HomeMy WebLinkAboutA001 - Council Action Form dated July 23, 1991 ITEM #:
DATE: July 23, 1991
COUNCIL ACTION FORM
SUBJECT:
Resolution Approving the Revised Conceptual Development Plan (CDP) for
Prairie West, which is Generally Located South of 24th Street and West of
Prairie View East.
ACTION FORM SUMMARY: This is a request to approve a revised CDP for a .
18 lot subdivision, which is being done in conjunction with a PUD plan
which involves the construction of 90 dwelling units on property
located south of 24th Street, west of Prairie View East and east of
Schilletter Village.
The Planning and Zoning Commission reviewed this request at their
meeting of July 2, 1991 and have no recommendation as two Commissioners
voted for a motion to deny approval, two Commissioners voted against a
motion for denial, and two Commissioners abstained from voting.
The staff recommends approval of this request with the stipulations
stated in this report.
BACKGROUND:
The developer is requesting approval of a revised Conceptual Development
Plan (CDP) for an 18-lot subdivision, which is located south of 24th
Street, west of Prairie View East and east of Schilletter Village. The
proposed subdivision contains a total of 13.58 gross acres and 13.29 net
acres, exclusive of the additional right-of-way for 24th Street. This plan
is a result of City Council action on the PUD plan for Prairie West which
resulted in a decrease in units.
The site is currently vacant and unplatted, and it has been used for
growing crops. There are no mature trees, water courses or significant
topography changes on this site. City staff has researched existence of
wetlands on the site and have found that the Story County Soil Conserva-
tion Service (SCS) has identified an area ( .9 acres) as a "potential
wetland".
Platting is necessary because the original parcel has been split into more
than three parts, and the proposed subdivision will further divide this
property into 18 lots.
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A revised PUD plan has been approved by City Council for this site which
provides for 16 conventional single family lots, which range in size from
10,000 square feet to 13,187 square feet in size; and two multiple family
lots, to accommodate a total of 74 apartment units. These two multiple
family lots contain 3.85 and 3.17 acres.
At the time of City Council approval of the PUD, the Council put a
condition on the single family lots that they be large enough for a home
containing a minimum of 1,500 square feet, and that each home have at
least a two car garage. As a result, the developer withdrew the CDP that
was submitted with the PUD in order to widen the single family lots to
accommodate larger homes.
The revised CDP depicts the new single family lots which have been
widened from 70 foot in width to 80 feet for the rectangular lots on the
east side of Prairie View West, and from 65 feet to 75 feet for the single
family lots in the south side of Prairie View East. Only minor adjustments
have been made to the multiple family lots from the previous CDP submit-
ted to City Council.
ANALYSIS:
Land Use Policy Plan. The existing Land Use Policy Plan (LUPP) desig-
nates this property as suitable for low density residential development.
This designation allows between one (1) and nine (9) dwelling units per
acre. The developer is proposing to develop this site under a PUD plan
with a gross density of 6.63 units/acre and a net density (not including
the 24th Street R.O.W.) of 6.77 units/acre, which is consistent with the
low density designation.
Zoning History. This property was rezoned from R-3 (Medium Density
Residential) to R-2 (Low Density Residential) and R1-6 (Low Density
Residential) on December 11, 1990, by a City Council initiated rezoning.
Prior to that time the south half of this property had been zoned R-3
(Medium Density Residential) since 1965. The north half of the site was
annexed to the City in 1977 and was zoned R-3 (Medium Density Residen-
tial) at that time.
The developers have requested a rezoning to R-2 PUD and R1-6 PUD, to
allow a Planned Unit Development project, which includes low rise apart-
ment buildings and single family detached units. Currently, the first and
second readings of the PUD ordinance have been approved.
Utilities. The utilities available in the area are adequate to serve this
proposed subdivision.
Water. There is an eight-inch water main in Prairie View East which
terminates at the east side of this development. An eight-inch water
main will be extended through this development along the right-of-
way from the Prairie View East terminus to the 12-inch water main in
24th Street, which will result in a looped water system. An inter-
connection will also be made with the 10-inch water main south of the
development.
