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Home My WebLink AboutBURNS RANCH AT QUAIL RIDGE AMENDED RF SITE PLAN AND 2ND FILING FINAL - 23 90D - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE AND EROSION CONTROL STUDY FOR IRNS RANCH AT QUAIL RIDGE SECOND FILING control performance standard for the subject site is 84.0%. From the calculations in the appendix, the effectiveness of the proposed erosion control plan is 85.0%. Therefore the erosion control plan as specifically detailed below, meets the City of Fort Collins requirements. B. .Specific Details th well blished rassesi This Basin 1 consists of native vegetatace anion ld therefore athe existing vegetation is being planned for open sp should be maintained: ots Basin 2 is planned for the developmentdrainage draw traverses throughlbas basin and the sewer system. A natural dra g drainage draw will be retained. The rear half of the estate residential lots lie within basin 2 and minor runoff from ses within the open space The nativethe lawns is anticipated to sheet into the existing native Colorado g gasses should remove any sediment leaving the rear half of the residential lots and no impact is anticipated to existing area easeshallAhave a fter the overlot grading has been completed, alldisturbed. temporary vegetation seed applied. After seeding, a hay or straw mulch rate 2/acre min.and the mulch shall be applied over the t tacked,f or ocrimped nsinto the soil.. After shall be adequately anchored, installation of the storm sewer syBefor�eaconpers uctionanent voneeach of the 10 straw mulch shall be app' residential lots, a temporary silt fence shall installed across ed the within the each lot and remain until construction has been been comp individual lot. Basin 3 is planned for the development of estate residential lots and half of Skimmerhorn. Street. After the the rloota way surfaces shouldading has been lerece receive the and the utilities have been installed, pavement structure. After installation of the curb inlet, the inlet shall be filtered with a combination of concrete blocks, 1 /2" wire screen and coarse gravel (3/4"). Basin 4 is planned for the development of 16 estate residential lots, half of Skimmerhorn Street, and all of Nesbit Court. After the ovevoet gradihas ng seed been completed, all disturbed areas shall have a temporaryapplied over the seed applied. After seeding, a hay or straw mulch shall be at a rate of 2 tons/acre ( the soil and the methodsbon this the mulch shall s sheet,a Afterrthe tacked, or crimped into p utilities have been installed, the roadway surfaces should receive the pavement structure. After installation of the curb inlet, the inlet shall be filtered with a combination of concrete blocks, 1 /2" wire screen and coarse fi 9 gravel (3/419). Basin 5 consists of native vegetation with of well established grasses. This area is being planned for open space and therefore the existing vegetation should be maintained. VI. CONCLUSIONS A. Comaliance with Standards All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria and the Erosion Control Reference Manual for Construction Sites. B. Drainage COnQU-1 The proposed drainage concepts adequately provide the detention of developed on -site flows from the Second Filing of Burns Ranch at Quail Ridge. By utilizing the detention pond in Filing No. 5 of Quail Hollow, all developed storm wager runoff from the subject site will be controlled in order to eliminate off -site downstream damage from the 2 year and 100 year storm events. The proposed storm sewer system will adequately remove storm water runoff and snowmelt flows from Skimmerhorn Street for up to the 100 year storm event. The proposed street systems will adequately transport storm water runoff to a low point in Skimmerhorn Street at the sump inlets of the storm sewer system. I The Second Filing of Burns Ranch at Quail Ridge design is dependent on existing offsite development within Quail Hollow Filing No. 5 in order to detain developed runoff and release the runoff at historic conditions. Also the design depends on offsite development within Quail Hollow future Filing 7 in order to transmit storm water runoff through the Quail Hollow future filing to the existing storm sewer.system within Quail Hollow Filing No. 6. For this report it has been assumed that Burns Ranches, Inc. will coordinate their drainage needs with d. Jensen Enterprises in order to minimize the _ impacts to the Quail Hollow Subdivision. The proposed drainage concepts presented in this report and shown on the - drainage plan are in compliance with the City of Fort Collins drainage criteria. 