COD Standards and Specs_201207301019189063_201309061119558754.pdf

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Development Standards for Public Improvements and

Construction Specifications

Table of Contents

Amendment

Section 1 Development and Construction Standards (Includes Streets & Sidewalks, Water, Sewer, Storm Sewer)

Section 2 Utilities

Section 3 Standard Specifications

Section 4 Specification Drawings

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Development Standards for Public Improvements and

Construction Specifications

Amendment

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CITY of D

Public Works Department 949 E. 2nd A venue Durango CO 81301-5109 970·385-2860

970-385-7786 (FAX)

To Whom It May Concern:

November 30,2001

This book includes changes to the· City of Durango Code of Ordinances regarding street layout and design.

The following Amendment is applicable to Section 1 ~Development and Construction Standards.

If you have any questions, please contact the Public Works Department at 385-2860.

Yours truly, Otha J. Rogers, P.E., Director Public Works Department l l

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Sec. 14-181. Street layouts and designations.

Arrangement of streets and selection of typical road sections shall conform as nearly as possible to and be compatible with the objectives established by the City Master Plan. In all cases, provisions shall be made for the extension of arterials and collectors, as designated on the master plan.

In neighborhoods designed for residential development, streets, except for cui-de-sacs, shall be configured to encourage low vehicle speeds. Streets designed for residential development shall have no reach of street longer than 800 feet without at least one of the following features: traffic turnaround, offset intersection, cul-de-sac, center landscaped median, curve of at least 90 degrees with a radius of no more than 200 feet, or drainage structures which require reduced speed.

Section 2. That Section 14-186 of the Code of Ordinances of the City ofDurango should be and the same is hereby amended, in its entirety, as follows:

Sec. 14-186. Bicycle Ways.

Bicycle ways shall be provided on arterial and collector rights-of-way as shown on drawings numbered R-IB on file in the City Clerk's office. Bike lanes for new roadways shall be at least five (5) feet wide, as measured from the flowline of the gutter. Off-street bicycle ways may be required through subdivisions if they are part of an area bicycle system. Where off-street paved bikeways are provided, they shall have a minimum paved surface of ten ( 1 0) feet in width and a minimum right-of-way of twelve (12) feet in width.

Section 3. That Section 14-19l(e) of the Code of Ordinances of the City of

Durango should be and the same is hereby amended, in its entirety, as follows:

Sec. 14-191. Intersections.

(e) Curb comer radii at intersections shall be between ten (10) and twenty (20) feet, except that comer radii in commercial and industrial areas may be thirty (30) feet.

Section 4. That Section 14-193 of the Code of Ordinances ofthe City ofDurango should be and the same is hereby amended, in its entirety, as follows:

Sec. 14-193. Driveways and curb cuts.

STSPECS.DOC

A maximum of one curb cut per dwelling unit is allowed in any residentially zoned area. Each residential curb cut shall be no more than twenty-four (24) feet wide and each commercial curb cut no more than thirty five (35) feet wide, as shown in standard drawing No. R-4 on file in the City Clerk's office. Curb cuts larger than thirty-five (35) feet in width may be made in industrial zones where no sidewalks are proposed. Curb cuts shall be no closer than forty (40) feet from the intersection of any road as measured from the curbline extended. Curb cuts shall be no closer than twenty (20) feet apart as measured at the right-of-way line. Curb cuts shall be no closer than ten (1 0) feet from the property line as measured at the curb line from the property line extended.

Residential properties fronting collector or arterial roads shall not be allowed curb cuts which require backing into the public right-of-way. Where residential properties front both arterial or collector and local streets, access shall be allowed only from the local street.

In commercial areas, parking shall be accommodated so that no backing into the public right-of-way will be allowed except that backing into the public right-of-way of an alley is allowed.

Section 5. That Section 14-195 ofthe Code of Ordinances ofthe City ofDurango should be and the same is hereby amended, in its entirety, as follows:

Sec. 14-195. Cul-de-sac and dead-end streets.

(a) Dead end streets are not allowed unless provisions are made for turning of emergency vehicles. The minimum pavement diameter for turning shall be seventy (70) feet. Configurations other than circular drives shall be allowed where maneuvering room comparable to a seventy (70) foot Fssiw-s- is

'd d I>IAIIIIITf~ prov1 e .

(b) Dead-end streets proposed to be extended to connect with future development shall be provided with a temporary turnaround which will consist of a seventy (70) foot diameter graveled surface meeting base requirements of the paved section of the street.

(c) Maximum length of cul-de-sac shall be five hundred (500) feet.

Maximum lengths of one thousand (1,000) feet are permitted when serving fewer than twenty (20) dwelling units.

STSPECS.DOC

Development

Construction

Standards

LOCAL PUBLIC IMPROVEMENT § 14-161

all be readvertised, and at the time to whic · s ch sale was postponed shall again be offered r sa e and sold to the highest bidder. Upon the le of y property and the payment therefor a eed shal be executed to the purchaser in the arne man r as provided for the execution of de ds in sectio 14-139.

(Code 1 62, § 9-10-55)

See. 14-1 1. Deposits in surplus and fund.

received by the fina e director/ treasurer on account of the paym t of assess ments or inst llments thereof, the ssignment or redemption of linquency certifi s, or for rents, issues and pro ts, or from the le of property, title to which is eld by the city or the benefit of any local improv ent district ess any expenses of securing posses ·on of such roperty, or for the care and operation nd sale the same, shall be deposited to the ere it of t e interest and bond fund of the local impr verne t district, in the same proportion as the ass m nt or installments for which the property w t en. Any money left in a local improvement d trict bond fund or any money derived from th ntal or sale of any real property acquired by he city through sale for delinquent assessmen or i tallments shall, after all warrants, bonds nd co ons of such district, have been paid in ( II, be cr dited to the special surplus and defici cy fund o the city.

