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SWM-SY 990204Executive Summary Southwest Coppell Storm Water Management Master Plan z�-� , VO for 9 The City of Coppell NCH Coppell Industrial NV ���Halff Associates, Inc. February 4, 1999 NICHOLS, JACKSON, DILLARD, HAGER & SMITH, L.L.P. ROBERT L. DILLARD III Attorneys & Counselors at Law ROBERT E. HAGER 1800 Lincoln Plaza PETER G. SMITH 500 North Akard DAVID M. BERMAN BRUCE A. STOCKARD Dallas, Texas 75201 (214) 965 -9900 Fax(214)965 -0010 E -mail NJDHS @NJDHS.com March 22, 1999 Via Facsimile and First Class Mail Ken Griffin Director of Engineering City of Coppell 255 Parkway Boulevard P.O. Box 478 Coppell, Texas 75019 RE: DFW Airport Property; Drainage Dear Ken: JOHN F. ROEHM III JASON C. MARSHALL J. DAVID DODD III ROBERT L. DILLARD, JR. H. LOUIS NICHOLS LAWRENCE W. JACKSON OF COUNSEL �w-2a, ­73ga103 Pursuant to your request, the undersigned provides the following opinion regarding whether the City may adopt an ordinance to require detention or other drainage improvements for DFW Airport Board properly within the City of Coppell, Texas. The City may exercise exclusive regulatory authority of land within the City limits unless State law has preempted the City's authority. The Texas Legislature, however, has granted DFW Airport Board with an overriding control. Specifically, the Texas Transportation Code § 22.074(d) provides: "[A]nother local government or other political subdivision shall not enact or enforce a zoning ordinance, subdivision regulation, construction code, or any other ordinance purporting to regulate the use or development of property applicable within the geographic boundaries of the airport as it may be expanded." The Courts have held this language to clearly and unmistakably divest cities of their exclusive control over land within city limits that is also within the DFW Airport Board's geographic boundaries. Therefore, the City may not enact an ordinance requiring the construction of a detention pond within DFW Airport Board's geographic boundaries. You may, however, want to contact the appropriate officials at DFW Airport to discuss the potential drainage problems to ascertain if the DFW Airport Board has enacted regulations relating to drainage. w-a 4S ` Ken Griffin City of Coppell March 22, 1999 Page - 2 - Thank you for your attention to this matter. Please feel free to call if you have any questions regarding this or any other issue. Very truly yours, NICHOLS, JACKSON, DILLARD, HAGER & SMITH, L.L.P. By: Peter G. G. Smith SS24745 NICHOLS, JACKSON, DILLARD, HAGER & SMITH, L.L.P. SOUTHWEST COPPELL STORM WATER MANAGEMENT MASTER PLAN EXECUTIVE SUMMARY February 4, 1999 Introduction. This study examines storm water and drainage conditions in the southwestern portion of the City of Coppell. The project area is approximately bound by Coppell Road on the east, the Southern Pacific Railroad and LBJ Freeway on the south, the Dallas /Tarrant County Line on the west and Ruby Road and the Cottonwood Creek watershed on the north (Figure 1). The land uses in the area are mostly industrial although the extreme east end of the project area has been designated as "Historical" and has a mix of residential and commercial uses. Three large tracts of land remain to be developed; the NCH Tract (140 acres), the Coppell Ind. N. V. (CINV) Tract (100 acres) and a large tract of vacant land controlled by DFW International Airport west of Royal Lane and South of Bethel Road. In addition, a portion of the Minyard's site and the site just east of Freeport Parkway and south of Bethel Road remain to be developed. 9 1 NA FIGURE 1 PROJECT LOCATION E to Halff Associates 1 02/04/99 P=ose. In the study, alternatives are formulated to provide drainage through the project area sufficient for the future (built out) condition of the watershed. Costs for the various drainage infrastructure schemes are estimated and a plan is recommended. Existing Conditions. The project area is drained by Stream G1 (Old Town Creek), a tributary of Grapevine Creek. Stream G1 joins Grapevine Creek near the intersection of Bethel Road and Bethel School Road. At the downstream end of the project area, Coppell Road, Stream G1 has a total drainage area of 770 acres. In the downstream reaches of the project area, the channel is mostly natural between Coppell and Bethel Roads and the 100 -year flood plain encompasses many homes and businesses in the Historic District. The crossings at Coppell and Bethel Road are significantly overtopped by flood waters. Bethel Road traverses the project area in an east - west direction. Much of the upper watershed drainage originates on DFW Airport land and must travel via channels and storm sewers along Bethel Road between Royal Lane and Freeport Parkway through the project area. The sites south of Bethel Road between Royal Lane and Freeport Parkway (USPS and Minyards) are partially developed. The existing drainage system for Bethel Road consists of 1700 feet of open channel and 2000 feet of single box (5'x10') culvert and is undersized for the future (built out) condition of the watershed. Portions