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6.15 ,---c, Iit / A A 14 - Item# 6. 15. y of . � MEMORANDUM Lik Ri• ver TO: Planning Commission FROM: Stephen Wensman, Planner DATE: March 23, 1999 SUBJECT: Ordinance Amendment to create an Open Space Preservation Development Overlay Zoning District and Regulations Request The City of Elk River request that the Planning Commission review the proposed Ordinance Amendment to create an Open Space Preservation Development Overlay District and Regulations. Attachments III • Open Space Preservation Development District Regulations Overview The Open Space Preservation Development District Regulations are written to permit clustering of detached single family residential units as an overlay district in the Rla (Rural Residential District) and A1(Agricultural Conservation) zones if the development meets the minimum requirements. The overlay district shall be administered similarly to the Antenna Tower districts or the Mineral Excavation districts. Staff has solicited comments from developers and the MN Land Trust. The City Attorney has not yet commented on the Ordinance Amendment. Issues To create incentives and lessen the disincentives of the OSPD. Some examples include: 1. Base park dedication requirements on the Yield Plan rather than actual with bonuses. III 13065 Orono Parkway • P.O. Box 490 • Elk River,MN 55330 • TDD &Phone: (612) 441-7420 • Fax: (612)441-7425 Memo to Planning Commission/OA 98-3 March 23, 1999 Page 2 • 2. Consider additional standards to allow density bonuses: a) Tree preservation b) Provide storm-water treatment that exceeds City and State standards c) Utilize septic systems preferred by the City 3. Conservation Easement Holders Several developers were against having the MN Land Trust as the easement holders, and preferred Homeowners Associations. The greatest criticism made of the MN Land Trust was their strict open space criteria. The MN Land Trust requires 50% of the buildable land be set aside as open space with conservation easements over them, rather than 50% gross area as Sherburne County requires. This criteria could prove to be a disincentive to developers and force conventional development on lands with unique natural features worthy of saving. On the other hand, Homeowners Associations may be less willing to enforce the conservation easements on neighbors, or the organization might break down over time leaving the City with the responsibility. • Request Staff requests that the Planning Commission review and make final recommendations regarding an Ordinance Amendment to create an Open Space Development Overlay District and Ordinance Amendment • \\elkriver\sys\shrdoc\planning\stevewen\pcmmo\oa98-3pc.doc FEATURE INFORMATION • Growing Greener: . . CONSERVATION ubdivision regulations are SUBDIVISION DESIGN These areas should be pre-identified on a one of the principal tools for by Randall Arendt community-wide map of potential con- shaping our communities. It is servation lands in the comprehensive through the subdivision review process plan (see page 11) so that each new that communities most directlyassure ' , ti – KK development will add to — rather than that residential development is designed ,-, p,4,:-} r 4.;,, ,wy `: subtract from— the community's open in a way which promotes community 1 ; • space acreage. objectives such as the preservation of Another result is that conservation space and natural areas. - subdivisions make it easier for munici- openBut to back up a step,why should we i� �� palities to implement community-wide be concerned about protectingopen �`� u a �F. n r*t-, , , `< �"b'* greenway plans, which may depend on �i developers to provide critical links along space? In a nutshell, by preserving open 4 • r ,? space we protect streams and water '"`� �� particular stream valleys or hilltop quality, provide habitat for plants and ` `A ^.?.. : C ridges. animals, preserve rural "atmosphere," ` On the following pages you'll learn provide recreational areas, protect home M 4= - more about conservation subdivision values,and reduce costs of municipal ser- s �t,& tz:y ,` design, and how this approach might vices. In short, land conservation makes " `,- -'4 as benefit your efforts to plan for a more our communities better places to live. :11w� :,•,:;- ` p_ . ' liveable community. As you will see on the followinP r,. s; g r ,r._L ��, ,,:�+ , 1 Hamburg Township,Livingston County es, the conservation subdivision ,f. r °' ' ppsmall, continued on page 8 roach involves but significant, changes to the subdivision design and design. This should not be surprising. Editor's Note:On the following pages, review process. When integrated with Homebuyer surveys show that people excerpts from Randall Arendt's Model comprehensive plan and zoning provi- strongly desire open space, recreation Ordinance Provisions for Conservation sions which encourage the preservation areas,and scenic views. See pages 8-9 for Subdivision Design are set out,along with of open space, a community can—over