(Code 1962, § 9-1 -56)

Sec. 14-142. S e must equal

The city m use any availabl funds for the satisfaction o any lien prior in ri t to any spe cial assess nt lien created by th city. In the resale of a property to which the city has so acquired t' le, the city shall use its be t efforts to sell the p operty for an amount at lea equal to the fund so used plus the amount nee ssary to satisfy e special assessment lien or 1 ns cre ated b the city, principal, interest, penal · es and collec on costs. The monies received from uch a resa in payment for the property shall be used firs y to satisfy such special assessment lie or lie s and thereafter to restore to the funds f m w ich any such prior liens were satisfied the m n i s used therefor. In accordance with the pro -

·ons of this division, the city is authorized ire and dispose of property on which linquent taxes or special assess ts, or

Sec. 14-143.

Sees. 14-144-14-159. Reserved.

ARTICLE III. DEVEWPMENT AND

CONSTRUCTION STANDARDS

DIVISION 1. GENERALLY

Sec. 14-160. Enforcement.

The provisions of this article shall be enforced and administered by the public works department of the city under the direction and supervision of the director of public works/city engineer.

(Code 1962, § 12-1-1)

Cross reference-Utilities, Ch. 25.

Sec. 14-161. Adoption of standard specifica tions for construction and spec ification drawings.

All construction of public improvements within the city shall be completed in accordance with the Standard Specifications for Construction of Wa terlines, Sanitary Sewers and Storm Drainage Facilities (May, 1984); Standard Specifications for Construction. of Streets and Roads (May, 1984); or Standard Specifications for Construction of Con crete Curb, Gutter and Sidewalk Construction (May, 1984), including compliance with the Specifica tion Drawings which are an appendix thereto (here inafter collectively referred to as "Standard Spec ifications for Construction"). The Standard Speci fications for Construction shall be subject to

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§ 14-161 DURANGO CODE

modification, from time to time, upon recommen dation of the city engineer and the adoption of a resolution by the city council implementing and adopting such changes and modifications as may be recommended by the city engineer. A full and complete set of Standard Specifications for Con struction shall be available for sale to the public at all times at the offices of the department of public works of the city. The cost to the public of acquiring a copy of the Standard Specifications for Construction shall not exceed the actual cost of reproduction of such materiaL Changes or modi fications to Standard Specifications for Construc tion adopted pursuant to resolution of the city council shall be incorporated within the Standard Specifications for Construction as soon as reason ably practical after their approval and adoption.

(Code 1962, § 12-3-1)

Sees. 14-162-14-177. Reserved.

DIVISION 2. DEVELOPMENT STANDARDS

FOR PUBLIC IMPROVEMENTS

Sec. 14-178. Applicability.

(a) Where any provisions of this division im pose more stringent requirements, regulations, restrictions or limitations than the minimums im posed or required by any other provisions of this Code or the statutes of the state, then the provi sions of this division shall govern.

(b) No public improvements shall be installed nor shall any platted or dedicated street be used or improved except in compliance with this divi sion. Whenever in this division, an action of the city council or an action of the planning commis sion requires the subdivider or developer to in stall water or sanitary sewer mains in the subdi vision or development with an increase in size designed and intended to serve land other than that located within the subdivision or develop ment, an agreement with the subdivider or de veloper to reimburse him for the cost of the in creased size of the water or sanitary sewer mains may be entered into by subdivider or developer and the city council.

(c) All construction and installation of public improvements shall require compliance with ap-plicable regulations pertaining to landscaping pur suant to section 26-16 et seq.

(Code 1962, § 12-2-1)

Sec. 14-179. Definitions.

All words used in this division, except where specifically defined in this section, shall carry their customary meanings when not inconsistent with the context. The following words shall have the definitions ascribed to them in this section whenever they shall appear in this division:

Backfill means material placed in an excavated space to fill such space.

Base course means the upper course of the granu lar base ofthe pavement or the lower course of an asphalt concrete pavement structure.

Culvert means any structure not classified as a bridge, which provides an opening under or adja cent to the roadway.

Pavement means any surfacing of streets, al leys, sidewalks, courts, driveways or similar areas, consisting of mineral aggregate bound into a rigid or semi-rigid mass by a suitable binder such as, but not limited to, portland cement or asphalt cement.

Pavement structure means the combination of subbase, base course, and surface course placed on a subgrade to support the traffic load and dis tribute it to the road bed.

Private street means any vehicular access serv ing residential properties whose average daily traf fic volume exceeds sixty (60) trips a day.

Public improvements means public facilities and shall refer to the construction or installation of streets, including curb and gutter, sidewalks, de velopment or extension of the city water system, city sanitary sewer system, city storm sewer sys tem, and landscaping.

Right-of-way means land, property or interest therein, usually in a strip, acquired for or devoted to a street, highway or other public improvement.

Road means an open way for purposes of ve hicular and pedestrian travel.

LOCAL PUBLIC IMPROVEMENT § 14-183

Roadway means the improved portion of the right-of-way intended primarily for vehicular traffic.