of the Minyards site remain to be developed. A small detention pond currently exists on the Minyards site and is included in the hydrologic computations for each alternative evaluated. Previous Studies. A City -Wide Storm Water Management Study prepared in 1991 by Halff Associates included drainage alternatives for a portion of the project area. The City -Wide Study recognized both the problems of substandard drainage upstream of Freeport Parkway and the lack of an adequate drainage path through residential areas at the north end of Loch Lane. This area is the outfall for drainage originating on the NCH and CINV tracts. The City -Wide Study suggested that the developers of these tracts be encouraged to include storm water detention in their drainage plans. Other City -Wide Storm Water Management Study recommendations for Stream G1 in the project area included channel improvements between Coppell and Bethel Roads, a new bridge at Coppell Road, new culverts at Bethel Road and erosion control just downstream of Coppell Road. These drainage improvements were estimated at $1,036,000 (1990 dollars). The hydrologic and hydraulic computations in this study are based on the information developed for the City -Wide Storm Water Management Study with detail added to analyze storm water flows in the upper Stream G1 watershed as shown on the attached drainage area map. Storm Water Management Alternatives. An array of storm water management alternatives were considered for the project area. The feasible alternatives explored in detail were site detention, regional detention, conventional underground storm sewer systems and combinations of detention and conventional underground storm sewer systems. The site detention basins are sized to retain sufficient storm water so that the release from the basin does not exceed that which would occur from the site in its pre- developed condition. This detention concept has proven to be a fair, equitable and defensible criteria for sizing detention basins in municipalities such as Dallas, Denton and Austin. The regional detention basin is sized for the maximum discharge reduction practicable in a single facility. Hydrologic and hydraulic summary information is attached at the end of this executive summary. Halff Associates 2 02/04/99 Alternative I (Conventional Drainage). A conventional underground storm sewer system was developed for the NCH and CMV sites and for the drainage in Bethel Road. The schematic layout and sizes of the proposed drainage system is shown on the attached Sheet 1. The estimated cost of this alternative is $2,769,000 for the NCH site, $174,000 for the CINV site, $1,406,000 for the outfall from NCH and CINV, $19,000 for the park site and $4,565,000 for Bethel Road for a total project cost of $8,933,000. Alternative 2 (Detention /'Bethel Road Storm Sewer). Storm water detention was evaluated as a means to reduce downstream drainage requirements for Bethel Road and for both the NCH and CINV sites. In this alternative, detention basins were proposed on the DFW Airport property at the corner of Royal and Bethel and for the CINV and NCH site. Even with detention, storm sewer improvements are still necessary for Bethel Road. The schematic layout and sizes of the detention ponds and proposed drainage system is shown oil tt att�cl}ed Sheet 2. The estimated cost of this alternative is 1,350,000 for the NCH site (3.1 ad Mention pond), $485,000 for the CINV site (2.5�acre detention pond), $540,000 for the NCH /CINV outfall, $2,265,000 for the DFW Airport site (14 acre detention pond )$19,000 for the park site and $3,258,000 for Bethel Road for a total project cost of $7,917,000. 800, y Alternative 3 (Detention /Bethel Road Open Channel). This alternative is identical to Alternative 2 except that the Bethel Road drainage is served by an open channel instead of underground storm sewer. The schematic layout and sizes of the detention ponds and proposed drainage system is shown on the attached Sheet 3. The estimated cost of this alternative is $1,562,000 for the NCH site, $560,000 for the CEW site, $540,000 for the NCHXRNV outfall, $2,265,000 for the DFW Airport site, $19,000 for the park site and $1,014,000 for Bethel Road for a total project cost of $5,960,000. Alternative 4 (Linear Detention /New East -West Road). This alternative is identical to Alternative 3 except that the drainage and detention on the NCH and CINV sites is incorporated into the median of a proposed new east -west road as a linear detention system. The schematic layout and sizes of the proposed detention and drainage system is shown on the attached Sheet 4. A typical section is also attached. The estimated cost of this alternative is $801,000 for the NCH site, $704,000 for the CINV site, $540,000 for the NCH/CINV outfall, $2,265,000 for the DFW Airport site, $19,000 for the park site and $1,105,000 for Bethel Road for a total project cost of $5,434,000. Alternative 5 (Regional Detention). In this alternative, a large, regional detention pond is proposed for the DFW Airport site. The goal of this pond is to reduce storm water