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Attachment 5. Hardcover on Flag-Neck LotsB--Zc CITY OF C HANHASSE N Chanhassen is Community for Life -Providing for Today and Planning forTomorrow TO: Planning Commission FROM: MacKenzie Walters, Assistant Planner DATE: February 7, 2017 #1 ( SUBJECT: Impervious Surface on Flag -Neck Lots Proposed Motion: "The Chanhassen Planning Commission recommends that the City Council adopt the attached ordinance amending Chapters 18 and 20 of the Chanhassen City Code, concerning flag lots." Background: On January 9, 2016 staff presented an issue paper to the City Council informing them that City Code is not clear on how impervious surfaces within flag lots should be treated. In the interest of ensuring consistency and transparency the City Council directed staff to specify how impervious surfaces within these lots should be treated. The Planning Department receives calls from homeowners and contractors asking to clarify if the neck area of flag lots counts towards a lot's area and coverage totals. In cases where the neck area is commensurate with a private street, Section 18-57(p)(8) stipulates that neither the land area nor impervious surface contained within the private street easement are to be included in the lot area or coverage calculations. This same provision also specifies that once the private street ends both the remaining area of the easement and any driveways are to be included in the calculations. In cases where there is no private street, the ordinance is silent. Staff's practice has been to exclude the neck area from coverage calculations. The ordinance does specify in Section 20-615 that the neck area does not count towards the lot's minimum area, but minimum lot area and lot coverage are distinct terms within the ordinance. This ordinance also clarifies that building setbacks shall start at the point that the lot reaches the 100' minimum width stipulated by ordinance but does not define where the neck portion of the lot ends. PH 952.227.1100 • www.ci.chanhassen.mn.us • FX 952.227.1110 7700 MARKET BOULEVARD • PO BOX 147 • CHANHASSEN • MINNESOTA 55317 Planning Commission City Code Amendments — Hard Cover on Flag Lots February 7, 2017 Page 2 of 6 The ordinance's definition of the term flag/neck lot, found in Section 1-2, mandates that these lots have a 30' neck in order to be classified as a flag lot. The City has numerous non- conforming lots that do not have the required 30' neck. It is unclear if these lots should be treated as flag/neck lots or standard lots. Examples: Address Lot Size with neck (sq. ft.) Neck Width (ft.) HC including neck HC Lot size minus neck HC minus neck Max HC 7604 South Shore Dr 19,602 26 24.5 17,204 21.8 25 7331 Minnewashta PKY* 46,204 55 28 38,561 24.9 25 7351 Minnewashta PKY* 44,866 30 28.9 34,852 22.2 25 3301 Shore Dr 188,614 60 18.9 180,698 18.9 25 6601 Horseshoe Curve 23,958 40 29.5 18,249 31.4 25 2220 Melody Hill Rd 30,056 34 16 24,071 14.3 25 6311 Church Rd 29,620 32 32 22,620 20 25 4158 Lakeridge Rd 59,241 28 19.8 53,941 17.9 25 1352Ithilien 17,424 30 27.1 15,257 24.8 25 1392 Ithilien 14,810 30 31.3 13,725 32.3 25 1385Ithilien 23,086 30 1 20.3 20,804 18 25 Note: These coverage calculations are approximations from aerials. *Part of this is likely a private road. Uncertain where road ends and driveway begins. Relevant Ordinances: Section 1-2: Requires neck to be at least 30' wide to meet definition of flag/neck lot.* Section 18-57(p)(8): Neither the land area in private street easement or nor its impervious surface are included in the lot area or lot coverage calculation; however, once the private street ends the area of its easement and the driveway are included. Planning Commission City Code Amendments — Hard Cover on Flag Lots February 7, 2017 Page 3 of 6 Section 18-57(R)(1-3): Stipulates the conditions under which a variance for the creation of new flag lots maybe allowed. Specifically, they must be necessitated by prevailing development patterns, a public or private street system must be unnecessary, and/or it will serve to protect the natural environment. Section 20-615: Sets lot requirements for neck or flag lots as 15,000 sq. ft. excluding the neck, front lot width of 100' at building setback line, and front yard setback shall be measured from the point where the lot achieves 100'. The code does not define where the neck ends, only were the lot setback should be measured from.