Sewers means conduits and related appurtenances employed to collect and carry off water and waste matter to a suitable point of final discharge.

Shoulder means that portion of the roadway contiguous with the traveled way for accommoda tion of stopped vehicles, for emergency use, and for lateral support of base and surface courses.

Sidewalk means that portion of the street pri marily constructed for the use of pedestrians.

Storm drain means any conduit and appurte nance intended for the reception and transfer of storm water.

Street the improved area of the right-of-way.

Structures means bridges, culverts, catch basins, drop inlets, retaining walls, cribbing, manholes, end walls, buildings, sewers, service pipes, under drains, foundation drains, fences, swimming pools and other features which may be encountered in the work and not otherwise classed in this division.

Subbase means the lower course of the base of a roadway, immediately above the subgrade.

Subgrade means the supporting structures on which the pavement and its special undercourses rest.

(Code 1962, § 12-2-2}

Cross reference-Definitions and rules of construction gen erally,§ 1-2.

Sec. 14-180. Street and sidewalk standards generally.

The standards set forth in this division for right of-way and road design are to be used in the de sign and construction of all new roads and as guides in the improvements of the existing street system. The objective in presenting street devel opment standards is to establish factors which should be considered in the design process. The standards set forth in this division have been adopted by the city in the interest of safety, aes thetics and maintenance expense to the taxpay ers of this community. All construction plans for roadways, sidewalks or bikeways shall be approved by the city engineer prior to beginning construction.

(Code 1962, § 12-2-3(A)) Supp.No.4

Sec. 14-181. Street layouts and designations.

Sec. 14-182. Access to buildings.

Access to buildings must be provided in accord ance with the Uniform Fire Code, as published by the International Conference of Building Officials, chapter 10.107{a) and (c). Except for course and cui-de-sacs, streets will connect with streets al ready dedicated in adjoining or adjacent subdivi sions, or provide for future connections to adjoin ing unsubdivided tracts, or should be a reasonable projection of streets in the nearest subdivided tracts.

(Code 1962, § 12-2-3{C))

Sec. 14-183. Rights-of·way.

(a) Street rights-of-way must be sufficient to accommodate vehicular traffic, bicycles, pedestrians, all public utilities and on-street parking, special storm drainage facilities or other special treat ments such as medians or traffic channelization.

(b) In accordance with the urban street stand ards see drawings numbered R-IA through R-1E on file in the city clerk's office for all public ways hereafter dedicated and accepted, the minimum right-of-way for streets, alleys, bikeways or pe destrian ways shall not be less than the mini mum dimensions for each classification as follows and shall be in accordance with the city master plan:

Type of street

Major arterial Collector Local Court Cul-de-sac Alley

Length (in feet)

60 (radius)

(c) Greater widths may be required by the city engineer when the need for such additional width

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§ 14-183 DURANGO CODE

is supported by a traffic study. A drainage ease ment, in addition to the provided street right-of way width, may be required where streets paral lel streams or drainage area. The widths of such drainage easements shall be determined by the city engineer.

<Code 1962, § 12-2-3(D))

Sec. 14-184. Pavement widths.

Roadway pavement widths shall be in accord ance with the urban street standards (see draw ing Nos. R-IA through R-IE on file in the city clerk's office). Alleys shall have a minimum pave ment width of twenty (20) feet.

<Code 1962, § 12-2-3(E))

Sec. 14-185. On-street parking.

On-street parking within the city rights-of-way shall be parallel only for all new development.

Off-street parking for vehicles shaH be provided as called for in section 27-453. Any proposed varia tions from the standard on-street parking provi sions must be approved by the city engineer.

(Code 1962, § 12-2-3(F))

Sec. 14-186. Bicycle ways.

Sec. 14-187. Landscaping.

Landscaping must be planned to contribute to safety. Landscaping must not create visual ob structions to motorists or pedestrians particularly at intersections and access points. No tree shall be located within two (2) feet of any street curb.

Low maintenance plantings are required. Plan ning of street landscaping shall give consideration t.o location of existing or proposed underground

Supp.No.4 utilities. For further landscaping requirements see section 26-16 et seq.

(Code 1962, § 12-2-3(H))

Sec. 14-188. Street lighting.

Street lighting and associated underground elec trical supply circuits are required for all streets in or on the periphery of all new developments.

Developers shall install a minimum of one (1) street light at every intersection. If a subdivision block length exceeds eight hundred (800) feet, one

(1) street light shall also be installed at midblock.

(Code 1962, § 12-2-3(1))

Sec. 14-189. Horizontal alignment of arterial streets.

{al Arterial streets shall be designed in accord ance with AASHTO "A Policy on Arterial High ways in Urban Areas." Collector and local road way curves should be designed with the following radius controls:

T.:vpe of street

Collector Local

Radiu.s control (feet!

400 minimum 200minimum

Local 125 where superelevation is practical

(b) There shall be a tangent at least one hun dred (100) feet long between reverse curves on all streets.

<Code 1962, § 12-2-3(JJ)

Sec. 14-190. Vertical road alignments.

(a) Vertical road alignments should relate to the natural topography insofar as is practical so as to minimize the need for cuts or fills while being consistent with safe geometric design.

(b) Arterial streets shall be designed in accord ance with AASHTO "A Policy on Arterial High ways in Urban Areas."