7 C. Erosion Control Concept The proposed erosion control concepts adequately provide for the control of wind and rainfall erosion from the Second Filing of Burns Ranch at Quail Ridge. Through the construction of the proposed erosion control concepts, the City of Fort. Collins performance standards will be met. The proposed erosion control concepts presented in this report and shown on the erosion control plan are in compliance with the City of Fort Collins erosion control criteria. REFERENCES 1. Storm brainage Design Criteria and Construction Standards by the City of Fort Collins, Colorado, Revised January 1991. 2. Erosion Control Reference Manual for Construction Sites by the City of Fort Collins, Colorado, January 1991. 3. Quail Hollow Subdivision, Filings 4 through 7, Preliminary Drainage Report by RBD, Inc., Engineering Consultants, November 1989. 4. Final Drainage Report for Quail Hollow P.U.D., Third Filing by RBD Inc., Engineering Consultants, March 1990. 5. Preliminary Drainage Report for the Burns Ranch at Qua.'il Ridge by RBD, Inc., Engineering Consultants, December 21, 1990. 6. Spring Creek Major Drainageway Plan for the City of Fort Collins, Larimer County Colorado by Gingery Associates, Inc., August 1980. 7. Final Drainage Study for the Quail Hollow Fifth Filing by RBD Inc., Engineering Consultants, May 1991. 8. Final Drainage and Erosion Control Study for the Quail Hollow Sixth Filing by RBD Inc., Engineering Consultants, April 1992. 0 APPENDIX C- i�>i ererYwsrOC A` r R.f Jetr W m er4- PI- � ci renOnft dR. ' r R {F m •. l 'n a`` =; p w Laurel I ••�� a. dura i /�4 m u m � ..NerrA D• WWP 4 W _ u• ��_... w Rum Sr All V El.rrb.1h - N - =s.J S1. cl • ^ - orgy E �L,ea4aN .I . e OT010 ♦ O Cl C, '�A WnlYe ra Dr - r I r P•. a _ Lete .eoa b 'a .rrN. •m..Dr. ` INN n. , :. 3 e _ S� ;demo a ,< a •eel4 , iw 1 e + ,rw D t :n.n cf. � IN Las, W. LaN SI. O 1 F St N"°I EPiSPE T :s `I » W:L amwa... :1 ROAD N J. I r n. J all, 1 14wIC - '�. � R it. Ceee�i lq,� i ✓ Nm • •• ✓ ! She I � Cs , C lon ♦ p. njj - •erlA Rs i t91 � C•ek a SniU n•nrnrl, I -.4 . W..SLYarI Sf �M1 Y .� ®_ 9• . � � nrno..,•r. SI. .: ' . E d �� Gs. ��°q r� -`S• �^....... �pjal ra "+� ih W SlVerl J �\ �r r 3 _ C o- R a c►n.ok Dr a s•mn.<a% Ga, C4 r cr. cwl::ia a ir, D. NYPa Q� Y ®®1 O .OY1 �♦ems � r � � * 3 � 'ar G, i N r.r+ VyV \..p�1 n IRA P' �t{ \... 1 Or. CI. • - u a1uJ. , . 6:rinvNagyq ,t t� - 't. Confor4- � (;: � �r1. °• Con . wad {I •u u a ® n clUY . � E2 OAD w: Dr. :rM Cr Irnm - i lb, Dr •�, a. /1P:Trur • .n N t• I 6 rWA Q Y / T Null sr r N ti L i NYma a. 1,• V - f b. nu _ ia, �� ♦.�� •� H 17nt-01...1 a.Y 0 YS 3 �.. �••�\ `. �° W. YA.:.e�• � fi a' r �1 t 1 J Mel fat' •-OFrt v S loos 9M.. 9 P • . �. Y U • tNr Rrt, � • jlr�• rf Rimlttt R � C� Cli � � b{ , u �. S •.,4 y� r ® SITES =` \� � �° °"a'� :.a �� — • •, J G M G1. \ E • n • Ch C7 � ®� a. \...r� � ', •ter _ Y fo: _ S S ."" i I '1 �• 1 k al:l r } l N N •any - I ,¢ d rod'..L.o=aanM 1 W H R D w.dood Nr.rleei _Re 51 t f N 6 j,\ J Olt+ . 0 1 NP B.aat Dr nC. u 4 a a �F m 1 \ a P.JI `q ®®i{ Pwre K v MSaltklf Dr Wp . 1 \ n \bb �.,� •••J it d E MS�t/' or = e 1 '` Motlr Dr 1 S g u a LW Rower PI cwno Road- Dtar z a r . 1 C Brh Rd Wrty ` Vic IN STY _ e `� 1'IaJN CL o PAA P 4 A Land, do '9D'I}0 s e OA 4 r.�� 1 fro. � ( �y `,1. •. s d FINAL DRAINAGE AND EROSION CONTROL STUDY FOR BURNS RANCH AT QUAIL RIDGE SECOND FILING February 1, 1993 Prepared for: Burns Ranches, Inc. 2837 Overland Trail Fort Collins; Colorado 80526 Prepared by: RBD, Inc. Engineering Consultants 209 S. Meldrum Fort Collins, Colorado 80521 (303) 482-5922 RBD Job No. 394-007 INC. Engineering Consultants 209 S. Meldrum Fort Collins, Colorado 80521 303/482-5922 FAX: 303/482-6368 February 1, 1993 Ms. Kathy Malers City of Fort Collins Utility Services Stormwater 235 Mathews Fort Collins, Co. 80522 RE: Final Drainage and Erosion Control Study for Burns Ranch at Quail Ridge Second Filing RBD Job No. 394-007 Dear Kathy We are pleased