more on this. discussion of nine key issues—including a period of years—protect an intercon- Conservation subdivision design dif- the"economics"of conservation subdivi- nected network of conservation lands. fers in several significant ways from the sions.As a planning commissioner I've Developers can easily become the com- more familiar "cluster development" found it is often helpful in understanding munity's leading conservationists,as each approach. Under conservation design how a proposal really works to see it in new subdivision adds another link to an principles (as you will see in the model ordinance form.In reading through the area-wide open space system.One Michi- ordinance), full density is achievable model ordinance note,in particular,how gan community' has, in fact, conserved only when at least 50 percent of poten- the focus is on identifying land to be con- more than 1,000 acres through this tially buildable land is set aside. This served before moving on to locate house approach in the Iasi-eight years,a conser- compares with cluster provisions that sites and streets. vation value of at least$10 million! frequently require only 25 to 30 percent Our thanks to Island Press for allow It is critical to realize that conserva- of the gross land area to be conserved. ing us to excerpt from the Model Onii- tion subdivision design is not only fair to Moreover, with cluster development this nance,which appeared in Arendt's Conservation Design for Subdivisions developers,it actually enhances the value open space is often comprised of left (Island Press,1996).Note also that Island of development. Studies comparing over,undesirable areas such as stormwa- Press will be publishing Arendt's Growing developments built according to conser- ter management facilities or land under Greener Workbook this Autumn.It will vation design principles with those fol- high-tension power lines. contain illustrated case studies,and much ing more conventional, land- Although clustering has produced a additional material.For information on sumptive, layouts show that houses few small "green islands"here and there, either publication,call Island Press at: tend to sell faster and real estate values conservation design can protect blocks 800-828-1302. appreciate more with conservation and corridors of permanent open space. PLANNING COMMISSIONERS JOURNAL / NUMBER 33 / WINTER 1 9 9 9 PM MODEL ORDINANCE that would otherwise be buildable under local,state and federal regulations,so that .,y; Y f k ' - PROVISIONS FOR their development potential is not reduced t s • , • - I. CONSERVATION by this designation.Such density credit may `. t: r be applied to other unconstrained parts of � ": � �, 0BDIVISION DESIGN the site. • «' k. ,,,It 1 • s`� ...The locations of Secondary Conserva- MINIMUM a MINIMUM PERCENTAGE tion Areas shall be guided by the maps and f' '.4- -" e �i'� ;`'.421, ' '� 4.' OF OPEN SPACE policies contained in the Open Space, * ormi .,t . "` , { 1r The minimum percentage of land that Recreation,and Environmental Resources r • . ° • 1-;I l',.: '1'1" ,4•:,......v.4:*-,,,,` shall be designated as permanent open Element of the comprehensive plan,and Mown trail through open space.Stillmeadow space,not to be further subdivided,and shall include all or part of the following development.Waukesha County,Wisconsin. protected through a conservation ease- kinds of resources:mature woodlands, ment... aquifer recharge areas,areas with highly *Are conservation A minimum of fifty percent(50%)of the permeable("excessively drained")soil,sig- subdivision regulations total tract area,after deducting the follow- nificant wildlife habitat areas,sites listed on fair to developers? ing kinds of unbuildable land... the [state natural areas inventory],prime Conservation Design rearranges the wetlands...floodway and floodway fringe farmland,historic,archaeological or cultur- development on each parcel as it is within the 100-year floodplain...land with al features listed(or eligible to be listed)on being planned so that half(or more) of slopes exceeding 25%,or soils subject to national,state or county registers or inven- the buildable land is set aside as open slumping...land required for street rights- tones,and scenic views into the property of-way(10%)of the net tract area)...land from existing public roads.Secondary Con- space.Without controversial"down under permanent easement prohibiting servation Areas therefore typically consist of zoning," the same number of homes future development... upland forest,meadows,pastures,and farm can be built in a less land-consumptive LOCATION OF OPEN SPACE fields,part of the ecologically connected manner,allowing the balance of the matrix of natural areas significant for property to be permanently protected The location of open space conserved wildlife habitat,water quality protection, and added to an interconnected net- through compact residential development and other reasons.Although the resource work of community green spaces.This shall be consistent with