(c) All changes in roadway grade of greater than five-tenths of one (1) percent for arterials and one

(1) percent for local or collector streets shall be connected by parabolic curves of not less than one hundred (100) feet but of such length to provide for the following minimum stopping sight distances:

LOCAL PUBLIC IMPROVEMENT § 14-191

Stopping sight distance Type of street (in feet)

Arterial and collector 275 Local 200

(d) Grades for collector or local streets in com mercial or industrial areas shall not exceed six (6) percent. Grades for local residential streets should be as flat as is consistent with the surrounding terrain and shall be less than ten (10) percent.

Continuous change of grade so as to give a roller coaster effect shall not be permitted.

(e) In order to provide for proper drainage, the minimum grade to be used for roadways with gutters shall be three-tenths of one (1) percent.

Where grades of four (4) percent or steeper are necessary, an analysis of drainage inlet bypass and soil erosion in ditches or swales shall be per fonned and mitigation facilities provided as required.

(0 The gradient within one hundred (100) feet of any four-way street intersection shall not ex ceed five (5) percent. Every effort should be made to keep grades at street intersections as flat as possible and in all cases the required sight dis tances shall be provided. Three-way street inter sections shall have similar requirements unless circumstances warrant different grades as de tennined by the city engineer.

(g) All pavements on local or collector streets shall have a normal crown with a typical cross slope of three-hundredths foot per foot. Pavement cross-slope on local or collector streets at intersec tions or in special cases shall not exceed five hundredths foot per foot.

(h) Maximum side slopes between the curb and any existing or proposed structure shall not ex ceed one to one (1:1) on cuts or two to one (2:1) on fill areas. Side slopes between curb and right-of way lines shall not exceed the natural angle of repose as determined from analysis of soil conditions.

(Code 1962, § 12-2-3(K))

Sec. 14-191. Intersections.

(a) Streets shall be laid out so as to intersect at right angles, except where topography or other sight conditions justify variations. In no case shall the angle of intersections vary more than twenty

(20) degrees from a right angle. No intersection of public or private streets shall be on a curve of centerline radius less than five hundred (500) feet.

No curb cut will be allowed on a curve section of road whose inside curve radius is less than one hundred fifty (150) feet.

(b) Intersections shall be designed with adequate corner sight distance. Corner sight distances is defined as measured from a point on the center line of the right-hand travel lane of the minor road at least fifteen (15) feet from the edge of a major road pavement and measured from a height of eye of three and three-fourths (3%) feet on thE:

minor road to a height of object of four and one half(41h) feet on the centerline of the travel lanes of a major road. The corner sight distance for local and collector streets shall be a minimum of two hundred (200) feet. On arterial streets, corner site distance shall be three hundred fifty (350) feet. In addition to the corner sight distance re quirement, no fence, wall, entrance, hedge, shrub planting, tree or other sight obstruction greater than two and one-half (2lh) feet above the pave ment elevation shall be located within the trian gular area formed by curblines and line connect ing them at points thirty-five (35) feet from their point of intersection.

(c) Streets entering the opposite sides of a street shall either be directly across from each other or offset by at least one hundred twenty-five (125) feet from centerline to centerline.

(d) Streets shall not enter onto the same side of a street at intervals of less than three hundred

(300) feet from centerline to centerline.

(e) ~~orner radii at all inte:wjjom; sltaH-· he a mHH:m:tmt of twenty (29) f9;t --

(0 Street signs shall be provided by the devel oper at all intersections (see drawing number R-7 on file in the city clerk's office).

(g) Intersections which include collector or ar terial streets shall be designed to allow for futurt• traffic signalization. Geometry and all other de tails of these intersections shall be approved by the city engineer.

(Code 1962, § 12-2-3(L))

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§ 14-192 DURANGO CODE

Sec. 14-192. Storm drainage system.

The road system in most cases will be a pri mary element of the storm drainage collection system of a developed area. Wherever possible, road layouts and grades should be designed to avoid excessive runoff concentration and to min imize the need for storm sewers. Curbed road ways provide drainage outfall for adjacent prop erties and site grading generally should provide for runoff from sites toward the roadway. If major drainways exist or are proposed through a devel opment, the storm runoff should be routed to that drainway. All storm drainage system components shall be designed in accordance with the stand ards, policies and criteria of the city urban storm drainage master plan.

(Code 1962, § 12-2-3(M))

Sec. 14-193. Driveways and curb cuts.

Sec. 14-194. Sidewalks, curbs and gutters, cross pans.

(a) Sidewalks and curbs and gutters shall be constructed as shown on standard drawing no.

R-3 on file in the city clerk's office. Handicap ramps shall be installed at all intersections. Dif ference in top of curb elevations across any road way shall not exceed three-tenths feet except where required for superelevation of the roadway and at intersections.

(b) Roads shall be designed so that drainage is carried in concrete gutters. Road cross sections shall be so designed as to prevent sheet flow across roadways except where concrete cross pans are provided. Cross pans shall be constructed in ac cordance with standard drawing no. R-4 on file in the city clerk's office. Where storm drains are provided, no cross pans will be allowed. Cross pans are not allowed across collectors or arterials.

(c) Sidewalks will not be required on a side of a roadway which is not developable unless it is re quired to connect developed areas on the same side of the roadway.

(Code 1962, § 12-2-3(0))

Sec. 14-195. Cul-de-sac and dead-end streets.

) Dead-end streets are not allowed unless pr vxsxo are made for turning of emergency i cles. Tli' minimum pavements diameter fi turn-ing shall eighty (80) feet.