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Sanitary Sewer. There is an eight-inch sanitary sewer main in
Prairie View East which will be extended through the development
within the right-of-way. All structures will be connected to this
new sanitary sewer main.
Storm Sewer. A storm water management plan has been prepared for
this site which takes into consideration eight watershed areas. New
storm sewer will be extended into the site from the 21-inch storm
sewer in 24th Street. This new storm sewer ranges in size from 21
inches at the north end to 12 inches at the south end of the site.
Electric. There is adequate electric capacity to serve the site, and
the electric utility has reviewed the methods of serving the site and
has approved the plan. A 20-foot utility easement is proposed along
the west side of the site to provide clearance for a high voltage,
overhead power line on adjacent property.
Streets and Vehicular and Pedestrian Access. Access to this development
will be from a new public street, Prairie View West, which intersects with
24th Street on the west side of the project area. This new street will
connect with the existing Prairie View East to form a loop street which will
provide two means of egress for both Prairie View First Addition and this
development. The entire length of the street loop must be completed in
order to be consistent with the requirements in the subdivision ordinance
which states street length should not exceed 1,320 feet without a secon-
dary means of egress.
In order to facilitate traffic movement at the intersection of Prairie View
West with 24th Street, a three lane street approach is planned. There will
be one lane into the development and two lanes out in order to provide
separate lanes for left and right turn movements.
The developer had a traffic impact study done for the first CDP proposal
to determine the impact of traffic from this proposed development on the
quality of flow for existing traffic at the intersection of Prairie View East
and 24th Street, the impact on the quality of flow on 24th Street, and the
effect of additional peak-hour traffic at the intersection of 24th Street and
Stange Road. Since this proposal has a lesser amount of units, the staff
believes the study is still valid, and the traffic impact will actually be less
than previously analyzed. The traffic study concluded that the additional
traffic from the development will not cause a deterioration of flow on 24th
Street. Even during the P.M. peak, which is the highest volume period,
a Level of Service A will be maintained on 24th Street.
This study also reviewed the delays currently experienced at Prairie View
East which are in the acceptable range. It is anticipated that most of the
traffic from Prairie West will use the Prairie View West intersection during
the peak periods studied, thus there should be no significant changes in
delays experienced at Prairie View East.
The intersection of Stange Road and 24th Street was also reviewed. The
greatest impact on that intersection from the Prairie West development
would be from left turning vehicles from 24th Street to Stange Road. The
study concludes that although 20 left turning vehicles would be added to
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this intersection during the A.M. peak hour, the Level of Service wouldn't
be diminished below the current Level of Service D for left turn movement
onto Stange Road.
(To read the report from the Traffic Engineer, see the material attached to
the PUD report.)
Parking has been restricted on the street as part of the proposed
CDP/PUD. No on-street parking is permitted for the north end of Prairie
View West from the single-family lots north. The remainder of this street
will have parking on one side of the street only, which will be on the west
and south sides respectively. This is consistent with the current parking
restrictions on Prairie View East.
An ordinance to this effect must be adopted by the City as part of the
approval of the final plat.
A walkway system will be provided through the site. Sidewalks will run
parallel to both sides of the right-of-way, except along the west side of
Prairie View West north of Lot 20. In addition, an internal walkway
system is planned between the apartment development on Lot 1 and the
east sidewalk along Prairie View West to provide access to the active
recreation area. Sidewalks are also located in front of all the apartment
structures, which lead to the public sidewalks along the right-of-way.
A sidewalk is also planned from this site to the adjacent University
property, which will lead to the Cy-Ride stop in Schilletter Village. The
developers have received permission from the University to construct that
sidewalk.
A bicycle path runs parallel to the south side of 24th Street which serve
this site. It is intended that bicyclists will use the local street system to
access the separated bike path along 24th Street.
STAFF COMMENTS:
The following stipulations need to be placed on the CDP in order to assure
development consistent with the requirements of the subdivision ordinance
and the premises upon which the PUD was developed:
1. That the entire length of the public street in the subdivision be
built as part of the first phase of the PUD project, if there is
phasing, and that all utilities be installed as noted in the revised
PUD plan.
2. That a recreation area use and access agreement be signed, guaran-
teeing access to all open space and recreational facilities to all
residents of the PUD, including the conventional single family lots as
part of the administrative plat approval.