the policies con- lands listed as potential Secondary Conser- "density-neutral" approach provides a tained in the Open Space,Recreation,and vation Areas may comprise more than half fair and equitable way to balance con- Wonmental Resources Element of the of the remaining land on a development servation and development objectives. rehensive plan,and with the recom- parcel(after Primary Conservation Areas Conservation zoningis fundamen- mendations contained in this section and have been deducted),no applicant shall be I the following section("Evaluation Criteria"). required to designate more than 50%of that tally fair because it allows landowners I Open space shall be comprised of two remaining land as a Secondary Conserva- -c ,;Ps n• r'I types of land:"Primary Conservation tion Area. i Areas"and"Secondary Conservation , :,,-V,1 )1E. r �,,,�., •' ' r EVALUATION CRITERIA l i Areas."All lands within both Primary and �' �+ .` ! ` Secondary Areas are required to be protect- In evaluating the layout of lots and open ,� —t ! • '4 ps i ~-'r�V ed bya permanent conservation easement, space,the following criteria will be consid- ir `� 1. :%,d.'• 0 i r '� prohibiting further development,and set- ered by the Planning Commission as indi- �, ` s `�► ' = ti.�' P g ting other standards safeguarding the site's eating design appropriate to the site's i'' L ' f y ?•� '�L! i special resources from negative changes. natural,historic,and cultural features,and ;'...X.>] i- + ] meeting the purposes of this ordinance. �'' 1.Primary Conservation Areas. :1'•; i, t Diversity and originality in lot layout shall r 4.---,I-; - am 17 • This category consists of wetlands,lands be encouraged to achieve the best possible s ' --'* * ' '- that are generally inundated(under ponds, relationship between development and con- a it , — -_ lakes,creeks,etc.),land within the 100-year servation areas.Accordingly,the Planning ''gl .. ; .: floodplain,slopes exceeding 25%,and soils Commission shall evaluate proposals to Alir. •" a� . _� subject to slumping.These sensitive lands determine whether the proposed conceptu- fi ar . are deducted from the total parcel acreage al preliminary plan: to produce the"Adjusted Tract Acreage,"on 1.Protects and preserves all floodplain, . which density shall be based wetlands,and steep slopes from clearing, , I.2.Secondary Conservation Areas. grading,filling,or construction(except as In addition to the Primary Conservation may be approved by the governing body for i "". 40,at least fifty percent(50%)of the essential infrastructure or active or passive „ fling land shall be designated and recreation amenities). permanently protected.Full density credit 2.Preserves and maintains mature Tot lot in Garnet Oaks development.Bethel shall be allowed for land in this category continued on page 10 Township,Delaware County,Pennsylvania PLANNING COMMISSIONERS JOURNAL / NUMBER 3 3 / WINTER 1 9 9 9 and developers to achieve full density parts of the site are within the open value 13 percent more over a 20 year under the municipality's current space conservation area. period than the conventionally zoning. The second advantage occurs dur- designed subdivision(which had much Although conservation zoning pre- ing marketing and sales,when devel- larger individual houselots,but little cl>,full-density layouts that do not opers and realtors can capitalize on the community open space).2 coWe open space,this is legal amenities that have been preserved or In conservation subdivisions with because there is no constitutional provided within the development. substantial open space,there is little or "right to sprawl." These positive features can form the no correlation between lot size and Second,no land is taken for public basis for an environmentally-oriented price.These developments have some- use. None of the land which is required marketing strategy highlighting the times been described as"golf course to be designated for conservation pur- benefits of living in a community communities without the golf course," ' poses becomes public (or even publicly where forest habitat,meadows,wet- underscoring the idea that a house on a accessible) unless the landowner or land buffers,and/or productive farm- small lot with a great view is frequently developer wants it to be. In the vast land has been preserved. worth as much or more than the same majority of situations,municipalities A national survey of homebuyers house on a larger lot which is boxed in themselves have no desire to own and conducted in 1994 by American Lives on all sides by other houses. manage such conservation land,which revealed that of 39 features critical to - they generally feel should be a neigh- their choice,homebuyers ranked"lots ii, ,. / borhood responsibility. of natural open space" and plenty of i"�,� I, A • ,, , ,x 11 The "economics" of "walking and biking paths" as the third 1),: F % ,,«, and fourth highest rated factors affect- ;` �' Y �; conservation subdivisions " The first advantage of conservation ing