discharges in Bethel Road to a level that can be handled by the existing system. This would eliminate detention requirements for the remaining undeveloped sites in the project area. However, each site would contribute to the construction of the regional qqt ionzb�n on an equitable basis. As depicted on Sheet 5, the regional detention facility requires 32 acres of land and has an estimated $5,173,000 cost (construction and land). The total drainage cost (including conventional drainage for the NCH and CINV sites) for this alternative is $10,204,000. Halff Associates 3 02/04/99 Offsite Alternatives. The costs for underground drainage improvement between the NCH east property line and Stream G1 is shown in Table 1 in the row labeled Offsite ($540,000). If the three homes in this area are purchased and the proposed underground outfall system is replaced with an open channel, the cost of the land and improvements and the channel (Table 7) is a slightly cheaper alternative at $515,000. Historic District Drainage Features. The alternatives discussed above have impacts on Stream G1 through the Historic District. Alternative 1, Conventional Drainage will require channelization and structures for Bethel and Coppell Roads as per the City -Wide Storm Water Management Study prepared in 1991. For Alternatives 2 through 4, the channelization can be greatly reduced along with the size of the structures as seen on the respective sheets. The cost of these features is estimated at $900,000. Alternative 5, Regional Detention, is similar to Alternates 2 through 4, but actually requires more channelization to make the Bethel Road storm sewer function properly. Costs. A drainage cost comparison summary is shown on Table 1. Details of each alternative's cost estimate is included as Tables 2 through 6. A summary of land dedication requirements for Alternatives 3 and 4 is also attached. Land costs for transportation requirements are not included in the drainage alternative cost estimates. Conclusions. Alternative 4 is the most efficient, cost effective and equitable solution for the project area. It is the cheapest alternative by approximately $530,000. It also is the most efficient alternative in terms of street and drainage ROW requirements. The abandonment of a portion of existing Bethel Road benefits the adjoining landowners and helps discourage truck traffic through the neighborhoods to the east. Alternative 4 is also the most equitable alternative in that mall owners of undeveloped land have similar cost impacts and a uniform detention policy is applied to these owners. Alternative 3, which retains Bethel Road in its current alignment, is the next least costly. Both of these alternatives result in no increase in flood levels or erosive velocities through the downstream reaches of Stream G1. Conventional drainage is by far the most expensive of the first four alternatives and will increase flooding and erosion in downstream reaches of Stream G1 as compared to the current (1999) condition. The regional detention alternative for the Airport land west of Royal Lane is the most expensive of all the alternatives and offers no overall benefits to the area as a whole. In all alternatives evaluated, the existing detention facility serving the Minyards site should be retained. Recommendations. The City of Coppell should adopt the Linear Detention with New East/West Road Plan (Alternative 4) as the Storm Water Master Plan for Southwest Coppell. Halff Associates 4 02/04/99 �Q O a;o O Q QQQ O O O O O O O O 69 O o° Q Z Z. O Z Z Z Z O W ti LO ti � CD CMO _L � ti LO T- 69 O LO U) N 1 Lf') 6� O LL LL 6�} 0 O O O O O O O O O O O O O O O O O O O O O 69 O O Ln 0 O O O O O O k ti O ti � CD CMO O J ti T- 69 O N Q N 1 Lf') 6� O 6�} O O O O O O O O O O CD O O O O O O (D O� O M JO f` O 00 d' LO � N 69 60- O It Q 69 69 61!? N 1 Ld 69 6F} 6F} O CD CD CD CD H co O O O O O O O O O O O O O O O ' w O C O N CO d' E CO � (D O- � O J Lr) LO LO N UY 69 CY) O) pa Q 69 69 N Lf') Q d CD CD CD CD CD CD CD CD O CD CD O O O CD O O O O LO � G � � J 000 M It LC) N 69 69 CEO — Q 6a} - 69 CV M f` 6F? 69 6F} 6F} O CD O CD CD O O O O O O O O O O O O F- ti O� CD O LN C'7 N "Zi 69 6+g �} Z >- O LLL L ? 0 W J 0 W m = J Z = = W Q H O (.) Z Q 0 m TABLE 2 DRAINAGE ALTERNATIVE #1 CONVENTIONAL DRAINAGE - NO DETENTION ESTIMATED COST FOR DRAINAGE IMPROVEMENTS NORTH OF BETHEL CINV: 2 -24" REINFORCED CONCRETE PIPE (RCP) OUTLET STRUCTURES: SUBTOTAL: $139,000 25% CONTINGENCY: $35,000 TOTAL CINV: $174,000 NCH: 4 -10x5 BOX CULVERTS: 6 -10x5 BOX CULVERTS: OUTLET STRUCTURES: SUBTOTAL: $2,215,000 25% CONTINGENCY: $554,000 TOTAL NCH: $2,769,000 OFFSITE: 6 -10x5 BOX CULVERTS: OUTLET STRUCTURES: 70' DRAINAGE EASEMENT: SUBTOTAL: $1,125,000 25% CONTINGENCY: $284,000 TOTAL OFFSITE: $1,406,000 PARK: DETENTION EXCAVATION: SUBTOTAL: $15,000 25% CONTINGENCY: $4,000 TOTAL OFFSITE: $19,000 SOUTH OF BETHEL USPS: ADDITIONAL CHANNEL EXCAVATION ADDITIONAL LAND FOR CHANNEL: SUBTOTAL: $121,700 25% CONTINGENCY: $30,300 TOTAL USPS: $152,000 1550 L.F. @ $80 /LF = $124,000 1 EA @ $15,000/EA = $15,000 1450 L.F. @ $1000 /LF = $1,450,000 500 