to submit to you, for your review and approval, this Final Drainage and Erosion Control Study for Burns Ranch at Quail Ridge Second Filing. All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. Thank you for your time and consideration of this submittal. Please call if you have any questions. Respectfully, RBD Inc. Engineering Consultants �-G� al A� �/ Kevin W. Gingery, P.E. Project Manager Water Resources CC: Mr. Rex Burns - Burns Ranches, Inc. Other offices: Denver 303/458-5526 • Vail 303/476-6340 TABLE OF CONTENTS DESCRIPTION -PAGE I: GENERAL LOCATION AND DESCRIPTION A. LOCATION B. DESCRIPTION OF PROPERTY II. DRAINAGE BASINS AND SUB -BASINS A. MAJOR BASIN DESCRIPTION 1 B. SUB -BASIN DESCRIPTION 1 III. DRAINAGE DESIGN CRITERIA A. REGULATIONS 2 B. DEVELOPMENT CRITERIA. REFERENCE 2 AND CONSTRAINTS C. HYDROLOGICAL CRITERIA 2 D. HYDRAULIC CRITERIA 2 E. VARIANCES FROM CRITERIA 3 IV. DRAINAGE FACILITY DESIGN A. GENERAL CONCEPT 3 B. SPECIFIC DETAILS 3 V. EROSION CONTROL A. GENERAL CONCEPTS 5 B. SPECIFIC DETAILS 6 Vl. CONCLUSIONS A. COMPLIANCE WITH STANDARDS 7 B. DRAINAGE CONCEPT 7 C. EROSION CONTROL CONCEPT g REFERENCES 8 APPENDIX A VICINITY MAP 1 HYDROLOGY 2 DETENTION 5 DESIGN OF INLETS, STORM SEWER AND SWALES 7 EROSION CONTROL 17 CHARTS, TABLES AND FIGURES 21 FINAL DRAINAGE AND EROSION CONTROL STUDY FOR BURNS RANCH AT QUAIL RIDGE SECOND FILING I. GENERAL LOCATION AND DESCRIPTION A. Location The Burns Ranch at Quail Ridge Subdivision is located southwest of Overland Trail and Skimmerhorn Street and is bounded on the west by Dixon Reservoir and on the east by the Quail Hollow Subdivision, in southwest Fort Collins, Colorado., The site is shown on the Vicinity Map in the Appendix. More particularly, the site is described as Burns Ranch at Quail Ridge, Second Filing, and is situated in the Northeast 1 /4 of Section 29, Township 7 North, Range 69 West of the 6th P.M., City of Fort Collins, Larimer County, Colorado. B. Description of Property The Second Filing of Burns Ranch at Quail Ridge contains 28.09 acres more or less. Currently the site is undeveloped and contains native Colorado grasses. The property is being proposed as a foothills residential development with large open spaces within the City of Fort Collins Foothills Zoning District (RF Zone) and 26 residential lots. Topography at the site is generally sloping from west to east at approximately 6%. An existing farmers irrigation lateral, owned by the Dixon Irrigation Co., traverses the subject site in a northwest to southeast direction.. 11. DRAINAGE BASINS AND SUB -BASINS A. Major Basin Description ' No major drainageway exists in the Second Filing of Burns Ranch at Quail Ridge. The Burns Ranch property does drain into Spring Creek per the Spring Creek Major Drainageway Plan by Gingery Associates, Inc. dated August 1980. The City of Fort Collins is planning a regional detention pond on the southwest corner of Drake Road and Taft Hill Road in the future. B. Sub -Basin_ Description Historic drainage patterns on the subject site are easterly across the site towards Spring Creek, or westerly into Dixon Reservoir. Historic drainage 1 flows from the Burns Ranch Second Filing cross the Quail Hollow Subdivision Future 7th Filing, travel through the Quail he Sixth Filing storm sewer system, enter the Quail Hollow Fifth Filing detention pond, and outlet to Spring Creek. Historic off -site storm water runoff from the ridge line west of the Second Filing of Burns Ranch is currently draining onto or across the subject site. 111. DRAINAGE DESIGN CRITERIA A. Rgaul___ atlons The City of Fort Collins Storm Drainage Design Criteria is being used for the subject site. B... . Development Criteria Reference and Constraints A preliminary drainage report was previously completed for the subject site. The Preliminary Drainage Report for Burns Ranch at Quail Ridge developed the design criteria -for the subject site. With the development of Filing No. 5 of Quail Hollow during the summer of 1991, a detention pond was constructed. The City of Fort Collins is planning a regional detention pond on the southwest corner of Drake Road and Taft Hill Road in the future. Until the regional detention pond is constructed, the City of Fort Collins has required that temporary detention ponds be constructed