their`decisions.' subdivision design is the opportunity it The`art of marketing conserva- tion subdivisions emphasizes that buy- offers to reduce infrastructure engi- . ers of smaller lots are actually neering and construction costs. purchasing much more than their indi- Because the development pattern is p g Ponds at Woodward development.Kennett vidual lots.With open space ranging Township,Chester County,Pennsylvania. more compact,street and utility costs from 50 to 65 percent,sales strategies araced. In addition,conservation focusing on this kind of amenity strike *Wildlife design can reduce the number of costly a responsive chord among many home- management benefits wetland crossings needed,since those buyers,particularlywhen lots are laid Y Conservation biologists tell us that �ia, •. a. ,' ,rte; out to maximize views of the conserva- tion riparian woodlands along rivers,' land. creeks,and streams offer our best hope °' When the conservation area abuts for creating a system of interconnect- er it ' a.,` 'r' `` other similar land,as in the communi- ing corridors for a variety of wildlife— ir tt;,1-". r1 � . ty-wide open space network,a further from aquatic organisms and fish to V. Y�•t �,, I ;, marketing advantage exists. amphibians and small terrestrial main- ' # t i mals (such as raccoons,muskrats,and 0 r.R - ©How do residential values ,, Lo otters)—that link the aquatic system � ' in conservation subdivisions j 1" „."� } e--•-*^�:, - to the adjoining upland. l Jam:. ' compare t0 conventional Natural areas preserved in conser- ,.._� 111 . - , ",,,- .-,_-- ;� subdivisions? vation subdivisions provide important D. - ...�a+=a 4' :...',.. "-,-,,,,....:4+4.....;; Homes in conservation subdivi- habitat for wildlife to dwell in and tray- , • ` wz"`* :• .- sions tend to appreciate in value faster el through.The greenways that are one than their counterparts in conventional of the hallmarks of conservation sub- develop . ::,i.., developments.A fairly long-term study ' division design provide cover and comparing two Amherst,Massachu- naturally selected corridors for various - setts,subdivisions built at about the species to move through,as they travel same time,with very similar homes that originally sold for almost the same 1 See page 5 for citation b " price,found that homes in the"open ( space"subdivision(which included 2 Jeff Lacy,"An Examination of Market Apprecia- tion for Clustered Housing With Permanent Open more woodlands,meadows,and trails, Space."Center for Rural Massachusetts 1990.For but smaller house lots) appreciated in information,call:413-545-2612. PLANNING COMMISSIONERS JOURNAL / NUMBER 33 / WINTER 1 9 9 9 MI woodlands,existing fields,pastures,meadows, 13.Includes a pedestrian circulation system Figure 1. The conservation lands(shown and orchards,and creates sufficient buffer designed to assure that pedestrians can in gray)were deliberately laid areas to minimize conflicts between resi- walk safely and easily on the site,between out to fonn part of an inter- dential and agricultural uses.... connected network of /I g properties and activities or special features • 3.If development must be located on open within the neighborhood open space sys- open space in these V fields or pastures because of greater con- tern.All roadside footpaths should connect three adjoining P/ :� P subdivisions. °/ a / f straints in all other parts of the site,dwellings with off-road trails,which in turn should �� - / should be sited on the least prime agricul- • A / link with potential �` gp t nnal o ens ace on adjoining � /.� ,� P P J g . � � •a j - tural soils,or in locations at the far edge of undeveloped parcels(or with existing open 4 '''5•t:' •Zei' -a °'a %r a field,as seen from existing public roads.... space on adjoining developed parcel,where v 4,4 4 ne' . q( 4.Maintains or creates an upland buffer of applicable). �d na " 4 t �9i0,a �j�.a.) natural native species vegetation of at least 14.Provides open space that is reasonably r a o'Q �_` " �/ Q aa�� o Q 100 feet in depth adjacent to wetlands and contiguous.For example,fragmentation of Q : surface waters,including creeks,streams, open space should be minimized so that ° a • ,'. \ti od.n � q,--springs,lakes,and ponds. these resource areas are not divided into Ca ' „ 5.Designs around existing hedgerows and numerous small parcels located in various r.. Ise •• treelines between fields or meadows,and mini- parts of the development. 