(b) Dead-en treets proposed to e extended to connect with fut ength of cui-de- c shall be five feet where the cui- -sac serves twenty ( or more units. Maximum ngths of one th and.(l,OOO) feet are permitted wh serv-ewer than twenty (20) units in reside eas.

(Code 1962, § 12-2-3(P))

Sec. 14-196. Pavement thickness.

(a) Unless substantiated by detailed structural design using the state, department of highways' roadway design manual or other acceptable de sign method, the following minimum compacted thickness of asphalt and aggregate base will be used:

Aggregate Asphaltic Aggregate base subbase concrete class 6 class 2

Type of street (inches) (inches) (inches)

Culs-de-sae and alleys 2 2 6

Local (residential traffic only) 2 4 6

LOCAL PUBLIC IMPROVEMENT § 14-200

Aggregate Asphaltic Aggregate base subbase concrete class 6 class 2

Type of street (inches} (inches) (inches)

Local (commercial and residential traffic) 3 4 6

Collector 4 8

Minor arterial (structural design required)

Major arterial (structural design required)

(b) On roadway projects exceeding four hundred

(400) lineal feet of pavement of public road, a pavement design based on soils analysis will be required.

(Code 1962, § 12-2-3(Q))

See. 14197. Water system standards generally.

All water distribution facilities installed within public rights-of-way or easements shall be con structed in accordance with the standard draw ings and constructed in accordance with the stan dard drawings and construction specifications of the city. In addition, all minimum standards of the state department of health shall be followed in the planning and construction of the water pumping, distribution and transmission facilities.

All water system construction plans shall be ap proved by the city engineer prior to beginning of any construction.

(Code 1962, § 12-24(A))

Sec. 14198. Waterlines.

(a) Water main extensions and replacements shall be a minimum of eight (8) inches in diame ter. Extensions to serve limited development may be served by a six-inch main where no potential exists for future development and where fire flow requirements can be met. Larger mains may be required in accordance with ISO firefighting re quirements or the city master water plan. All mains shall be extended to the furthest property line of any lot or development where future de velopment is at all possible. All waterlines shall be looped, if possible.

(b) Generally, waterlines will be located five

(5) feet south of the north curbline of east-west streets and five (5) feet west of the east curbline on north-south streets.

(c) Lines shall be installed with a minimum of four (4) feet of cover to the proposed or existing grade whichever may be less. The developer will be responsible to set grade stakes to ensure proper depth for all waterline installations.

(d) Waterlines shall be installed before paving or repaving of existing or proposed roads.

(Code 1962, § 12-2-4(13))

Sec. 14199. Valves.

(a) Three (3) gate valves are required at each main line tee except fireline.

(b) Any extensions to the end of property which cannot be looped shall be terminated with a gate valve at least nine (9) feeL in length of pipe and plug and thrust block.

(c) Air/vacuum release valves will be installed at all high points in transmission lines. Air re lease valves shall be installed in distribution sys tem lines as required by the city engineer.

(d) Gate valves shall be located so that no more than about seven hundred (700) feet of main line would be out of service due to a break anywhere in the main line. Flush valves shall be installed at all natural drainage crossings in accordance with the standard drawing.

(e) All-weather vehicular access shall be pro vided to each valve location.

(Code 1962, § 12-2-4(C))

Sec. 14200. Water pressure.

(a) Water shall be supplied to each building in any development at pressures not less than forty

(40) psi during peak consumption hours with all water tanks operating one-half full. Any devel opment unable to meet this requirement shall provide complete plans for a booster pump and tank system which shall be approved by the city engineer.

(b) Water shall be supplied in each development at pressures not exceeding one hundred ten (110) psi at any building under static conditions. Any

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development unable to meet this requirement must supply individual pressure reducing valves in ser vice lines to the buildings.

(c) In no case shall pressures in excess of one hundred eighty (180) psi be allowed in any main line under static conditions. A main line pressure reducing station shall be designed by the devel oper and approved by the city engineer for any development whose pressures would exceed the one hundred eighty (180J psi limit.

(Code 1962, § 12-2-4(D))

Sec. 14-201. Hydrants.

Hydrants shall be located in accordance with the Uniform Fire Code and shall be installed as shown in standard drawing no. W-1 on file in the city clerk's office. One (1) hydrant should be lo cated at the intersection of all streets. All hy drant locations are subject to approval by the director of fire services. Hydrant :tee, valves and waterline runs to the curbline shall be installed where potential development may occur along a street to be paved or repaved as a part of the development.

(Code 1962, § 12-2-4(E))

Sec. 14-202. Sewer line crossing.

(a) Should the condition exist where a sewer main must be constructed crossing above or below a water main, the minimum clear distance verti cally shall be six (6) inches.

(b) When sewer mains cross above water mains or within a vertical clear distance of eighteen (18) inches below water mains, the crossing must be constructed so as to protect the water main. (see drawing no. W-5 on file in the city clerk's office.)

(c) Minimum water main protection under these conditions shall consist of the installation of an impervious and structural sewer (e.g. vitrified clay or PVC, with concrete encasement, cast iron or ductile iron pipe) for a distance of ten (10) feet each side of the water main. In all cases, suitable backfill or other structural protection shall be provided to preclude settling or failure of the upper pipe.

(d) In no case shall a water main be located closer than ten (10) feet horizontally from a main sewer line unless the sewer line is of cast or duc tile iron construction.

(Code 1962, § 12-2-4(F))

Sec. 14-203. Water service lines.