within the upstream developments in order to protect the downstream property owners. The detention pond in Filing No. 5 of Quail Hollow has adequate outlets and detention to reduce developed flows to historic conditions as .drainage waters leave the site and enter Spring Creek. Per the report titled Final Drainage Study For The Quail Hollow Fifth Filing it states `'The proposed drainage concepts adequately provide the detention of developed on -site flows from the Quail Hollow Subdivision Filings 4 through 7 and the proposed Burns Ranch at Quail Ridge Subdivision' . C. Hydrological Criteria The rational method was used to determine runoff peak flows from the site. The 2 and 100 year rainfall criteria, which was obtained from the City of Fort Collins, is the criteria which was utilized. This criteria is included in the Appendix. D. Hydraulic Criteria All calculations within this report have been prepared in accordance with the 2 City of Fort Collins Drainage Criteria. E. Variances from Criteria No variances are being proposed for the Burns Ranch Second Filing. IV. DRAINAGE FACILITY DESIGN A. General.Conceot As development occurs within the Second Filing of Burns Ranch at Quail Ridge, all on -site fully developed flows will flow easterly and eventually into the detention pond in the Fifth Filing of the Quail Hollow subdivision. Included in the back pocket of this report are the Burns Ranch at Quail Ridge Second Fling drainage plan, grading plan, and storm sewer plan and profile. B. Specific Details The existing farmers irrigation lateral traverses the subject site in a northwest to southeast direction.. The Burns Ranch property is underlain by sandy silt on top of siltstone, claystone and sandstone, and due to the slope of the site, groundwater in not anticipated to be a problem in the development of the site. If for some unforeseen reason ground water is encountered during construction, a Colorado Department of Health Construction Dewatering Permit would be required. The Spillway outlet for Dixon Reservoir is not located in the proximity of the Burns Ranch property. During the course of preparing the proposed drainage plan for the Second Filing of Burns Ranch at Quail Ridge, the question arose as to the possible opportunity for the Second Filing of Burns Ranch storm water runoff to be redirected through the First Filing of Burns Ranch. We researched the possibility of allowing storm water from the Second Filing to pass down Skimmerhom Street through the First Filing of Burns Ranch. Due to lack of freeboard in the Quail Hollow Filing No. 3 detention pond and existing drainage constraints at the outlet of the existing 48" RCP under Yorkshire Street into the Quail Hollow Filing No. 5 detention pond, redirecting storm water runoff from the Burns Ranch Second Filing through the Burns Ranch First Filing was not a possibility. From the Preliminary Drainage Report for the Burns Ranch at Quail Ridge development, storm water runoff from the Second Filing was planned to be directed easterly through the future Quail Hollow Filing No. 7 development by an existing drainage draw which originates along the eastern portion of 3 the Burns Ranch Second Filing. Runoff from basins 1 and 5 of the Second Filing of Bums Ranch are proposed to remain as open space in their natural historic flow patterns. Basin 1 naturally sheet flows easterly into the Quail Hollow Subdivision and towards Spring Creek. Basin 5 naturally sheet flows westerly into the Dixon Reservoir. The existing Farmers Irrigation Lateral traverses through basin 2. Basin 2 is planned for the development of 10 estate residential lots and a storm sewer system draining a low point in Skimmerhorn Street. An existing drainage draw traverses through basin 2 and the drainage draw will be retained. The drainage draw originates in. basin 2 and extends easterly to Overland Trail. Within the existing drainage draw, two vegetated treatment systems exist where wildlife and vegetation are well established. These existing treatment systems have acted as natural water quality mechanisms for numerous years and aid in the removal of surface pollutants carried in storm water runoff from the existing Burns Ranch undeveloped property. The rear half of the estate residential lots lie within basin 2 and minor