1,4 4 mires impacts on large woodlands(greater ELEMENTS OF THE �' " than five acres),especially those containing PRELIMINARY PLAN PROCESS many mature trees or a significant wildlife from their nests and burrows to their habitat,or those not degraded by invasive 1.Pre-Application Discussion. vines.Also,woodlands of any size on high- feeding places or hunting grounds. A pre-application discussion is strongly In addition ly erodible soils with slopes greater than conservation subdivi- ly encouraged between the applicant,the site sions can include areas managed as 10%should be avoided.However,wood- designer(s),and the Planning Commission. lands in poor condition with limited man- The purpose of this informal meeting is to wildlife or wildflower meadows. agement potential can provide suitable introduce the applicant and the site design- locations for residential development. ... ®Community map of er(s)to the zoning and subdivision regula- potential conservation lands 6.Leaves scenic views and vistas unblocked potential conservation lands tions and procedures,and to discuss the or uninterrupted,particularly as seen from applicant's objectives in relation to the offi Although many communities have public thoroughfares.... cial policies and ordinance requirements.... adopted either Comprehensive Plans • 7.Avoids siting new construction onor Open Space Plans containing prominent hilltops or ridges,by taking 2.Existing Resources (Site Analysis)Plan. detailed inventories of their natural advantage of lower topographic features. Plans analyzing each site's special features and historic resources,very few have 8.Protects wildlife habitat areas of species are required for all proposed subdivisions, taken the next logical step of pulling listed as endangered,threatened,or of spe- as they form the basis of the design process cial concern... for greenway lands,house locations,street 9.Designs around and preserves sites of his- alignments,and lot lines.The applicant or toric,archaeological,or cultural value,and his/her representative shall bring a copy of their environs,insofar as needed to safe- the Existing Resources(Site Analysis)Plan guard the character of the feature,including to the on-site walkabout.Detailed require- stone walls,spring houses,barn founda- ments for Existing Resources(Site Analysis) tions,cellar holes,earthworks,and burial Plans are contained in another section ok.f ,,. grounds. this ordinance,but at the minimum must ' ' r ' 10.Protects rural roadside character and include: `( ~ , improves public safety and vehicular carry- (1)a contour map based at least upon topo- WIC 4 .-" ; Ns . i r rd — ing capacity by avoiding development graphical maps published by the U.S.Geo- ,: x� c!,ttit1/4.. fronting directly onto existing public roads. logical Survey; r , . ` , i Establishes buffer zones along the scenic (2)the location of severely constraining ele- , r'','1.4%:...`` °°'.' i�. -_ u� corridor of rural roads with historic build- ments such as steep slopes(over 25%),wet- W •.r'" 1 ,:-...%,A,-,$,' •; planning documents. The next task is to identify two kinds of resource areas. R.4„i, "', -....„ 1-1,4.0',.-14-. -, f 's •Primary Conservation Areas comprise - ,,..'.-L ---..`',.s , t X. ,. r.,,.. 7 . only the most severely constrained , � is• tt��*4 'at „ rt,.>p t t lands,where development is typically k ak , >144' , ” i , ,, �., restricted under current codes and laws ti & 1 A 3 Al .,44..„,�� 4._� , , i dr �� n�, ,..o•vo,,!.�•!•1. �V f- (such as wetlands, floodplains,and �t � �` � 3 ��`''Z7 /:d L'��- � '}, Y j74". Yea _-.•,•11.16,,,,g6„,.:i i4 /., ����/� slopes exceeding 25%). Secondary �' �: �� " ;�� Conservation Areas include all other ` � ' ,b La_° .,. e,4 �'� %� � locally noteworthy or significant dont o C� y y g scan[fea es backing onto open space.Prairie Crossing development.Grayslake,Lake Count Illinois. os,Q a` % are/ tures of the natural or cultural land P y y scape—such as mature woodlands, wildlife habitats and travel corridors, sheds). It will also reveal gaps where prime farmland,groundwater recharge no features appear. areas,greenways and trails,river and Although this exercise is not an stream corridors,historic sites and exact science,it frequently helps local k, buildings,and scenic viewsheds. These officials and residents visualize how Secondary Conservation Areas are various kinds of resource areas are con- together all that information and creat- often best understood by the local resi nected to one another,and enables ing a Map of Potential Conservation them to tentatively identify both broad dents who may be directly involved in Lands. their identification. Usually these swaths and narrow corridors of Such a map is vitally important to resource land that could be protected any community interested in consery in a variety of ways. ing an interconnected network of open - Not surprisingly, the most im or- x_ cam . P space. The map serves as the tool a _ tant step in designing a conservation which guides decisions regarding � subdivision is to identify the land that which land to protect in order for the v is to be preserved. By using the corn- which to eventually take form and � ' ` �; 4: munity-wide Map of Potential Conser- e substance. d ' -t ,, --. �, vation Lands as a template for the A Map of Potential Conservation irk ` rat's, Lands starts with information con- '4.>z°�.�r- )"_" . , e;: . . layout thin newsubdivisions, theseldevel areas tamed in the community's existing View from hill.Ponds at Woodward development. opments help to create an intercon- Kennett Township,Chester County,Pennsylvania. nected network of open space spanning the entire municipality. resource areas are totally unprotected � , � � Figure 1 shows how the open space , and are simply zoned for one kind of in three adjoining subdivisions has �. 