HomeMy WebLinkAboutFOSSIL LAKE RANCH SIXTH PLANK PLD AND PD - Filed GC-GENERAL CORRESPONDENCE - 2007-11-20' e ~
(NORTHERN
ENGINEERING
August 29, 2006
ADDRESS: PHONE:970.221.4158 WEBSITE:
200 S. College Ave. Suite100 wwanorthernengineeringxom
Fort Collins, CO 80524 FAX: 970.221.4159
Ms. Traci Downs, P.E.
Larimer County Engineering
Development Review
200 West Oak Street, Suite 3000
Fort Collins, Colorado 80522-1190
RE: Plank PLD & PD (Being the 6"' Filing of Fossil Lake P.U.D.)
Request for Variance on Cul-de-sac
Ms. Downs,
This letter is in regards to the Plank PLD & PD project (aka, Fossil Lake 6t' Filing).
Stan Everitt of the Everitt Companies is the Developer/Applicant. The site is located
at the southeast corner of the new Kechter and Ziegler roundabout. The project has
already obtained its Preliminary Plat approval, and is in the Final Plat phase. A
variance is requested to modify the vertical criteria for the cul-de-sac at Cardinal
Flower Court, as shown on the Final Utility Plans (Sheets R2 and R5).
Chapter 7 of the Larimer County Urban Area Street Standards (LCUASS) addresses
the Street Design and Technical Criteria for public roadways. More specifically,
vertical design requirements for cul-de-sacs are depicted in Figure 7-19. The
minimum and maximum flowline grades around the cul-de-sac are 1.0% and 3.0%
respectively. The minimum and maximum pavement cross -slopes are 2.0% and
3.0% respectively.
Everitt Companies has experienced difficulties in the field when cul-de-sacs are
designed with the 2.0% minimum cross -slope. The problems center around
inadequate drainage of the pavement resulting in failures at the asphalt/gutter seam
and warranty/repair work, which is undesirable to everyone. We feel that these
issues can be curtailed by increasing the cross -slopes on the design drawings.
We are proposing a maximum cross -slope of 3.5% within the cul-de-sac. Please
note that this maximum slope is isolated to a couple of areas. However, what this
enables throughout the rest of the cul-de-sac is cross -slopes in the 2.5%-3.0%
range, which are desired above the 2.0% minimum (or flatter). 4.0% pavement
slope is acceptable for reconstruction, and used to be allowed for new construction
of through streets. Therefore, we do not believe this is a major variance from the
sta ndards.
In order to keep the cross -slope from getting too steep near the low point of the cul-
de-sacs, we are also proposing a variance to the LCUASS (Fort Collins) minimum
flowline grade in cul-de-sacs. Adhering to the 1.0% minimum flowline grade around
the entire cul-de-sac will lower the sump elevation, thereby increasing the maximum
pavement slope near 4.0% or greater. We are proposing a minimum flowline grade
of 0.50%, which used to be allowed in Fort Collins, and still is in other areas
governed by LCUASS. Once again, this is not a major variance. Also note that the
amount of curb and gutter at 0.50% is extremely limited, and occurs adjacent to the
steepest asphalt cross -slopes. These sections of curb and gutter will be hand -built
and poured monolithically with the inlet tops to ensure flowline grades are achieved.
We feel justified in requesting the variance listed above. We have previously
discussed cul-de-sac requirements with Fort Collins' Development Review Staff and
their Engineering Inspector, and there has been an acknowledgement to perhaps
modify the standards. The cul-de-sac design proposed with Fossil Lake 6`h Filing is
intended to improve the constructed product. Field evidence and testimony indicate
that cross -slopes designed at 2.0% result in poor drainage and pavement failure.
We do not believe this variance will be detrimental to public health, safety or
welfare. We also trust that this proposal will not adversely affect the design life of
the roadway or increase future maintenance costs; in fact, we aim to achieve the
contrary.
For your information, a similar variance was recently granted for the cul-de-sacs
within the Lemay Avenue Estates subdivision. Please do not hesitate to contact us if
you have any questions.
Sincerely, ��%
l,I{l(l W.gu�
Nicholas W. Haws, PE
Project Manager
CC: Stan Everitt — Everitt Companies
Aaron Everitt — Everitt Companies