(a) All buried service lines shall be of type K copper. Service lines including curb stop and box shall be installed from the main to the property line for each existing or proposed lot which is along a roadway to be paved as part of the im provement project. (see drawing no. W-7 on file in the city clerk's office.) Service line locations must be noted on construction plans and as-built drawings

(b) Separate service lines shall be supplied to each separately owned parcel of land. Townhomes and single-family dwellings shall have separate service lines to each dwelling unit. Condomini ums and apartments may be served by a common line to each building. Where two (2) or more com mercial buildings lie on a single parcel, each shall have a separate service line.

(Code 1962, § 12-2-4(G))

Sec. 14-204. Water service taps; fee.

(a) Tap fees and plant investment fees must be paid prior to any connection being made. The city water department will make service taps into all existing waterlines. The service line taps in all new main lines shall be made prior to pressuriz ing the water main.

(b) Main line connections must be approved and inspected by the city water superintendent.

(Code 1962, § 12-2-4(H))

Sec. 14-205. Sanitary sewer system standards generally .

All sewer collection and pumping facilities in stalled within public rights-of-way or easements shall be constructed in accordance with standard drawings and construction specifications of the city. In addition, all minimum standards of the state department of health shall be followed in planning and construction of wastewater pump ing and collection facilities. All sanitary sewer plans shall be approved by the city engineer prior to beginning construction.

(Code 1962, § 12-2-5(A))

LOCAL PUBLIC IMPROVEMENT § 14-211

Sec. 14-206. Slope of sewer lines.

(a) Minimum slopes of sewer lines shall be as follows:

Slope Type (percent)

4-inch service 6-inch service 8-inch main

10-inch main 12-inch main

1.0 1.0 0.5 0.4 0.3

(b) Larger mains shall be designed to transport average sewer flows at minimum mean velocities of two (2) feet per second under flowing full conditions.

(c) Maximum design velocity for sewers flow ing full shall not exceed ten (10) feet per second.

Slopes between manholes must be constant.

(Code 1962, § 12-2-5(B))

Sec. 14-207. Minimum pipe size.

Minimum pipe size for mains shall be eight (8) inches. Pipe shall be installed in accordance with line sizes recommended in the sanitary sewer mas ter plan. Where line sizes are not recommended in the master plan the city engineer will deter mine the appropriate line sizes.

(Code 1962, § 12-2-5(C))

Sec. 14-208. Location of sewer lines.

(a) Sewer lines shall be located generally on the centerline of streets but in no case shall main line sewer be located closer than ten (10) feet horizontally from the water main unless the sewer line is encased or of cast or ductile iron pipe. (see drawing no. W-5 on file at the city clerk's office).

Depth of sewer shall be at least three (3) feet from top of pipe to proposed or existing grade, which ever is lower.

(b) Deeper installation may be required by the city engineer to serve future growth. Structural design must be demonstrated for line to be laid deeper than ten (10J feet.

fc) Lines laid between manholes must be straight.

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(d) Sewer lines shall be extended to the far thest boundary of subdivisions or property being served where future development is possible. Sewer lines shall be installed before paving or repaving of existing or proposed roads.

(Code 1962, § 12-2-5(D))

Sec. 14-209. Manholes.

(a) Manholes shall be placed:

(1) At all changes in alignment;

(2) At all changes in grade;

(3) At intersections of two (2) or more main lines;

(4) At intervals no greater than four hundred

(400) feet along a main; and

(5) At the end of all mains (cleanouts on mains are not acceptable).

(b) Drop manholes shall be designed whenever elevation differences between any two (2) inverts is twenty-four (24) inches or greater. (see drawing

no. S-4, sheet 3 on file in the city clerk's office.)

(c) All manholes shall be accessible by grav elled access.

(Code 1962, § 12-2-5(E))

Sec. 14-210. Service lines.

Service lines shall not enter at manholes. Ser vice lines to eight (8) or more units in an apart ment or condominium building shall be six (6) inches. Separate service lines must serve each building on a parcel of land. Each parcel of land must have its own service lines. Service lines shall be extended to each lot or proposed lot line along any road which is to be paved or surfaced before paving occurs. Townhouses shall be served with individual four-inch service lines, one (1) to each unit.

(Code 1962, § 12-2-5(F))

Sec. 14-211. Force mains.

Minimum size of force mains shall be four (4) inches. Pipe shall be sized such that maximum velocity does not exceed six (6) feet per second.

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§ 14-211 DURANGDCODE

Force mains should be installed at a positive grade to a manhole where a gravity sewer line begins.

Where positive grades cannot be maintained, air and vacuum release valves must be installed at all relative high points in the line. Minimum depth for force mains shall be four (4) feet.

(Code 1962, § 12-2-5(G))

Sec. 14-212. Lift stations.

(a) Lift stations are discouraged. When neces sary, they shall be designed to serve an entire subbasin. All lift stations will be of the wet well/dry well design. (see drawing no. S-3 on file in the city clerk's office.) All designs are subject to approval of the city engineer, and in addition to meeting state health department criteria, shall include:

(1) Auxiliary alarm systems, with provisions for connection to the city's central alarm center by hardline telephone line;

(2) Auxiliary power supply (see state health department requirements);

(3) Control panel which provides for:

a. Automatic alternator for lead-lag oper· ation;

b. Automatic reset;

c. Hour meter for each pump motor;

d. Low voltage protection relays;

e. Running overload and high level lights;

f. HOA switch for each pump;

(4) Basket strainers that are easily accessible;

(5) Mercury bulb float switches;

(6) Auxiliary heaters and insulation in the dry well;

(7) Separate check and gate valves for each pump;

(8) Dry well sump pump or drain outlet;

(9) Epoxy paint coatings inside and outside for all metal surfaces. ·

(b) Wet and dry well lids should be twelve (12) inches above finished grade. Designs should state the consequence of power failure on the lift sta tion and population served by the lift station.