4 in or another. . � �_ been designed to connect,and illus- � �� s . Abase map is then prepared on trates the way in which the Map of t,_•,46;-••,L=1.‘�'I 6 • ..i which the Primary Conservation Areas v _ t o ' - x r Potential Conservation Lands can r have been added to an inventory ofy .--:1.---":, -1,, become a reality. ' ' ' i _, lands which are already protected A .,, (such as parks,land trust preserves, Stormwater management - x ) tr i and properties under conservation & Water unlit • ' _ ' -. , easement). Clear acetate sheets show Conservation subdivision design g ° -, ', ` i. -, ; . ._- ing each kind of Secondary Conserva- offers a more effective and less costly {rtiv",- �,,�:'�`''`"• ,� tion Area are then laid on top of the approach to stonnwater management ..� , r :' ',,: base map in an order reflecting the than conventional subdivision layout. �, ' - �'` community's preservation priorities This is because conservation design (as determined through public causes less disturbance to the subdivi- ' discussion). sion parcel as a whole (leaving a i, r ,� This overlay process will reveal cer greater percentage of woodlands and t - - fain situations where two or more con meadows in their natural state),pro- "" servation features appear together viding larger areas of natural vegetation (such as woodlands and wildlife habi- that act as buffers to help filter tats,or farmland and scenic view- stormwater. PLANNING COMMISSIONERS JOURNAL / NUMBER 33 / WINTER 1999 r z:r„'ri meadows,scenic views into or out from the to designing subdivisions,described below, ;;:.: t' property,watershed divides and drainage could be applied to the subject property.Ati', c >, t;, ways,fences or stone walls,rock outcrops, the discretion of the Planning Commission k. ..,...::41.1,,....‘ ° ' and existing structures,roads,tracks and this conference may be combined with the �'��;'� ` trails... on-site walkabout. These Existing Resources(Site Analysis) 5.Conceptual Preliminary Plan. � S Plans shall identify both the Primary Con- servation Areas(floodplains,wetlands,and After the pre submission conference,a z ._ sketch plan or a Conceptual Preliminary steep slopes,and Secondary Conservation Plan shall be submitted for all proposed ~ Areas...The Existing Resources(Site K subdivisions.As used in this ordinance,the ,y.�- = Analysis)Plan shall form the basis for the �- �--, � � .%� 4 term"Conceptual Preliminary Plan'refers \ conceptual Preliminary Plan,which shall - '..•::-.4' ....-j• "*"` . to a preliminarily engineered sketch plan show the tentative location of houses, •, "4,N.‹.-, drawn to illustrate initial thoughts about a - ,�„: - j' - streets,lot lines,and greenway lands in new \ t- =.� fF subdivisions,according to the four-step conceptual layout for greenway lands, ,,, i . \ • ,* s r•, .,� - house sites,and street alignments.This is t design process described below the stage where drawings are tentatively - ''.f.'-:::".-.'''''it`. • 3.On-Site Walkabout. + �' illustrated,before heavy engineering costs After the Existing Resources(Site Analy- are incurred in the design of any proposed • sis)Plan has been prepared,the Planning subdivision layout.... -. S-• Commission shall schedule a mutually con- A Conceptual Preliminary Plan shall be venient date to walk the property with the submitted by the applicant to the zoning Reducing runoff velocity allows applicant and his/her site designer.The pur- officer who will then submit it to the Plan- stormwater to be absorbed into the soil pose of this visit is to familiarize local offi- ping Commission for review for the pur- and be taken up by the vegetation. cials with the property's special features,and pose of securing early agreement on the Buffers also offer important infiltration to provide them an informal opportunity to overall pattern of streets,houselots,Primary and"recharge"benefits because they offer guidance(or at least a response)to the and Secondary Conservation Areas,and help maintain adequate flows of fil- applicant regarding the tentative location of potential trail linkages(where applicable), the SecondaryConservation Areas and the tered water to underground aquifers. prior to any significant expenditure on er Aquifer replenishment is essential for potential house locations and street align- engineering costs in the design of streets, q •ments.If this visit is not scheduled before stormwater management,or the accurate maintaining stream flow during dry ubmission of the sketch plan or the Con- delineation of internal lot boundaries.... summer months,which is,in turn, ceptual Preliminary Plan,it should occur 6.Four-step Process. necessary for the health of aquatic soon thereafter. habitats. Each sketch plan or Conceptual Plan 4.Pre-Submission Conference. Although the groundwater impact of shall follow a four-step design process,as Prior to the submission of the sketch plan described below(See Figure 2 below) an individual development may not be or a Conceptual Preliminary Plan,the appli- a.Designating the Open Space.During the terribly significant,the cumulative effect cant shall meet with the Planning Commis- of hundreds of acres of native woodland sion to discuss how the four-step approach continued on page 14 and meadows being evenly graded and o ix 200 Fr - 0m11....1200 Foil CO 200 F. _ nr� t i - wren 2. Inm p r�.