L.F. @ $1500 /LF = $750,000 1 EA @ $15,000/EA = $15,000 700 L.F. @ $1500 /LF = $1,050,000 1 EA @ $15,000/EA = $15,000 1.1 ACRES @ $54,450/Ac = $59,900 3,007 C.Y. @ $5 /CY = $15,000 12,360 C.Y. @ $5 /CY = $61,800 1.1 ACRES @ $54,450/Ac = $59,900 MINYARDS: 7 -10x5 BOX CULVERTS: OUTLET STRUCTURE: SUBTOTAL: $3,530,000 25% CONTINGENCY: $883,000 TOTAL MINYARDS: $4,413,000 2000 L.F. @ $1,750 /LF = $3,500,000 2 EA @ $15,000/EA = $30,000 TOTAL ALTERNATIVE #1: $8,933,000 TABLE 3 DRAINAGE ALTERNATIVE #2 "SITE" DETENTION - IMPROVE BETHEL DRAINAGE WITH CHANNELS AND CULVERTS ESTIMATED COST FOR DRAINAGE IMPROVEMENTS NORTH OF BETHEL CINV: DETENTION EXCAVATION 22,514 C.Y. @ $5 /CY = $112,600 ADDITIONAL AREA FOR DETENTION: 2.5 ACRES @ $54,450/Ac = $136,200 2- 24" RCP 1550 L.F. @ $80 /LF = $124,000 OUTLET STRUCTURES: 1 EA @ $15,000/EA = $15,000 SUBTOTAL: $387,800 25% CONTINGENCY: $97,200 TOTAL CINV: $485,000 NCH: DETENTION EXCAVATION: ADDITIONAL AREA FOR DETENTION 2 -10x5 BOX CULVERTS: OUTLET STRUCTURES: SUBTOTAL: $1,080,200 25% CONTINGENCY: $269,800 TOTAL NCH: $1,350,000 OFFSITE: 3 -10x5 BOX CULVERTS: OUTLET STRUCTURES: 40 FOOT EASEMENT: SUBTOTAL: $432,200 25% CONTINGENCY: $107,800 TOTAL OFFSITE: $540,000 PARK: DETENTION EXCAVATION: SUBTOTAL: $15,000 25% CONTINGENCY: $4,000 TOTAL OFFSITE: $19,000 SOUTH OF BETHEL AIRPORT: DETENTION EXCAVATION: ADDITIONAL AREA FOR DETENTION SUBTOTAL: $1,812,000 25% CONTINGENCY: $453,000 TOTAL AIRPORT: $2,265,000 31,281 C.Y. @ $5 /CY = $156,400 3.1 ACRES @ $54,450/Ac = $168,800 1450 L.F. @ $500/LF = $725,000 2 EA @ $15,000 /EA = $30,000 500 L.F. @ $750 /LF = $375,000 2 EA @ $15,000/EA = $30,000 0.5 ACRES @ $54,450/Ac = $27,000 3,007 C.Y. @ $5 /CY = $15,000 210,000 C.Y. @ $5 /CY = $1,050,000 14 ACRES @ $54,450/Ac = $762,000 USPS: ADDITIONAL CHANNEL EXCAVATION ADDITIONAL AREA FOR CHANNEL: SUBTOTAL: $75,800 25% CONTINGENCY: $19,200 TOTAL USPS: $95,000 MINYARDS: 5 -10x5 BOX CULVERTS: OUTLET STRUCTURES: SUBTOTAL: $2,530,000 25% CONTINGENCY: $633,000 TOTAL MINYARDS: $3,163,000 7,557 C.Y. @ $5 /CY = $37,800 0.7 ACRES @ $54,450/Ac = $38,000 2000 L.F. @ $1,250 /LF = $2,500,000 2 EA @ $15,000 /EA = $30,000 TOTAL ALTERNATIVE #2: $7,917,000 TABLE 4 DRAINAGE ALTERNATIVE #3 "SITE" DETENTION - IMPROVE BETHEL DRAINAGE WITH CHANNELS ESTIMATED COST FOR DRAINAGE IMPROVEMENTS NORTH OF BETHEL CINV: DETENTION EXCAVATION 22,514 C.Y. @ $5 /CY = $112,600 ADDITIONAL AREA FOR DETENTION: 2.5 ACRES @ $54,450/Ac = $136,200 2- 24" RCP 1550 L.F. @ $80 /LF = $124,000 OUTLET STRUCTURES: i EA @ $15,000 /EA = $15,000 ADDITIONAL LAND FOR BETHEL CHANNEL: 0.7 ACRES @ $54,450/Ac = $38,100 BETHEL CHANNEL EXCAVATION: 4,380 C.Y. @ $5 /CY = $21,900 SUBTOTAL: $447,800 25% CONTINGENCY: $112,200 TOTAL CINV: $560,000 NCH: DETENTION EXCAVATION: 31,281 C.Y. @ $5 /CY = $156,400 ADDITIONAL AREA FOR DETENTION: 3.1 ACRES @ $54,450/Ac = $168,800 2 -10x5 BOX CULVERTS: 1450 L.F. @ $500/LF = $725,000 OUTLET STRUCTURES: 2 EA @ $15,000 /EA = $30,000 ADDITIONAL LAND FOR BETHEL CHANNEL: 1.6 ACRES @ $54,450/Ac = $92,600 BETHEL CHANNEL EXCAVATION: 15,298 C.Y. @ $5 /CY = $76,500 SUBTOTAL: $1,249,300 25% CONTINGENCY: $312,700 TOTAL NCH: $1,562,000 OFFSITE: 3 -10x5 BOX CULVERTS: OUTLETSTRUCTURES: 40 FOOT EASEMENT: SUBTOTAL: $432,200 25% CONTINGENCY: $107,800 TOTAL OFFSITE: $540,000 PARK: DETENTION EXCAVATION: SUBTOTAL: $15,000 25% CONTINGENCY: $4,000 TOTAL OFFSITE: $19,000 SOUTH OF BETHEL AIRPORT: DETENTION EXCAVATION: ADDITIONAL AREA FOR DETENTION SUBTOTAL: $1,812,000 25% CONTINGENCY: $453,000 TOTAL AIRPORT: $2,265,000 500 L.F. @ $750 /LF = $375,000 2 EA @ $15,000/EA = $30,000 0.5 ACRES @ $54,450/Ac = $27,200 3,007 C.Y. @ $5 /CY = $15,000 210,000 C.Y. @ $5 /CY = $1,050,000 14 ACRES @ $54,450/Ac = $762,000 USPS: ADDITIONAL CHANNEL EXCAVATION ADDITIONAL AREA FOR CHANNEL: SUBTOTAL: $75,800 25% CONTINGENCY: $19,200 TOTAL USPS: $95,000 MINYARDS: 5 -10x5 BOX CULVERTS: OUTLETSTRUCTURES: ROAD REPAIR: SUBTOTAL: $735,000 25% CONTINGENCY: $184,000 TOTAL MINYARDS: $919,000 7,557 C.Y. @ $5 /CY = $37,800 0.7 ACRES @ $54,450/Ac = $38,000 525 L.F. @ $1,250/LF = $655,000 4 EA @ $15,000 /EA = $60,000 2 EA @ $10,000/EA = $20,000 TOTAL ALTERNATIVE #3: $5,960,000 TABLE 5 DRAINAGE ALTERNATIVE #4 LINEAR DETENTION - RELOCATE BETHEL ESTIMATED COST FOR DRAINAGE IMPROVEMENTS NORTH OF BETHEL CINV: CHANNEL EXCAVATION: 23,644 C.Y. @ $5 /CY = $118,200 ADDITIONAL AREA FOR CHANNEL: 3.6 ACRES @ $54,450/Ac = $196,000 2 -10x5 BOX CULVERTS: 100 L.F. @ $500 /LF = $50,000 2- 24" RCP 1550 L.F. @ $80 /LF = $124,000 OUTLET STRUCTURES: 5 EA @ $15,000 /EA = $75,000 SUBTOTAL: $563,200 25% CONTINGENCY: $140,800 TOTAL CINV: $704,000 NCH: CHANNEL EXCAVATION: 33,833 C.Y. @ $5 /CY = $169,200 ADDITIONAL AREA FOR CHANNEL: 3.7 ACRES @ $54,450/Ac = $201,500 3 -10x5 BOX CULVERTS: 220 L.F. @ $750 /LF = $165,000 OUTLET STRUCTURES: 7 EA @ $15,000 /EA = $105,000 SUBTOTAL: $640,700 25% CONTINGENCY: $160,300 TOTAL NCH: $801,000 OFFSITE: 3 -10x5 BOX CULVERTS: 500 L.F. @ $750 /LF = $375,000 OUTLET STRUCTURES: 2 EA @ $15,000 /EA = $30,000 25' DRAINAGE EASEMENT: 0.5 ACRES @ $54,450/Ac = $27,200 SUBTOTAL: $432,200 25% CONTINGENCY: $107,800 TOTAL OFFSITE: $540,000 PARK: DETENTION EXCAVATION: 3,007 C.Y. @ $5 /CY = $15,000 SUBTOTAL: $15,000 25% CONTINGENCY: $4,000 TOTAL OFFSITE: $19,000 SOUTH OF BETHEL AIRPORT: DETENTION EXCAVATION: 210,000 C.Y. @ $5 /CY = $1,050,000 ADDITIONAL AREA FOR DETENTION: 14 ACRES @ $54,450/Ac = $762,300 SUBTOTAL: $1,812,000 25% CONTINGENCY: $453,000 TOTAL AIRPORT: $2,265,000 LISPS: CHANNEL EXCAVATION: 7,557 C.Y. @ $5/CY = $37,800 ADDITIONAL AREA FOR CHANNEL: 0.7 ACRES @ $54,450/Ac = $38,100 SUBTOTAL: $75,900 25% CONTINGENCY: $19,100 TOTAL USPS: $95,000 OLD BETHEL: CHANNEL EXCAVATION: ADDITIONAL AREA FOR CHANNEL: ROAD REPAIR: 5 -10x5 BOX CULVERTS: OUTLET STRUCTURES: SUBTOTAL: $808,300 25% CONTINGENCY: $201,700 TOTAL OLD BETHEL: $1,010,000 TOTAL ALTERNATIVE # 4: $5,434,000 23,350 C.Y. @ $5 /CY = $116,800 0.9 ACRES @ $54,450/Ac = $49,000 2 EA @ $10,000 /EA = $20,000 450 L.F. @ $1,250/LF = $562,500 4 EA @ $15,000 /EA = $60,000 TABLE 6 DRAINAGE ALTERNATIVE #5 CONVENTIONAL DRAINAGE - REGIONAL DETENTION ESTIMATED COST FOR DRAINAGE IMPROVEMENTS NORTH OF BETHEL CINV: 2- 24" RCP 1550 L.F. @ $80 /LF = $124,000 OUTLET STRUCTURES: 1 EA @ $15,000 /EA = $15,000 SUBTOTAL: $139,000 25% CONTINGENCY: $35,000 TOTAL CINV: $174,000 NCH: 4 -10x5 BOX CULVERTS: 1450 L.F. @ $1000 /1,17 = $1,450,000 6 -10x5 BOX CULVERTS: 500 L.F. @ $1500 /LF = $750,000 OUTLET STRUCTURES: 1 EA @ $15,000 /EA = $15,000 SUBTOTAL: $2,215,000 25% CONTINGENCY: $554,000 TOTAL NCH: $2,769,000 OFFSITE: 6 -10x5 BOX CULVERTS: 700 L.F. @ $1500 /LF = $1,050,000 OUTLET STRUCTURES: 1 EA @ $15,000/EA = $15,000 70' DRAINAGE EASEMENT: 1.1 ACRES @ $54,450/Ac = $59,900 SUBTOTAL: $1,125,000 25% CONTINGENCY: $281,000 TOTAL OFFSITE: $1,406,000 PARK: DETENTION EXCAVATION: 3,007 C.Y. @ $5 /CY = $15,000 SUBTOTAL: $15,000 25% CONTINGENCY: $4,000 TOTAL OFFSITE: $19,000 SOUTH OF BETHEL AIRPORT: DETENTION EXCAVATION: 490,000 C.Y. @ $5 /CY = $2,450,000 ADDITIONAL AREA FOR DETENTION: 31 ACRES @ $54,450/Ac = $1,688,000 SUBTOTAL: $4,138,000 25% CONTINGENCY: $1,035,000 TOTAL AIRPORT: $5,173,000 MINYARDS: 1 -10x5 BOX CULVERTS: OUTLET STRUCTURE: SUBTOTAL: $530,000 25% CONTINGENCY: $133,000 TOTAL MINYARDS: $663,000 TOTAL ALTERNATIVE #5: $10,204,000 2000 L.F. @ $250 /LF = $500,000 2 EA @ $15,000 /EA = $30,000 TABLE 7 OFFSITE DRAINAGE ALTERNATIVE PURCHASE PROPERTY EAST OF NCH ESTIMATED COST FOR DRAINAGE IMPROVEMENTS 601 LOCH LANE PURCHASE: 600 LOCH LANE PURCHASE: 604 LOCH LANE PURCHASE: CHANNEL EXCAVATION: SUBTOTAL: $411,000 25% CONTINGENCY: $104,000 TOTAL OFFSITE: $515,000 $100,000 $100,000 $150,000 12,360 C.Y. @ $5 /CY = $61,800 Table 8 LAND DEDICATION SUMMARY FOR SOUTHWEST COPPELL STORM WATER MANAGEMENT MASTER PLAN (EVALUATION FOR ALTERNATIVES 3 & 4 ONLY) *- �Go rn ALT.3 NCH = CINV OFFSITE PARK IMINYARDI LISPS AIRPORT DETENTION LAND 3.1 2.5 0.0 0.5 0.0 0.0 14.0 DETENTION / CONVEYANCE 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CONVEYANCE 1.6 0.7 0.5 0.0 0.0 0.7 0.0 TRANSPORTATION 9.7 1.6 0.0 0.0 0.0 0.0 0.0 TOTAL 14.41 4.81 0.51 0.51 0.01 0.71 14.0 DETENTION LAND 0.0 0.0 0.0 0.5 0.0 0.0 14.0 DETENTION/ CONVEYANCE 3.7 3.6 0.0 0.0 0.0 0.0 0.0 CONVEYANCE 1 0.0 0.0 0.5 0.0 0.9 0.7 TRANSPORTATION 10.8 3.91 0.01 0.01 0.01 0.01 0.0 TOTAL 14.5 7- 7.51 0.51 0.51 0.91 0.71 14.0 *ALL QUANTITIES ARE IN ACRES N I 0 25 50 75 100 150 200 300 SCALE IN FEET SCALE: V = 1000' CITY OF COPPELL TOPOGRAPHIC MAPPING BY DALLAS AERIAL SURVEYS AND BY TEAGUE NALL AND PERKINS CONSULTING ENGINEERS, UPDATED 1998. GRID COORDINATE VALUES ARE BASED ON THE 11 l i1 IJ COPPELL INL, STREAM G-I a ROYAL LANE TOTAL DRAINAGE AREA = 243 ACRES oInt) = 1633 r.Pq PRE EVE OPMENT (IQqR) TEXAS STATE COORDINATE SYSTEM, 0160 z 2237 CFS ULTIMATE DEVELOPMENT. NORTH CENTRAL ZONE-NAD '83. ADDITIONAL TOPOGRAPHIC MAPPING FROM DFW AIRPORT M88 FILES WSTING 8-8'X4 j A iN L e 4 Ov 211-w - . ...... 4 B r J lei 1 �2 LVERT,S VXISTING -1 FILOT ,.HANNEL e� I CHANNEL cnra mu, w no BOX CU14,"VERT OX 4� I Rio 8 -8'X5' too BETIM ROAD mwJ ;iI4A RDS —z" N 4A 14% 490 —STREAM G-I m COPPELL ROAD 98 ACRES TOTAL DRAINAGE AREA 710 ACRES LOPMENT (1998) E DEVELOPME14T 0100 = 3308 CFS PREDEVELOPMENT (199B) 0100 =4405 CFS ULTIMATE DEVELOPMENT wl mgr iaL 4q vo 1 40 r LXIS 2-9 'G, " il' A� R ESOX CL' Qrx 5 A CO.P1 FLL U. S. POSTAL ` 0m, EXXST BG% X SERVIC9 EXISTING PER z CULVERT DETENT!ON. POND (�%D3 tL --d 0� STREAM G-I a FREEP ORT TOTAL DRAINAGE AREA = 410 ACRES 0100 = 1812 CFS PREDEVELOPMENT (1998) 0100 = 2510 CFS ULTIMATE DEVELOPMENT N, o� STREAM G-1 a BETHEL RD 7 [:TOTAL DRAINAGE AREA = 460 ACRES DI Otoo _ _ 2 011137 CFS PREDEVELOPMENT (1998) r!b 00 . DO it 00 Go 2591 CFS ULTIMATE DEVELOPMENT Bugg A La gOU.jffW"$7MN' BLVD, EXHIBIT A DRAINAGE AREA MAP STREAM G-1 STORM WATER MANAGEMENT MASTER PLAN NCH — CITY OF COPPELL COPPELL, TEXAS ON Halff Associates 000 ENGINEERS . ARCHITECTS . SCIENTISTS . PLANNERS . SURVEYORS ORAWN DATE SCALE NOTES FILE CARD FEBRUARY AS AVO 1999 SHOWN 17582 5820SCH2 V, r amp, IJ COPPELL INL, STREAM G-I a ROYAL LANE TOTAL DRAINAGE AREA = 243 ACRES oInt) = 1633 r.Pq PRE EVE OPMENT (IQqR) TEXAS STATE COORDINATE SYSTEM, 0160 z 2237 CFS ULTIMATE DEVELOPMENT. NORTH CENTRAL ZONE-NAD '83. ADDITIONAL TOPOGRAPHIC MAPPING FROM DFW AIRPORT M88 FILES WSTING 8-8'X4 j A iN L e 4 Ov 211-w - . ...... 