(Code 1962, § 12-2-5(H))

Sec. 14-213. Storm sewer system standards generally.

(a) All storm sewer collection facilities within public rights-of-way or easements shall be con structed in accordance with standard drawings and construction specifications of the city. In gen eral, storm sewers or surface drainage channels and culverts shall be installed when the carrying capacity of the street is exceeded based on the following chart:

ALLOWABLE USES OF STREETS

FOR DRAINAGE

Minor storm runoff (10-yearl

Stret!t Ckw- Maximum roadway

Major storm runoff (100-year)

(Allowable depth arul inundation) si/ication encroachment)

Local

Collector

Arterial

No curb overtopping;

where no curbing exists, encroachment shall not be over property lines.

Flow may spread to crown of street.

Inundation:

Residential dwellings, public, commercial and industrial buildings shall not be inundated at ground line, unless buildings are flood proofed. Depth of water over gutter flowline shall not exceed twelve

(12) inches.

No curb overtopping (Same as above) (same as above). Flow spread must leave at least one (1) ten-foot lane free of water.

No curb overtopping Inundation: (same as (same as above}. Flow above). Depth of water spread must leave at at street crown shall least one (1) ten-foot not el!XlE!E!d six (6) inches, lane free of water in to allow operation of each direction. emergency vehicles.

Depth of water flow line shall not exceed eigh· teen (18) inches.

(b) All storm sewer plans shall be approved by the city engineer prior to construction.

(Code 1962, § 12-2-6(A))

Sec. 14-214. Storm sewer pipe size.

(a) The minimum pipe size for storm sewers or culverts shall be twelve (12) inches nominal di ameter. Sizes required shall be as shown in the

LOCALPUBUCIMPROVEMENT § 14-235

urban storm drainage master plan. Where not covered in the master plan, storm drains shall be sized to transport the flow of a ten-year flood from the fully developed subbasin in which the devel opment lies to a natural drainage course or other point acceptable to the city engineer. Design pa rameters given in the master plan shall be used in the calculation of the ten-year flood from subbasins of less than two hundred (200) acres.

(b) For project sites of two hundred (200) acres or more, a method similar or equivalent to that identified in the Soil Conservation Service Proce dures for Determining Peak Flows in Colorado Technical Release No. 55 shall be used.

(c) Minimum depth of storm sewers from the top of pipe to finished grade shall be two and one-half (2¥.!) feet.

(Code 1962, § 12-2-6(B))

Sec. 14-215. Storm sewer slopes.

The minimum slope for storm sewers shall be such as to maintain a flowing full velocity of two and one-half (2¥.!) feet per second. Energy dissi paters must be installed in storm sewers where maximum velocity in the storm sewer would ex ceed ten (10) feet per second.

(Code 1962, § 12-2-6(C))

Sec. 14-216. Storm sewer inlets.

Inlets must be constructed in accordance with standard drawings at all locations necessary to prevent the sheet flow across paved road or pri vate property of a two-year flood. (see drawings numbered SS-2 through SS-4 on file in the city clerk's office.) Double inlets are required on all streets where gutter slopes exceed five (5) percent and as required by good design practice.

(Code 1962, § 12-2-6(0))

Sec. 14-217. Storm sewer outlets.

Outlets to Junction Creek and the Animas River shall be located above the ten-year flood level and shall be protected with a concrete headwall.

(Code 1962, § 12-2-6(E))

Sec. 14-218. Storm sewer manholes.

Manholes for storm sewers are required at:

(1) Change in grade;

(2) Change in alignment;

(3) Intersection of two (2) or more storm sew ers; and

(4) Intervals no greater than four hundred (400) feet for twenty-four (24) inches and small er, five hundred (500) feet for forty-eight

(48) inches and smaller, six hundred (600) feet for all others.

(Code 1962, § 12-2-6(F))

Sec. 14-219. Culverts.

(a) Culverts, where required, shall have twelve

(12) inches of cover under roads. Culverts shall begin and terminate with headwalls as shown in the standard drawing no. SS-7 on file in the city clerk's office.

(b) Culverts design shall be in accordance with the state department of highway's design manu

al. Capacity design calculations shall be submit ted along with plans for circular and box culvert design.

(c) No inverted siphons shall be permitted.

(Code 1962, § 12-2-6(G))

Sees. 14-220-14-234. Reserved.

DIVISION 3. CONSTRUCTION STANDARDS

FOR PUBLIC IMPROVEMENTS

Sec. 14-235. Approval, acceptance of plans.

Construction standards for streets and utilities as set forth in this division shall be followed in the design and construction of public facilities.

Two (2) prints of construction plans must be sub mitted for approval. All plans must be approved by the city engineer in writing. Once approved, plans will not be amended without approval of the city engineer. An improvements agreement between the city and owner must be entered into prior to construction of any public facilities. Ac-

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DURANGO CODE

ceptance of each phase of construction of public improvements (water, storm sewer, sanitary sewer, roads, etc.) is contingent upon:

(1) Submittal of approved as-built plans;

(2) Submittal of test results required as part of the city specifications; and

(3) A final inspection by the city engineer and the owners or their representatives. After final inspection, the city engineer shall in form the owner in writing of any deficien cies and whether or not a reinspection will be necessary. Reinspections by city person nel after the second inspection shall require an inspection fee to be paid by the owner pursuant to a schedule of fees adopted by resolution of the city council.