`.: — —�� Nor — ® / _` — norm �. �— g` branl.nd ]p' J ,rte ® —1 4., `". T /� I a r red ' " 3 I l mr dw I Q 4----- O ml rwrr \\ / wrrrap ? '(\ v 41r1� s .q.w wod, mraw • / ! u ''''''M ' I \> I .red Medseror *7 \1 ` ' eO / '' � 1 --4. aaranl.nd \1� -: 40 --N.. '' '.'1.1 I— fi steep.lope greeter than 2e% 100 year floodpleln Figure 2.The Four-Step Process.Step 1,Part One. Step 1,Part Two.Identifying Secondary Step 1,Part Three.Identifying Potential Identifying Primary Conservation Areas Conservation Areas Development Areas PLANNING COMMISSIONERS JOURNAL / NUMBER 33 / WINTER 1999 - .AA "spray irrigation,"and "wastewater the most sense. xw. reclamation and reuse." These terms • Individual Landowner describe variations of a well-document- , At its simplest level, the original ed technology that is superior to con- landowner(a farmer, for example) can ventional mechanical systems in many retain ownership to as much as 80 per _ !,?.• ` \ ways because they produce only very cent of the conservation land to keep it F r-: ; small amounts of sludge by-products i, F.. in the family. (At least 20 percent of the '_� - , and help to replenish local aquifers. open space should be reserved for \? ., , ti� 'l ,. With spray irrigation,wastewater is i 1 heavily aerated in deep lagoons where common neighborhood use by subdivi- sion residents.) That landowner can • Vit receives a "secondary" level of treat ' ,, also pass this property on to sons or ' r mens similar to that provided by con-`+� daughters,or sell it to other individual a ventional sewage plants. Itis then `�? - landowners,with permanent conserva- tion easements runningwith the land '�' % sistent with the soil's natural absorp- and and protecting it from development tion capacity.A growing number of under future owners. The open space environmentally sensitive golf courses are irrigated and fertilized with waste- should not,however,be divided among all of the individual subdivision lots as Creek and meadow.Ranch at Roaring Fork. water treated in this way.The practice land management and access difficul- Garfield County,Colorado. has been well accepted by golfers and g nearby residents because it is safe, covered with streets,driveways,patios, ties are likely to arise. rooftops,and lawns(which allow for a odorless, •and environmentally sound. • Homeowners Associations surprisingly high amount of runoff) can Although the conservation design Most conservation land within sub- be very considerable. makes it easier to use land treatment divisions is owned and managed by By reducing the overall area of systems,a conservation subdivision homeowners'associations(HOAs).A can,of course,be served by conven- few basic ground rules encourage a impervious surfaces and suburban lawns that would otherwise be created, tional sewage plants,individual good performance record. First,mem- likservation design reduces the total septic systems,or community septic bership must be automatic,a precondi- ume of stormwater runoff. systems. tion of property purchase in the Who will own and maintain development.Second,zoning should O Sewage Treatment require that bylaws give such associa- theConservation subdivisions offer conservation land. tions the legal right to place liens on greater opportunities to implement Ownership Choices. properties of members who fail to pay environmentally sensitive sewage treat- There are basically four options, their dues. Third,facilities should be ment and disposal systems,known which may be combined within the minimal(ball fields and trails rather alternatively as"land treatment," same subdivision where that makes than clubhouses and swimming pools) 0 00 200 Feet . ,......7 0 00 200 Feel, _. 0 100 200 Feet/' NOrM 7� - Np11� �- - q 4-'!„, • p, '4 ."-.\`-'.' ' ‘'''1,,-4,:ii 1 1-1 0 , --/ ' 'z, � 1 O / ta ./ a. O/ / G/ / a� i OD � J871 'c am.. e•>., { 0 -1 O .1 -` µql/ r \ \ !I its 1_\ ' i'Y- O�\'i ❑- Elj I'1 ! I O ti ❑ a� � Yw�, O,'_ O l� 'I': I 1111 Step 2.Locating House Sites Step 3.Aligning Streets and Trails Step 4.Drawing in the Lot Lines PLANNING COMMISSIONERS JOURNAL / NUMBER 33 / WINTER 1 9 9 9 first step,all potential conservation areas --` .,...-z43p,,, , r ,v��t}, '�t't :;r tit , ,s w -• '0 'fit 1,' ' 'i , , y, r. ` ;, :1 .. Y4� (both primary and secondary)are identified, ., , r, using the Existing Resources(Site Analysis) ".., <4x' ; `" , i y4` ` '` ;'• Plan.Primary Conservation Areas shall w ok -..t.,•• ;!•;,.';'...1•::‘,:",' 'y _" ^� .,.i a itIrl consist of wetlands,floodplain,slopes over fio.�� t �~� c ;W i .