4 B r J lei 1 �2 LVERT,S VXISTING -1 FILOT ,.HANNEL e� I CHANNEL cnra mu, w no BOX CU14,"VERT OX 4� I Rio 8 -8'X5' too BETIM ROAD mwJ ;iI4A RDS —z" N 4A 14% 490 —STREAM G-I m COPPELL ROAD 98 ACRES TOTAL DRAINAGE AREA 710 ACRES LOPMENT (1998) E DEVELOPME14T 0100 = 3308 CFS PREDEVELOPMENT (199B) 0100 =4405 CFS ULTIMATE DEVELOPMENT wl mgr iaL 4q vo 1 40 r LXIS 2-9 'G, " il' A� R ESOX CL' Qrx 5 A CO.P1 FLL U. S. POSTAL ` 0m, EXXST BG% X SERVIC9 EXISTING PER z CULVERT DETENT!ON. POND (�%D3 tL --d 0� STREAM G-I a FREEP ORT TOTAL DRAINAGE AREA = 410 ACRES 0100 = 1812 CFS PREDEVELOPMENT (1998) 0100 = 2510 CFS ULTIMATE DEVELOPMENT N, o� STREAM G-1 a BETHEL RD 7 [:TOTAL DRAINAGE AREA = 460 ACRES DI Otoo _ _ 2 011137 CFS PREDEVELOPMENT (1998) r!b 00 . DO it 00 Go 2591 CFS ULTIMATE DEVELOPMENT Bugg A La gOU.jffW"$7MN' BLVD, EXHIBIT A DRAINAGE AREA MAP STREAM G-1 STORM WATER MANAGEMENT MASTER PLAN NCH — CITY OF COPPELL COPPELL, TEXAS ON Halff Associates 000 ENGINEERS . ARCHITECTS . SCIENTISTS . PLANNERS . SURVEYORS ORAWN DATE SCALE NOTES FILE CARD FEBRUARY AS AVO 1999 SHOWN 17582 5820SCH2 CONVENTIONAL DRAINA GE - NO DE T EN TI ON r• 544'.5 Fi 4.?Ai P X N 5_O.G x: r. rxaram �"'! 52oa x x IN 7,-36M lip _ i Ys — 52:3,9 f' ...... �..... �` x PARK . ,..... ,.... ...... . , .....,,» . ..... ..............F:: ;......,...,,... ...... ..............,...,.... :,...... ....,...,...,........ ...,., #,,,. _ : ::.................::::::::: :::.... DETENTIO : i ...............! :;.$ri ... :: - r �v. [EW EXTE — N f .......... .......... ». ......,,. » ».. »,,...,.» F. » »..,... „ ...,» .. ,,,,,,,,,,,,,,, , i.. i .. ....... . ...... , tF ....... ........ . ,..,,..,.., » »» .., .. .• .................�... ,........ ». », DFW AIRPORT ; Y. �,. 5,5,......,.. .,..........•.... ....... ................ ... .,.. , ..:i..................... .............,....... ..,..............,......,.,..., € , • .. , r? ...... ...,,.l.... ,..... ........ »..» ..... s F., j U.S.P.S. ......k....,.. ........7:.... .. 9 ........................ k W ...F ................ wit .........:::::: �:....................... ..:......... »�.........;. ......3:::................,,., os - F. ,..5 k ' %iazi•ir" w t.. .....: :: : ;:::� ;:� :: :: .. .::................... . ::::: ::::::::::::: ::: ....... ......F:: : ::::::� ::::iii::;:......,., .......,. ........,.,,,...,................. ..,,...,....,.............,•... ....,,... .........,.»:':::;::: :: ; ^:^ .;..:::::;::iii }� "si #i #ii # #tiiiiits sosccL:.$.... » »,...•..,...... ^� .. ...............i.... .................. .................. ......... .......... N.C.H. ...... .... .. ..... ............ ......{ g;,,,.....,, �.... £k?SY...,,,,.,...,,,...,,, . ..................,. ....,..... °..... ».. a r. $,.,.. ».,,.......... it ::......................:: i:: :... ...............: •:::::........ s ................. ............................... ......... S '....,,.,...............•... . r ........................... ,. ...., .... .......... i ............................ 1 ..,. {....,.......... ii... ......................,,.....,, , .. ...........3 ............ .. l...... .,, r ............................... s...,.........,,..,,,,.,,...... » »...s ....:::. . ......... ::riiis ; iii:::::::::.. ».:•.::ii. ..,' .....;:::::: ' _ [6 .............. _..��if S3Li.�,s�....��L:.��-- .... - - - -- - » .,... r. ...........,,...,. ,...,,... »,:•::;::::::;:i::: ::: ';.. �..».. .- .- ..........: ^.::7:::::�'�`�: : " ^::::::.. ......,, ,,. », _.. %... -.._ .:.:::::: ^Lie ,-, 1._ .•: € Y Iq 505.2 x 5F33 DRAINAGE ALTERNATIVE 1 ..-.._ . SOUTHWEST COPPEIL STORM HATER MANAGEMENT _....._,,'{i MASTER PLAN ! NCH - CITY OF COPPELL INC EA CITY OF COPPELL. TEXAS is i' OWN ASSOCIATES. W. ENNEM • SCENINT5 . SUtY -fM TO 50 s!€=11 axAws DANE ISM141 sorbs F I wo # ° resbuFer mbz rwfs w no r`ww bwFn 'SITE' DETENTION IMPROVE BETHEL STORM DRAINAGE (CULVERT & CHANNEL) PROP SE6 RLTRY-: /CREEKViF-W EXTENSION 21, o- , 6 i V,1 f p,t1il'm 520A Pawl P�Ktlll N 52W x - 519.5 PARK ---- -- -------------- DETENTI '4- x V�13 I X510.7 m pxd, =2 . ... . .... .. DRAINAGE ALTERNATIVE 2 SOUTHWEST COPPELL STORM WATER MANAGEMENT MASTER PLAN NM - CITY OF COPPELL CITY OF COPPELL, TEXAS Mal HXFF ASSOCUiTES, W. ram OMMAMM 9 SCENTM * SURMORS �1OW11li1 DAM RAE MM FU I ft WLP mm"y 1 N-3W 1 "m I LEGEND: C.I.N.V. DFW AIRPORT U.S.P.S. MINYARDS N.C.H. HISTORIC OVERLY m pxd, =2 . ... . .... .. DRAINAGE ALTERNATIVE 2 SOUTHWEST COPPELL STORM WATER MANAGEMENT MASTER PLAN NM - CITY OF COPPELL CITY OF COPPELL, TEXAS Mal HXFF ASSOCUiTES, W. ram OMMAMM 9 SCENTM * SURMORS �1OW11li1 DAM RAE MM FU I ft WLP mm"y 1 N-3W 1 "m I 'SITE' DETENTION IMPROVE BETHEL STORM DRAINAGE (CHANNEL) .. .. .. .. .. kop dISFD nRUBY CREJKVI 1 x 524.4 N -1 - - - - - - - - - - - - x +ARK DETENTION 0 513.2 IN ix DRAINAGE ALTERNATIVE 3 ------------- SOUTHWEST COPPELL STORM WATER MANAGEMENT MASTER PLAN NCH - CITY OF COPPELL CITY OF COPPELL, TEXAS HALFF ASSOMATES, W� mom EPMEMS 9 SCENMTS *SURVEYORS PH • fil. R i OEAION MM UIM KALE WM FU ML nm MW I CAD I MMM 1%-300' 1 Im MM13 LEGEND: C.I.N.V. M DFW AIRPORT M U.S.P.S. T-L M MINYARDS M N.C.H. M HISTORIC OVERLAY FLJLJ 0 G� 0 513.2 IN ix DRAINAGE ALTERNATIVE 3 ------------- SOUTHWEST COPPELL STORM WATER MANAGEMENT MASTER PLAN NCH - CITY OF COPPELL CITY OF COPPELL, TEXAS HALFF ASSOMATES, W� mom EPMEMS 9 SCENMTS *SURVEYORS PH • fil. R i OEAION MM UIM KALE WM FU ML nm MW I CAD I MMM 1%-300' 1 Im MM13 LINEAR DETENTION - RELOCATE BETHEL ROAD SZ5.0 P 5VIU400 .523.21 �o PRO IS S R �r/ URL N -0.1 p PA"M p T52O.4 silo EXTENSION -36000 1 ---- PA--R- Ik ------ DETEN' I .. . . . .. I F ..... ........... 