(Code 1962, § 12-1-2)

Sec. 14-236. Submission of construction plans-Roads.

(a) Road construction plans must be sufficiently complete to provide assurance of compliance with design standards. Plans must contain a statement that all facilities are to be installed in accordance with the latest revisions to the Standard Specifi cations for Construction of Streets and Roads. Ad ditionally, the plans or accompanying report must provide the following:

(1) Plan and profile of original grounds and design elevation of roadway centerline or each curbline;

(2) Design calculations and structural sections for pavement design, or minimum required section per city specifications;

(3) Approximate location of existing and pro posed underground utilities and exact lo cation by station of existing and proposed drainage structures and piping and profiles of any drainage piping under the proposed construction;

(4) Soil test report;

(5) Details of any road structures and street cross sections at fifty-foot intervals where side slopes exceed four to one (4:1) slope;

(6) Existing and proposed physical features within twenty (20) feet of the construction including geologically unstable areas, trees, cliffs, ponds, ditches and other topographic features;

(7) Right-of-way lines, easement lines, street names, one-hundred-year floodplain, bench marks, origin of survey, basis of bearing, section, township, range and professional engineer's seaL

(b) Construction plans should be provided in the same general format as preliminary improve ment plans are submitted per subdivision proce dures.

(c) As-built plans shall include all information required in the construction plans and shall pro vide additional or revised information when changes in horizontal alignment exceed three (3) feet or vertical alignment exceeds twenty-five hundredths (0.25) feet. If the standards are compromised or if public facilities are installed outside of public rights of-way or easements, as-built plans shall note the same. As-built plans shall be stamped by a pro fessional engineer certifying that facilities were installed in substantial accordance with approved plans.

(Code 1962, § 12-1-3)

Sec. 14-237. Same-Waterlines.

(a) Waterline construction plans must be suffi ciently complete to provide assurance of compli ance with design standards. Construction plans must contain the statement that all facilities are to be installed in accordance with the Standard Specifications for Construction of Waterlines, Sani tary Sewers and Storm Drainage Facilities. Addi tionally, the plans or accompanying report must provide the following:

(1) Maximum and minimum delivery pressures;

(2) Waterline profiles where slope exceeds fif teen (15) percent on any reach or where vertical fittings are proposed;

(3) Existing and proposed physical features within ten (10) feet of the waterline, in cluding trees, geologically unstable areas, LOCAL PUBLIC IMPROVEMENT § 14-239 cliffs, ponds, ditches and other topographic features;

(4) Pipe material, size and bedding class for all reaches of pipe, existing and proposed;

(5) Approximate location of proposed and ex isting utilities within twenty (20) feet of the proposed construction;

(6) Existing and proposed roads, sidewalk and curb lines;

(7) Right-of-way lines, easement lines, street names, one-hundred-year floodplain, bench marks, origin of survey, basis of bearing, section, township, range and professional engineer's seal.

(b) Construction plans should be provided in the same general format as are preliminary im provement plans submitted per the subdivision procedures.

(c) As-built plans shall include all information required in the construction plans and shall pro vide additional or revised information on location of valves, service lines, fittings, hydrants and water main lines. As-built plans shall be stamped by a professional engineer certifying that all facilities were installed in substantial accordance with the approved plans.

(Code 1962, § 12-1-4)

Sec. 14-238. Same-Sanitary sewers.

(a) Sanitary sewer construction plans must be sufficiently complete to provide assurance of com pliance with design standards. Construction plans must contain a statement that all facilities are to be installed in accordance with the Standard Speci fications for Construction of Waterlines, Sanitary Sewers and Storm Drainage Facilities. Addition ally, the plans or accompanying report must pro vide the following:

(1) Plan and profile, bearing, distance, size and grade of each reach, of sanitary sewer and force mains showing finished ground or pavement elevation and invert and rim el evations at each manhole;

(2) Existing and proposed lift stations with site details;

(3) Existing and proposed physical features within twenty (20) feet of the sewer line including geologically unstable areas, trees, cliffs, ponds, ditches and other topographic features;

(4) Pipe material, size and bedding class for all reaches of pipe, existing and proposed;

(5) Approximate location of proposed and ex isting utilities within twenty (20) feet of the sewer line;

(6) Existing and proposed roads, sidewalks and curb lines;

(7) Right-of-way lines, easement lines, street names, one-hundred-year floodplain, bench marks, origin of survey, basis of bearing, section, township, range and professional engineer's seal.

(b) Construction plans should be provided in the same general format as are preliminary im provement plans submitted per subdivision proce dures.

(c) As-built plans shall include all information required in the construction plans and shall pro vide additional or revised information when changes in horizontal alignment exceed one (1) foot or ver tical alignment exceeds one-tenth foot. If the stand ards are compromised or if public facilities are installed outside of public rights-of-way or ease ments, the as-built plans shall note the same.

As-built plans shall be stamped by a professional engineer certifying that facilities were installed substantially in accordance with approved plans.

(Code 1962, § 12-1-5)

Sec. 14-239. Same-Storm sewers.

(a) Storm sewer construction plans must be suf ficiently complete to provide assurance of compli ance with design standards.