** Section 20-1122(1): Neck or flag lots are exempted from normal driveway setbacks. Starting at 20' from the front property line driveways may be setback a minimum of 5' from the side property line or the distance of an existing drainage and utility easement. Section 20-1122(8): Allows the City Engineer to approve reduced driveway setbacks for neck or flag lots. *The ordinance was amended to require to 30' minimum width in 1990. "Staff s practice has been to consider the neck to end at the point where the lot achieves 100'. Analysis: Issue: Should land area and impervious surface on necks be included or excluded from coverage calculations? Discussion: Excluding the land area and impervious surface on necks would be consistent with how private streets, which serve a similar function, are treated and with how lot area is calculated. Including the land and impervious surface areas in coverage calculation would likely generate numerous variance requests as homeowners argued the unique shape of their parcel created a hardship and unreasonably low amounts of useable lot area. The shape of the parcel would only be considered a hardship in cases where the flag lot itself is not a variance, i.e. nonconforming lots created before March 26, 1990 (definition adopted). Issue: Where does the neck end for the purpose of lot coverage calculations? Discussion: On flag lots that follow the stipulated 30'+ neck with parallel lot lines that connects to a rectangular lot with a 100'+ width it is visually clear where the neck ends; however, many lots do not follow this form. For lots where the neck gradually widens, it is not clear where the neck ends and the lot begins. This is especially relevant for properties where the driveway within the expanding neck widens beyond what is necessary for access to the property. This can result in large amounts of impervious surface being excluded from lot coverage calculations. Issue: Neck lots usually have levels of impervious surface well above the 25% normally allowed in RSF districts. Discussion: The amount of impervious surface on a property has substantial implications for stormwater management. The City engineers its stormwater management systems to handle the Planning Commission City Code Amendments — Hard Cover on Flag Lots February 7, 2017 Page 4 of 6 runoff generated by single family homes with up to 25% hard cover. The neck area of flag lots almost always exceeds that threshold. For example, even a 10' driveway on a regulation 30' neck means that a portion of the property will have 33 % lot coverage. The code currently accommodates a 20' driveway within a 30' neck which results in 66% lot coverage. On lots where the neck widens beyond the 30' minimum a homeowner could theoretically build a wider driveway with an even higher ratio of impermeable to permeable surface. In the most extreme case a homeowner could build a 50' driveway in a 60' neck creating 83.3% lot coverage within the neck. The amount of stormwater generated by these parts of a property can be substantial as necks are often over 100' long. It may be advisable to include the neck lot's predicted impact on the lot's stormwater generation as part of the variance criteria used to evaluate requests to create flag lots. The maximum width of driveways within a lot's neck should also be stipulated. Issue: If flag lots' impervious surfaces are not included with the properties' coverage calculations, how should that impervious surface be accounted for? Discussion: As discussed above, the neck areas of neck/flag lots can involve large amounts of impervious surface and create stormwater management issues. It is important to have accurate projections of a subdivisions total imperious surface in order to effectively manage stormwater. A potential solution could be to stipulate a maximum 33% driveway width for the length of the neck and include that total in the tabulation of the subdivision's streets and other impervious surfaces. Issue: There are numerous parcels of the neck/flag lot type that do not meet the ordinance's definition of a flag lot because they have a neck that is less than 30' wide. Should they be treated as flag lots or normal lots? Discussion: Either way these lots will be non -conforming lots; however, it may make sense to formally grandfather them in as flag lots. This would provide consistent treatment of parcels with similar features. Treating them as normal lots would create all of the complications listed above with including the neck's area in impervious surface calculations. Alternatives: 1) Do nothing. Staff's current practice of excluding the necks and impervious surface within necks from coverage calculations seems in line with the intent of the ordinance. However, this may lead to underestimating the amount of hardcover in the City. 2) Amend the relevant sections of the City Code to clarify how necks are to be incorporated or omitted from coverage calculations and how much impervious surface they are allowed. This would help make sure