Agenda - Planning Commission - 10/06/2016

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i C I SUMMARY OF STATE PROGRAMS Structure setback Impervious Water features Min,width of Minimum width of Restrictions on from water's edge coverage State included protective zone riparian buffer clearing vegetation or buffer limitations ';50'from Limited by 25 Watercourses, 25'.50'for Yes Generally equal to vegetative Georgia tidal waters trout streams trout streams buffer width (same as buffer) requirements Great ponds, saltwater bodies, 75'from streams; Grid and point 20%of lot area Maine rivers,tidal 250'from all other 75' system restricts 75-100 in most districts and freshwater water features clearing wetlands,streams 1,000'from lakes;300' One-half building No"intensive 3 lake classes; Minnesota 6 stream classes (or width of floodplain) setback;50'for clearing"in shore 50-200' 25%of lot area from streams agricultural uses impactzone Water bodies>10Grid and point New 50'for inner ° acres;designated 250'from reference line system used to 50 zo-3 /° o Hampshire rivers, tidal waters waterfront buffer manage clearing Lakes,ponds, 1,000'from lakes;300' Limited clearing; 75'or average Wisconsin flowages,rivers, (or width of floodplain) 35'from ordinary 35'viewing corridor existing setback; 15-30% streams From streams high water mark per loo'of shoreline min.35' loosestrife are unacceptable.Buffers that lack On developed land,the ordinance establishes but its relationship to existing shoreland zon- acceptable vegetation must be planted with a three-zone approach:a 25-foot no distur- ing is not always clear.The law states that the an approved mix of native perennial grasses bance zone,a"structure limit"area extending more restrictive requirements apply,but"more and flowering plants or shrubs,with specific back another 25 feet,and-a transition area in restrictive"is not always immediately obvi- requirements for installation and maintenance. the remaining 5o feet,where most uses at- ous.Moreover,the requirement for"perennial The edges of the buffer strip are marked with towed by the underlying district are permitted. vegetation"could be satisfied by perennial turf a monument at each lot line.The developer is Expansions of existing structures in the first grass,and not the deep-rooted native species responsible for maintenance of the buffer strip two zones is allowed without a variance if the that effectively stabilize streambanks. for five years after installation. setback from the streambank is maintained, The situation is quite different in Wis- although streambank restoration may be re- consin,where environmental and lake as- BUFFERS IN URBAN SETTINGS quired as a condition. sociations charge that the state is rolling back Most of the examples described above are ap- decades of shoreland protection.Changes to plied in rural or suburban settings.In an urban STATE LAWS AFFECT LOCAL REGULATIONS state law in 2015 prohibit local ordinance provi- setting,where most land is already developed, State laws provide a foundation for local regu- sions that are more restrictive than the state's greater flexibility in buffer width and allowed Cation but can also limit its scope.Minnesota's rules(§59.692(id)(a)).Counties that adopted uses may be needed.Some state programs shoreland rules require local governments to higher standards for certain classes of water provide blanket exemptions for more intensely adopt and enforce shoreland ordinances.How- bodies must now roll these back.Among the developed areas.For example,New Hampshire ever,the requirement applies only to selected provisions of the law,local ordinances may not authorizes localities to exempt urbanized water bodies,and studies have shown that require the establishment of a vegetative buffer areas where"vegetative buffers have been only about one-third of the watercourses in the on previously developed land or require expan- depleted,impervious surfaces are in excess of state's agricultural counties were protected sion of an existing buffer,and nonconforming 50 percent,and residential uses are of at least (Rundquist and Cox 2014;Minnesota Board of structures must be allowed to rebuild or re- 10 dwelling units per acre"from state require- Water and Soil Resources 2014). model if the building footprint is not increased. ments 6483-13:12).Maine's shoreland program A new law adopted in 2015 will require an Furthermore,the Department of Natural Re- includes a Commercial Fisheries and Maritime average 50-foot,minimum 30-foot buffer of pe- sources may not issue an opinion on whether Activity District,where the impervious coverage rennial vegetation along all natural watercours- a variance should be granted unless requested limit is 70 percent(Land Rules§1000.15.6.(4)), es and a 16.5 foot buffer along public ditches by a county board of appeals(BOA),and may Salt Lake City's Riparian Corridor Over- managed by drainage authorities(Minnesota not appeal a BOA decision. lay District applies to the major streams that Statutes§103H.48).The law is not linked to cross the city and their associated wetlands local zoning and will be implemented not by lo- RECOMMENDATIONS (§21A.34.130).The ordinance establishes a Cal governments but by each county's soil and Given the diversity of water features and the "no disturbance"corridor of loo feet on un- water conservation district.It will increase the variety of approaches to establishing and man- developed parcels of an acre or more in size. ' number of water bodies protected by buffers, aging riparian buffers,a few best practices can ZONINGPRACTICE 9.16 AMERICAN PLANNING ASSOCIATION[page 6