1-4: TX ...... VERTS x5lo.71 I 771 711M LEGEND: C.I.N.V. DFW AIRPORT U.S.P.S. m E MINYARDS N.C.H. HISTORIC OVERLAY -514.6 5",3 r_j C51 ;E ALTERNATIVE 4 IL STORM WATER MAP MASTER PLAN 01,110 NCH - CITY OF COPPELL • CITY OF COPPELL*TEXAS IIAL" ASSOCIATES, WC. 12 EKWEM • • SCENTWIS * SURVEYORS MEN MW MM I MR I WAS I MM MmmmT� FU W ww ca I mumumm 1 Ift3w 1 "m on&= I 1. MIL 520.1 PARK RO RUky /CP.JEEK4" �V EXTENSION DETENTION N x 515.3 FA4 w DRAINAGE ALTERNATIVE 4 SOUTHWEST COPPELL STORM WATER MANAGEMN VERTS MASTER PLm E NCH - CITY OF COPPELL !j CITY OF COPPELL. TEXAS KftFr ASSOCRTES. W. e0NM * SCefrWS a SUM&-jM I mm t RE PAR — I co 1--300' I nlm?mm v Ll LEGEND: C.I.N.V. M DFW AIRPORT I c M M MINYARDS j L M N.C.H. M HISTORIC ET OVERLAY Lfd L. ut "jil f ff—j" LP-1 FA4 w DRAINAGE ALTERNATIVE 4 SOUTHWEST COPPELL STORM WATER MANAGEMN VERTS MASTER PLm E NCH - CITY OF COPPELL !j CITY OF COPPELL. TEXAS KftFr ASSOCRTES. W. e0NM * SCefrWS a SUM&-jM I mm t RE PAR — I co 1--300' I nlm?mm CONVENTIONAL DRAINAGE REGIONAL DETENTION RUB /C Z `iREEKVMW B C N �M f i -R DETENTION . ............ ........... ............ ...... rrr Z XU .2,rl r. " rrrrr I L, �% ........ ...... rrrrr. A u.r - - - - - - - - - - - V, 4 p �,i ttz �,, .............. u y rr.r .. . .. ... ......... ,Z::,; ......... ............... .............. N, ... . .... 1 4 0 SUUTHM51 GUFMLL 5YUKM WAlFK MANAGEMENT MASTER PLAN NCH - CITY OF COPPELL CITY OF COPPELL9 TEXAS MEN HUFF ASSCOATES, Wo ENCIEM • SCENMTS • SURVEYORS 57-7 7,77-71,57-E LEGEND: C.I.N.V. DFW AIRPORT U.S.P.S. MINYARDS I N.C.H. HISTORIC OVERLAY ti . ............ ........... ............ ...... rrr Z XU .2,rl r. " rrrrr I L, �% ........ ...... rrrrr. A u.r - - - - - - - - - - - V, 4 p �,i ttz �,, .............. u y rr.r .. . .. ... ......... ,Z::,; ......... ............... .............. N, ... . .... 1 4 0 SUUTHM51 GUFMLL 5YUKM WAlFK MANAGEMENT MASTER PLAN NCH - CITY OF COPPELL CITY OF COPPELL9 TEXAS MEN HUFF ASSCOATES, Wo ENCIEM • SCENMTS • SURVEYORS ALTERNATE 1 ADDITIONAL 3- 5'x10' LAIS IINU IO'x5' BOX CULVERT ALTERNATE I I A -A EXISTING r anw ADDITIONAL 3- 5'x10' ALTERNATE 1 ALTERNATE 2 ALTERNATE 2 _ ° B YROW EXISTING G ROPOSE® � ADDITIONAL I ADDITIONAL PROPOSED ROW CHANNEL o� ROW REQUIRED PROPOSED REQUIRED ROW _ — CHANNEL _ __ _______ _ FO - — — ,`>-� �. GTE--:- GTE GTE GTE. GTE G e � I ALTERNATE 1" = 100 32 t I I I I O SECTION A —A i i ALTERNA 4-10 a t - ,- g' i r O O O 4- 10'x5' BOX CULVERTS I 00 \5, PROPOSED I' CHANNEL I \� EASTING .> G� '.. EXISTING NATURAL CREEK �. �.1 NATE � L x121 ALTERNATE 1 F' 8 ALTERNATE 1 z_'? EXISTING A0DIi1 ©NAL 3 5D X10 r. ° ADDITIONAL 3 -5'x1 C' I ROW BOX CULVERTS BOX CULVERTS CL lE €G —— -- - - - - - -- c GTE- TE GTE GTE FO . GTEw � � _ �� - - _ GTE— GTE GTE OHE FO FL e — Csi.� a — u ,, •. i .. — _ D _ nuE HF— — 4- 10'x5' BOX CULVERTS QHE _ D' x5' Tn EXISTING EXISTING MfNYAR€iS RAR i -- — — — f a ® , * � BOX CULVERTS OPEN CHANNEL lilt fl ;.- ,� I IE�CiSTiNG ® \e �n PROPOSED f.r. 10'N5' BOX CUL�,!ERT I EXISTING MINYARDS BUILDING 6 � J 10'ss5' BOX (CIULVERT I � EX N® \ \3. CHANNEL J 1i EXISTIN® �D PCI�,\ e - - i� 100 50 0 100 200 ' i -, �•✓ r--� 1" = 100' ALTERNATE SECTION A-A f I � � ®7 ;E Ej4� TT 1� ®/" S' e � EoSTING 1 NATURAL CREEK a�L 1, eel 4-7 mi 0' ~ BOX CULVER TS � J� J W (L — PROPOSED CHANNEL o L Li C.7GJTC�I�L9Li� ALr IqA 1 F I I 1 37' I I 1 I I 90' I _ �I i I I 37' I RIGHT -OF -WAY I I I I I I I I I DRAINAGE EASEMENT I I I I RIGHT -OF -WAY i I i I I I TWO LANE I I I I I I I I I I ONE -WAY I I TWO LANE I TRAFFIC I I ONE -WAY 1 VARIOUS I TRAFFIC VARIOUS UTILITIES I I I I I UTILITIES 1 N w cr I w v w I v w I cr ( Qom? 0?L) 1 Ja ZwN Ja 1 Zui aQ►- I 1 I I az� QZQ I o�� I 00X� 1 croo I um< =:a m< 1 �ov> 1 1 8' 25' 4'161 78' 6' 14' 25' 8' PARKWAY PAVEMENT I I I I 1 I I I I CHANNEL TOP WIDTH I I I I I PAVEMENT PARTWAY I I I I TYPICAL CROSS- SECTION ALONG THE RELOCATED BETHEL ROAD SHOWN IN ALTERNATIVE NO.4 NCH Stream G -1 Master Plan 2r"9 5:31 PM avo 17582 file = 582ak.xis 1998 Pro- development condition model - Existing Condition Peak Flows complete table Proposed Site Detention Propos ed e R e Regional Detention Detention on Airport Property Improved channel on Post Office Property Detention Airport Property Not modeled: Improved channel and/or culvert on Minyards Property Detention on Coppell Industrial N. V. Property Box culvert (2 -1045) from Coppell Industrial N. V. Property to NCH pond Detention on NCH Property (combines south and north tracts) Not modeled: Box culvert (2 -10x5) from NCH pond to Old