that all properties are held to the same standard, that homeowners and developers understand how much impervious surface they have to work with on a parcel, allow the City to more effectively manage the amount of impervious surface present, and require stormwater management with the neck area unless it is included in the street stormwater system. Planning Commission City Code Amendments — Hard Cover on Flag Lots February 7, 2017 Page 5 of 6 Staff recommends alternative two because it adds clarity and transparency to the City's lot coverage calculations, allows us to account for all impervious surface within the City, and allows for better management of the City's stormwater. Recommendation: Staff recommends the following changes be made to the City code. Section 1-2 Lot, flag/neck means a lot that does not provide the full required frontage on a public right-of-way, but rather is served by a narrow "neck" of land that extends to the street. To meet the definition the neck must be at least 30 feet wide. The lot width on neck of flag lots and lots accessed by private streets shall be 100 feet as measured at the front building setback line. Lots of this type existing before March 26, 1990 shall be classified as neck/flag lots for the purposes of determining lot area, lot coverage, and front yard setbacks even if they do not meet the stipulated neck width. The location of these lots is conceptually illustrated below. (18, 20) NeW Flag Lots Frort Lot Line Street I I � I I I � Lot Wcth 100' J � Lt Wnith I I Section 18-57(r) (4) Sufficient open space is preserved or other provisions are made to offset the increased percentage of hardcover that will be contained within the neck portion of the lots. Planning Commission City Code Amendments — Hard Cover on Flag Lots February 7, 2017 Page 6 of 6 Section 20-615 (5) The maximum lot coverage for all structures and paved surfaces is 25 percent. For neck/flag lots neither the area within the neck, nor the impervious surface of the driveway within the neck shall be included within the calculation of the lot area or lot coverage of the lot. Section 20-1122 (6) For A-2, PUD -R for single-family detached houses, RR, RSF, R-4 and RLM for single-family detached residential uses, the width of the driveway access shall not exceed 24 feet at the right-of-way line. No portion of the right-of-way may be paved except that portion used for the driveway. Inside the property line of the site, the maximum driveway width shall not exceed 50 feet. The minimum driveway width shall not be less than ten feet. For flag/neck lots the impervious surface of the driveway access within the neck portion of neck/flag lots shall not exceed 33 percent of the neck's area. Attachments 1. Full text of cited City Ordinances. 2. Ideal Flag Lot 3. Typical Flag 4. Flag with Widening Drive 5. Percentage of Hard Cover of Neck 6. Draft Ordinance G:\PLAN\City Code\2017\2017-02 Various\Flag Lots\Report HC on Flag -Neck lots Attachment 1: Full text of cited City Ordinances Sec. 1-2. - Rules of construction and definitions. • Lot, flag/neck means a lot that does not provide the full required frontage on a public right-of-way, but rather is served by a narrow "neck" of land that extends to the street. To meet the definition the neck must be at least 30 feet wide. The lot width on neck or flag lots and lots accessed by private streets shall be 100 feet as measured at the front building setback line. The location of these lots is conceptually illustrated below. (18, 20) Lot We th 100' Necki Flag Lots Front Lct Line Lr_it tAWth Sec. 18-57. - Streets. (p) Private street standards. If the use of a private street is to be allowed, it shall be subject to the following standards: (8) Private streets serving residential development with a density equal to or greater than four units per acre, commercial, office, office industrial, or mixed-use districts, must be located within a strip of property at least 40 feet wide extending out to the public right-of-way or covered by a 40 -foot wide easement that is permanently recorded over all benefited and impacted parcels. Neither the area within the easement for the private street, nor the impervious surface of the 1 private street shall be included within the calculation of the lot area or lot coverage of the lot in which the easement is located. Once the private street terminates, the area of the easement and impervious surface of the driveway shall be included in the calculation of lot area and lot coverage for the lot. Sec. 20-615. - Lot requirements and setbacks. The following minimum requirements shall be observed in an "RSP District subject to additional requirements, exceptions and modifications set forth in this chapter and