3. That an ordinance be adopted as part of the approval of the Final
Plat restricting parking to the west side of Prairie View West from
the single-family lots south and on the south side of Prairie View
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East and prohibiting parking on both sides of Prairie View West
north of the single-family lots.
4. That the Final Plat not be approved and no building permits be
issued, if any lots of record are split by ownership into different
entities.
The Planning and Zoning Commission reviewed this request at their meeting
of July 2, 1991 and have made no recommendation since two Commissioners
abstained from voting, two Commissioners voted for a recommendation of
denial, and two Commissioners voted against a recommendation of denial.
ALTERNATIVES:
1. The City Council can approve of the Conceptual Development Plan
(CDP) for Prairie West with the stipulations listed above.
2. The City Council can deny approval of the Conceptual Development
Plan (CDP) for Prairie West.
3. The City Council can table action on this request and refer this
issue back to City staff for further information.
MANAGER'S RECOMMENDED ACTION:
An issue has been raised regarding the existence of a wetland on the
proposed subdivision. Recent staff research has found that there is a
small ( .9 acre) area that has been identified by the SCS as a potential
wetland. Two points should be emphasized regarding this issue.
1. The Soil Conservation Service has not conclusively determined that a
wetland area truly exists. Further, the Soil Conservation Service is
advising that the designation of an area as a potential wetland
should not be misused since there is a likelihood that potential
wetland areas may ultimately be determined to not be wetlands.
2. The City of Ames has not made any conclusive legislative determina-
tion that the City's efforts at limiting negative affects on wetlands
should be more restrictive than the wetland protection measures of
the Department of Natural Resources under Section 108 of the Code
of Iowa.
Therefore, it is the recommendation of the City Manager that the City
Council adopt Alternative #1. This will approve of the Conceptual
Development Plan (CDP) for Prairie West with the stipulations stated
above.
Attachment
y\bpo\caf\prairie.709
Edward J. Kannel, P.E.
2314 Melrose Ave.
Ames, Iowa 50010
December 19, 1990
Mr. Paul Popelka
Engineering Plus
319 LincolnWay
Ames, Iowa 50010
Dear Mr. Popelka,
Enclosed is a brief report showing the results of the
evaluation of the proposed Prairie View West Development. Ole
study includes a review of the -potential trip generation and the
impact on the quality of service on the adjacent street and -the
.exit from Prairie View.
A summary statement would be that I do not expect the
additional traffic from the development- to cause a deterioration
of flow on 24th Street. . Peak period users making left turns from
Prairie View will experience delays, but these are in the range
expected in normal travel. Further, the -additional load placed
at the nearest major intersection will not change the rated Level
of Service at that intersection.
Mr. Scott Logan asked that I also consider what would happen
to traffic if a new school, with a drive across from this
development, were to be initiated. While this is an interesting
question and an important issue for the School District and the
.city; I have not included -any of this analysis in the report.
This did not seem appropriate for the- question at hand.
Please let me 'know if their are other aspects of these
analyses that you need for your reviews with the city.
Yours truly,
Edward J. Kannel, PE
Pf2AII2IE VILW WEST
Traffic Analysis
n-ie Prairie View West traffic study presents an estamate of the vehicle
trip tiara within the study area by day and by peak hour, an.evaluation of
traffic at the of Prairie View
the duality of flow far i ct on quality of flow on 24th Street. In
West with 24 th St., and the . n�a
addition, the effect of additional peak4yxx traffic at the intersection of
24th and Stange Road is e3�ed.
Trin Generati
The {xi p gyration rates are based ari the Institute of Transportation
Errjineers art, TRIP (ENERATICU, 4th ed..
Soup Units Daily 1:�ate Daily AM Pk. AM PM.Pk. PM
per' emit Tr'1 ate rate
Single Fain. 7 10.1 71 0.75 5 1.0 7
Apts. 52 6.6 343 0.5 26 0.7 36
Townhouse 40 5.9 236 0.4 16 0.6 24
Duplex* 10 6.4 64 0.5 5 0.6 6
714 52 73
*Average rate, if the high= wit rate is used for all noarsingle family
units, the total trips for all torts is approximtely 750.