-Tv,,, \:• ,and soils susceptible to slumping.Sec- _ - ,, % ' "�s P , ,� k. ,-. ,> ry Conservation Areas shall comprise ¢ "' 's',' r 50%of the remaining land,and shall y ' g'�a;:° '' '., � '`3•, ;-+ • 15._ include the most sensitive and noteworthy , 1 ''i'.••,',<„�s '.'{ ;�:" s " • a natural,scenic,and cultural resources on 3 7 ,>:*. i y' ." ' that remaining half of the property ,- • Guidance on which parts of the remain- ±4:.'",• ,$j •.-12::-;: ':�.; t S t,.in� --'. '"Vj�` � ing land to classify as Secondary Conservara' . ...-•, ,., tion Areas shall be based upon: r, •k. ,,"• ' • F•-:• �"`�' , " •44 • �i * • the procedures described in Conservation ..f4. b Design for Subdivisions... s y '-‘a'... •on-site visits or"walkabouts" 1,, . L"_ 1- ;, °a "'1 ��` �. 7*,f ' •the open space locational criteria •the evaluation criteria •information from published data and Trail sign.Garnet Oaks development.Bethel Township,Delaware County,Pennsylvania. reports,and •conversations with existing or recent to keep annual dues low.And fourth, conservation land within a new subdi- owners of the property,and members of the detailed maintenance plans for conser- vision,such as when that land has planning commission. vation areas should be required-by the been identified in a municipal open b.Location of House Sites.During the sec- municipality as a condition of space plan as a good location for a and step,potential house sites are tentative- approval. The municipality has neighborhood park or for a link in a ly located.Because the proposed location of houses within each lot represents a signifi- enforcement rights and may place a community trail network. Developers cant decision with potential impacts on the lien on the property should the HOA can be encouraged to sell or donate ability of the development to meet the 14 fail to perform their obligations to certain acreage to municipalities uation criteria,subdivision applicants4 maintain the conservation land. through additional density incentives, l identify tentative house sites on the • Land Trusts although the final decision would Conceptual Preliminary Plan and proposed Although homeowners'associa- house the developer's. house sites on the detailed Final Plan. tions are generally the most logical Maintenance Issues. House sites should generally be located not Local officials should require con- closer than 100 feet from Primary Conser- vation recipients of conservation land within vation Areas,but may be situated within 50 subdivisions,occasionally situations servation area management plans to be feet of Secondary Conservation Areas,in arise where such ownership most submitted and approved prior to grant- order to enjoy views of the latter without appropriately resides with a land trust ing final subdivision approval. • negatively impacting the former.... (such as when a particularly rare or c.Street and Lot Layout.The third step significant natural area is involved). Randall Arendt is a consists of aligning proposed streets to pro- Land trusts are private,charitable land use planner, site vide vehicular access to each house in the designer, author, lecturer, groups whose principal purpose is to i most reasonable and economical way.When protect land under its stewardship and advocate of conser- r lots and access streets are laid out,they vation planning. He is ,--./. from inappropriate change. Their most / shall be located in a way that avoids or at vice president of conser- � : i� • least minimizes adverse impacts on both common role is to hold easements or vation at the Natural the Primary and Secondary Conservation fee simple title on conservation lands Lands Trust in Media :. within new developments and else- Pennsylvania.Arendt is ` Areas.To the greatest extent practicable, p y •- wetland crossings and streets traversing where in the community,to ensure that the principal author of Rural by Design:Main- existing slopes over 15%shall be strongly all restrictions are observed. To cover taining Small Town Character (APA Planners discouraged.Street connections shall gener- their costs in maintaining land they Press,1994),and authored"Open Space Zoning: ally be encouraged to minimize the number own or in monitoring land they hold What It Is&Why It Works,"in PCJ#5(1992). of new cul-de-sacs to be maintained by the easements on,land trusts typically If you have any questions, you can contact township and to facilitate easy access to and Arendt at:Natural Lands Trust, 1031 Palmers require some endowment funding. from homes in different parts of the proper- Mill Rd., Media, PA 19063; 610-353-5587. Wnd on adjoining parcels).... •Municipality or Other Public Agency More details on the Growing Greener approach Lot Lines.The fourth step is simply to In special situations a local govern- outlined in this article can be found at the Natur- draw in the lot lines(where applicable)....• ment might desire to own part of the al Lands Trust web site:www.natlands.org PLANNING COMMISSIONERS JOURNAL / NUMBER 33 / WINTER 1 9 9 9 IR