chanter 18: (1) The minimum lot area is 15,000 square feet. For neck or flag lots, the lot area requirements shall be met after the area contained within the "neck" has been excluded from consideration. (2) The minimum lot frontage is 90 feet, except that lots fronting on a cul-de-sac "bubble" shall be 90 feet in width at the building setback line. The location of this lot is conceptually illustrated below. Fronta¢e Measured at Setback Line (3) The minimum lot depth is 125 feet. (4) Lot width on neck or flag lots and lots accessed by private streets shall be 100 feet as measured at the front building setback line. The location of these lots is conceptually illustrated below. NECK/FLAG LOTS FRONT LOT LINE STREET 100' LOT WEDTH I LOT l I WMTH i Neck/Flae Lots (5) The maximum lot coverage for all structures and paved surfaces is 25 percent. (6) The setbacks are as follows: a. For front yards, 30 feet. b. For rear yards, 30 feet. c. For side yards, ten feet. (7) The setbacks for lots served by private streets and/or neck lots are as follows: a. For front yard, 30 feet. The front yard shall be the lot line nearest the public right-of-way that provides access to the parcel. The rear yard lot line is to be located opposite from the front lot line with the remaining exposures treated as side lot lines. On neck lots the front yard setback shall be measured at the point nearest the front lot line where the lot achieves a 100 -foot minimum width. b. For rear yards, 30 feet. c. For side yards, ten feet. (8) The maximum height is as follows: a. For the principal structure, three stories/35 feet. b. For accessory structures, 20 feet. M Sec. 20-1122. - Access and driveways. The purpose of this section is to provide minimum design criteria, setback and slope standards for vehicular use. The intent is to reduce interference with drainage and utility easements by providing setback standards; reduce erosion by requiring a hard surface for all driveways; to limit the number of driveway access points to public streets and to direct drainage toward the street via establishment of minimum driveway slope standards. Parking and loading spaces shall have proper access from a public right-of-way. The number and width of access drives shall be located to minimize traffic congestion and abnormal traffic hazard. All driveways shall meet the following criteria: (1) Driveways shall be setback at least ten feet from the side property lines, except on lots that access off of a cul-de-sac "bubble", neck or flag lot where the lot frontage may prohibit meeting the side yard setback requirement. Beginning 20 feet from the front property line, driveways may be setback a minimum of five feet from the side property line or the distance of the existing drainage and utility easement on the particular lot or parcel. Encroachment into a side yard drainage and utility easement must be reviewed and approved by the city and may require an encroachment agreement. (8) Driveway setbacks may be reduced subject to approval by the city engineer and the following criteria: a. The driveway will not interfere with any existing drainage swale or easement in which a utility is contained; b. Shall require an easement encroachment agreement from the engineering department; c. The driveway must be designed to maintain stormwater drainage ranoff on the property to ensure that it will not cause runoff onto adjacent properties; d. Snow storage may not be placed on adjacent properties; and e. Lot frontage on lots that access off of a cul-de-sac "bubble", neck or flag lot do not permit adequate driveway access width or side yard setback. co Y _0 tko 10 LL N Y m LL Ln 0 0 J M O J N O J Attachment 3: Typical Flag v`etvay ivgmeck . s0 VA Chanhassen, MetroGIS, Carver, Henne A - . Attachwent 4: Flag with Widening Drive A A* a d O z 0 V 5 0 c a v a m `o r a V 0 v ro m o u m IR o IR x is �c eo v O N y N N Q M N O Z a V N Ip l0 O Z w J Q a 0 U ? � U � � m O m ` N V L eQi eNi eri a a 3 0 N w N O 0 L Y t0 to W VI 3 3 v a Y � V � y J 0 0 Z Q ` J O O O O L M Q m M a o 3 v z z Y W V d Z ti ti o Z > > J V 'u m v U s a a a c o N v w Y v o v v O M O O O M O M m m M E E o o V a m V N d a J U � � O 0 a 0 N N O L z 3 3 a 0 0 ` J `m `m o z z ti ti o > > m CC N O M O O E E o o o 0 0 0 0 0 0 3 3 c 3 3 c c a o 0 3 z z v a a m m o m m e a m o N oo Ic .. M m o -I N .-� 00 Q m Y Q Q Q ei N 4l1 M Q rl M Q M N Q M N d W O Z MVZv "—o Mor mm o m wo OO MN MN.+ 0 .� �O w mM m N N .� O V N v > m m CN O �O Q Q M N O O O N O r. O V L rl m 'i M N H 'i rl N N rl ei rl ei ei `w a a 3 v v w 0 0p M Q N vt O O r V1 N O a0 O1 N r w N r O O vt r N N e-1 N M .i r Q M Q Y L U N N J Z Q tD v1 O O Q N 0p O O O Q Q O 0 0 L N V1 M lO M M N M M M Q N m M M a 3 v y W V N Z Y Y > > p d 2 ¢ _ p _ p N N vOi t H H _ a j w v W v M N K m i 0° O o o u u` L t a v o ` Q C c `p d O d s _ '_ _ C C a 0 49 d VI V1 Q rl N ei O .i O] N N Y1 O Yf O ei Q O �o M mr V1 mr O m N NN m .y N O� W Q N VI m m m m r m TM �o 4 Q .