Since traffic prablems are typically related to the peak hours, those
values are of greatest importance-
"Vel of service at 24th St. and Dra 1 Y'i a View West
Traffic vraluns during the peak �' on 24th St~ were provided durirXJ
=Wrung, noon and evening peak hours by the City of Ames. Although the counts
regent a small sample and were taken approximately tqo blocks from the
proposed Ittersecticn, they praAde a good base for analysis. Short period
counts taken at the Prairie View East intersection are consistent with the
other data.
Procedures for evaluating the capability for this i:ntersec cn to proves
quality flaw conditions are based on the unsignalized intersection procedures
of the Transportation Pesear h Board, Mghway Capacity Mammal.
AM Peak the units was
Approximately 80% of the AM peak traffic generated by
assumed to be exiting the minor Street with an equal distribution of traffic in
each direction at this T-intersection. A sketch of the turning movenlents is
shown below:
�- Y67
Mie following suanarizes the quality of service on the various legs and the
reserve capacity. Me- Level of Service (DOS) is viewed math like a gradi
scale. Level of Service A is excellent, Level of service C and D are common in
urban awirawmits, and Level .of Service E usually signifies capacity or
raxim= desirable delays have been reached.
Tavel of Service paved capacity_(pass cars per hour),
24th A 820
Prar.View Left D 194
Prar.View Right A 839
Combined Prar. V C
PM Peak
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The traffic volumes expected for the development are added to current
volumes and shm n below for the FM peak period. . The FM peak is typically the
highest volume period. Zhe table below the sketch indicates that the level of
service has not changed, but the reserved amity, eampared to the AM Leak,
has declined clue to the higher volumes.
-F-
#3I
10 !s .
Prcc;ri 6. 6C&V Fez
Invel
Of $OLvlc@ PbeseLy+ed Capacity(pa_!s. Car 5 per hour)
24th A 542
Prar.View Left D 133
Prar.View Right A 702
Ccobined Prar. V C
The laaes-t quality of service is suffered by the left turning vehicles, during
this peak period only 10 vehicles are estimated to be raking this turn.
Validation with Existing Operations
A 30 minute period frown 7:30 to 8:00 AM on Zhursday, November 29,1990 was
studied for actual delay times for left and right turning vehicles at Prairie
View East. The average delay for the 9 left turning vehicles at this
intersection was -8.8 seconds with a maximum delay of 20 seconds. Four right
(2)
t
t=ming. vehicles had an average delay of 5.0. seconds. niese. are cezt�ly in • .
the acceptable range. Signalized ich delays;of 5 to 7 5 =Seconds are
comidered to be Level of Service-B. You shotld be aware that the criteria for
describing Level or quality of service is not the same for these two different
inteisecUon types.
�,ro 3cG at 24th and Starr
Since the additional. traffic from the subdivision can irpact an adjacent
stet , the city traffic engineer asked that the 24th Street and
Stange Mad be evaluated. Although the PM peak adds the most traffic, 25
vehicles, the AM peak is shown here beige the 20 left turniux9 vehicles would
potentially cause the greatest difficulty.
Ttle folloaaing' sketch shows the traffic counts as dyed by the Traffic
Engineering office on 12/IV1990.
-�— 33
•21 103 5 znye' PQva'il
Sassed on these volumes and the standIardized procedures of the Highway
opacity Manual, the results obtained indicate:
,evel Of c3pacity(Uass cars r r hour) .
24th- IQft turn D 196
Stange Rd, L. tarn E 44
Stange pd., R. turn A 629
Obviously, the left turn mavownts are subject to delays durIM the peak
movement time at this i at this time. Addition of the 20 vehicles
from the proposed development did not change the letter.quality of the High;r
city Marmal prooedUr a for quality of flow. She new table is not
shm;n,he3;e; the major di.fferer a is that-the reserved capacity is-reduced from
196 to 172,in the left turn lane from 24th St.
Arty equivalent new residential development in the northeast portion of
town would place this same loan at this intersection. Since the
proposed develop ent does not attract additional traffic as would say a
develop,,, no further analysis at-the Stange Road intersection was
undertaken at this time.
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