runoff from the rear lawns is anticipated to sheet flow into the existing native Colorado grasses within the open space of the Second Filing of Burns Ranch. The native grasses are anticipated to remove sediment leaving the rear half of the residential lots and no water quality impact is anticipated to the existing irrigation lateral. From the outlet of the proposed storm sewer system in the Burns Ranch Second Fling, a concerted effort has been made to utilize the existing vegetated treatment systems to improve the water quality of storm water runoff leaving the Burns Ranch Second Filing. An energy dissipation manhole is proposed on the storm sewer system to reduce the velocity of storm water leaving the piped system to a non -erodible velocity in order to preserve the existing vegetated treatment system. As pollutants transmitted in the storm sewer system pass through the existing vegetated treatment systems, solids will have the opportunity .to settle out and thus improve water quality of the storm water. No riprap is proposed at the outlet of the storm sewer system because in order to place riprap, an existing vegetated. treatment system would be destroyed. We believe the existing vegetated treatment system should be saved and utilized.' Between the Burns Ranch Second Filing and Overland Trail to the east, lies the future Quail Hollow Filing No. 7. Some years ago the farmers who owned the property now known as the Quail Hollow future Filing No. 7 elected to place an earthen berm across the existing drainage draw which drains the Burns Ranch Second Filing. The earthen berm was not placed 4 with conventional construction equipment and thus compaction was lacking. In order to allow storm water runoff from the Second Filing of Burns Ranch to reach the existing roadside ditch adjacent to Overland Trail, the existing earthen berm should be removed. An existing drainage ditch currently lies between the earthen berm and the roadside ditch adjacent to Overland Trail. The existing drainage ditch does not have adequate capacity to transmit 100 year storm water runoff from Burns Ranch Second Filing to the roadside ditch along Overland Trail. Therefore we are proposing to improve the existing drainage ditch in order to carry the required storm water runoff by flattening out the existing 1:1 side slopes to 3:1 side slopes. After the drainage ditch has been reshaped, a grass seed, mulch, and erosion control blanket are proposed over the ground to prevent erosion. Included in the appendix are copies of the manufactures literature on the erosion control blanket. The erosion control. blanket is also proposed for the existing westerly side slope of the temporary drainage swale along the western side of Overland Trail. Basins 3 and 4 are planned for the development of 16 estate residential lots and a storm sewer system draining a low point. in Skimmerhorn Street: In order to pass storm water collected in Skimmerhorn Street under the existing Farmers Irrigation Lateral, the storm sewer system has been designed for the 100 year storm event. From a water quality standpoint, we have sought to prevent storm water runoff pollutants from entering the existing Farmers Irrigation Lateral by passing under the irrigation lateral with the storm sewer system. A large portion of Basin 4 is planned to remain in its existing condition as open space, thus providing a natural cleansing mechanism for storm water pollutants to be removed as storm water runoff passes through the existing native Colorado grasses. V. EROSION CONTROL A. General Conceut The Second Filing of Burns Ranch at Quail Ridge lies within the High Rainfall Erodibility Zone and the Moderate Wind Erodibility Zone per the City of Fort Collins zone maps. Due to the existing site slopes of 6% the potential exists for erosion problems after the second filing improvements are completed and the ground is bare. It is anticipated that the second filing improvements will be completed during the summer of 1993. Thus the new improvements will be subjected to both wind and rainfall erosion before new vegetation has taken hold or the new residential lots are developed: Per the City of Fort Collins Erosion Control Reference Manual for Construction Sites and the related calculations in the appendix, the erosion 5