+ .. .. �c �o Q w o0 Attachment 6 Section 1-2 Lot, flag/neck means a lot that does not provide the full required frontage on a public right-of-way, but rather is served by a narrow "neck" of land that extends to the street. To meet the definition the neck must be at least 30 feet wide. The lot width on neck or flag lots and lots accessed by private streets shall be 100 feet as measured at the front building setback line. Lots of this type existing before April 4, 1990 shall be classified as neck/flag lots for the purposes of determining lot area, lot coverage, and front yard setbacks even if they do not meet the stipulated neck width. The location of these lots is conceptually illustrated below. (18, 20) NeokIFW9 Lots Front Lot Line street I I I I I I I Lot Nitllh 100' I LdVV&hI i I I Section 18-57(r) (4) Sufficient open space is preserved or other provisions are made to offset the increased percentage of hardcover that will be contained within the neck portion of the lots. Section 20-615 (5) The maximum lot coverage for all structures and paved surfaces is 25 percent. For neck/flag lots neither the area within the neck, nor the impervious surface of the driveway within the neck shall be included within the calculation of the lot area or lot coverage of the lot. Section 20-1122 (6) For A-2, PUD -R for single-family detached houses, RR, RSF, R-4 and RLM for single-family detached residential uses, the width of the driveway access shall not exceed 24 feet at the right-of-way line. For flag/neck lots the impervious surface of the driveway access within the neck portion of neck/flag lots shall not exceed 33 percent of the neck's area. No portion of the right-of-way may be paved except that portion used for the driveway. Inside the property line of the site, the maximum driveway width shall not exceed 50 feet. The minimum driveway width shall not be less than ten feet. CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE NO. ]insert number] AN ORDINANCE AMENDING CHAPTER 20 CHANHASSEN CITY CODE, ZONING, CONCERNING GENERAL SUPPLEMENTAL REGULATIONS THE CITY COUNCIL OF THE CITY OF CHANHASSEN ORDAINS: Section 1. Section 1-2 of the Chanhassen City Code is amended to read as follows: Lot, flag/neck means a lot that does not provide the full required frontage on a public right-of-way, but rather is served by a narrow "neck" of land that extends to the street. To meet the definition the neck must be at least 30 feet wide. The lot width on neck or flag lots and lots accessed by private streets shall be 100 feet as measured at the front building setback line. Lots of this type existing before March 26, 1990 shall be classified as neck/flag lots for the purposes of determining lot area, lot coverage, and front yard setbacks even if they do not meet the stipulated neck width. The location of these lots is conceptually illustrated below. (18, 20) Lot %A th 1O(Y. teckffft Lata Frord Lot Lira may' LL aWfthI I Section 2. The Chanhassen City Code is amended by adding section 18-57(r)(4) to read follows: (4) Sufficient open space is preserved or other provisions are made to offset the increased percentage of hardcover that will be contained within the neck portion of the lots. Section 3. Section 20-615(5) of the Chanhassen City Code is amended to read as follows: (5) The maximum lot coverage for all structures and paved surfaces is 25 percent. For neck/flag lots neither the area within the neck, nor the impervious surface of the driveway within the neck shall be included within the calculation of the lot area or lot coverage of the lot. Section 4. Section 20-1122(6) of the Chanhassen City Code is amended to read as follows: (6) For A-2, PUD -R for single-family detached houses, RR, RSF, R-4 and RLM for single-family detached residential uses, the width of the driveway access shall not exceed 24 feet at the right-of-way line. No portion of the right-of-way may be paved except that portion used for the driveway. Inside the property line of the site, the maximum driveway width shall not exceed 50 feet. The minimum driveway width shall not be less than ten feet. For flag/neck lots the impervious surface of the driveway access within the neck portion of neck/flag lots shall not exceed 33 percent of the neck's area. Section5. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this [insert date] by the City Council of the City of Chanhassen, Minnesota Todd Gerhardt, City Manager Denny Laufenburger, Mayor (Published in the Chanhassen Villager on [insert date])