612) 471-6142 L