Towne Creek (Stream G -1) PEAK FLOW IN CUBIC FEET PER SECOND 523.81 PEAK FLOW IN CUBIC FEET PER SECOND Model = NoDetn.out Model = redsgnl.out landuse per zoning map, 95% urbanization Proposed Site Detention Option Model = maxdeLout ROUTED TO Post Office site outtall + Proposed Regional Detention Option AT Airport site outtall I I I HYDROGRAPH AT Airport site outtall AREA -1 0.45 2237 AREA -1 0.45 2237 Page 1 Flood Elevation 523.81 Flood Elevation ROUTED TO Post Office site outtall + ROUTED TO Post Office site outfall ROUTED TO Enla edr reproved Channel to Post Office 523.75 ROUTEI 0.45 1577 + ROUTEI 0.45 9rAn + eO�x site outtall ROUTED TO Post Office site outfall HYDROGRAPH AT Post Office site alone HYDROGRAPH AT Post Office site alone 0.45 1474 -103 -606 + ROUTEI 0.45 373 -1204 -1707 + AREA-2 0.12 815 + AREA -2 0.12 815 HYDROGRAPH AT Post Office site alone HYDROGRAPH AT Post Office site alone + AREA-2 0.12 815 0 0 + AREA -2 0.12 815 COMBINED AT Post Office site outtall 2 COMBINED AT Post Office site outfall 2 COMBINED AT Post Office site outtall 0 0 + COMB -1 0.57 1681 + COMB-11 0.57 2416 + COMB•1 0.57 1579 2 COMBINED AT Post Office site outtall ROUTED TO Pond outfall ROUTED TO Pond outfall 102 837 + COMB -1 0.57 949 -732 -1467 ROUT2a 0.57 1678 ROUT2a 0.57 2396 ROUTED TO Pond outtall ROUT2a ROUTED TO Pond outfall HYDROGRAPH AT Minyards site - west part only HYDROGRAPH AT Minyards site - west part only 0.57 1573 -105 -623 ROUT2a 0.57 931 -747 -1465 AREA3a 0.06 424 AREA3a 0.06 425 HYDROGRAPH AT Minyards site - west part only HYDROGRAPH AT Minyards site - west part only AREA3a 0.06 425 1 0 AREA3a 0.06 425 ROUTED TO West Minyards flows through existing pond ROUT210 ROUTED TO West Minyards flows through existing pond ROUTED THROUGMest Minyards flows through existing 1 0 0.06 22 ROUT210 0.06 22 pond ROUT2b 0,06 ROUTED TO Rest Minyards flows through existing pond Flood Elevation 0 0 4 06 0 0 Flood Elevation Flood Elevation 516.49 516.54 0.05 0 Flood Elevation 2 COMBINED AT existing pond outtall 2 COMBINED AT existing pond outtall 2 COMBINED AT existing pond outfall all 516.54 0.05 0 COMB2a 0.63 1699 COM82a 0.63 2417 COM82a 0.63 1594 2 COMBINED AT existin g pond outfall ROUTED TO Minyards site outfall - Freeport Prkwy ROUTED TO Minyards site outtall - Freeport Prkwy ROUTED TO 105 -823 COMB2a 0.63 952 -747 -1465 ROUT2c 0.63 1679 ROUT2c 0.63 2348 Minyards site outfall - Freeport Prkwy ROUT2c ROUTED TO Minyards site outfall . Freeport Prkwy 0.63 1546 -133 -802 ROUT2c 0.63 888 HYDROGRAPH AT Minyards site - east part only AREA3b HYDROGRAPH AT Minyards site - east part only HYDROGRAPH AT Minyards site - east part only •791 -1460 0.07 497 AREA3b 0.07 503 AREA3b HYDROGRAPH AT site -east part only 0.07 503 6 0 AREA 3b ARFA3b 0.07 503 6 0 ROUTED TO upstream face of Bethel rd culverts + ROUTED TO upstream face of Bethel rd. culverts awl MM ROUTED TO upstream face of Bethel rd. culverts ROUTE3 0.71 1722 + ROUTE3 0.71 2443 + ROUTE3 0.71 1576 ROUTED TO upstream face of Bethel rd. culverts HYDROGRAPH AT Various sites south of Bethel Rd. HYDROGRAPH AT Various sites south of Bethel Rd. -146 -867 + ROUTE3 0.71 1256 -466 -1187 + AREAS 0.1 678 + AREA -4 0.1 681 HYDROGRAPH AT Various sites south of Bethel Rd. HYDROGRAPH AT Various sites south of Bethel Rd. + AREA-4 0.1 681 3 0 + AREA -4 0.1 681 3 0 HYDROGRAPH AT NCH small south site atone HYDROGRAPH AT NCH small south site alone + AREA-5 0.02 146 + AREAS 0.02 162 HYDROGRAPH AT NCH small south site alone 2 COMBINED AT downstream face of Bethel rd. culverts 2 COMBINED AT downstream face of Bethel rd. culverts * AREA-5 0.02 162 16 0 + COMB-4 0.83 2277 + COMB 4 0.83 2705 2 COMBINED AT downstream face of Bethel rd. culverts ROUTED TO Coppell Rd. ROUTED TO Coppell Rd. + COMB -4 0.83 1999 -278 -706 R UTE4 0.83 2246 + ROUTE4 0.83 ROUTED TO Coppell Rd. 2658 + ROUTE4 0.8 2009 -237 .649 HYDROGRAPH AT Dallas Brewery site + HYDROGRAPH AT- Dallas Brewery site HYDROGRAPH AT Dallas Brewery site y� - AREA-6 0.05 304 + AREA-6 0.05 .05 304 + AREA 6 HYDROGRAPH AT Dallas Brewery site ROUTED TO NCH outtall A105 304 0 0 + AREA -6- 0.05 0 0 • ROUTES 0.05 ROUTED TO NCH outfall 185 + ROUTES 0.05 ROUTED TO NCH outfall l 253 + ROUTED TO NCH outfall ROUTES 005 253 S1 + ROUTES 0.05 253 !ie 0 Page 1 Page 2 complete table r HYDROGRAPH AT Co ppell Industrial N.V. site AREA-7 0.15 1049 �i Flood Elevation 517,34 ROUTED TO + NCH outfall ROUTE6 0.15 724 ROUTED TO NCH outfall + ROUTED TO NCH outfall through proposed 9 P posed 2 -10x5 boxes ROUTE6 0.15 970 + ROUTE6 0.15 762 38 ROUTED TO NCH outfall 2 COMBINED AT NCH outfoll 2 COMBINED AT NCH ouNall -208 + ROUTE6 0.15 970 2qg 0 + COMBS 0.2 758 + COMBS 0.2 1019 2 COMBINED AT NCH outfall + COMBS COMBINED AT 11 Duffs ;• K., k. ffi 02 811 HYDROGRAPH HYD AT NCH large north site 53 + 208 COMBS 02 1019 261 0 AREA -a + 0.15 1025 193 0a HYDROGRAPH AT NCH small south site alone AREAS 0.02 162 2 COMBINED AT proposed NCH detention pond COMB-4 0.18 1188 R Ua mttr `�pottd z � � Flood Elevation 510.32 MUM- t,OM INEDAT:' n ROUTED TO Coppell .: A 5 ..: it y, i ,v b N [ ., 05 ", + .* jg g _ S : + Rd. ROUTED TO Coppell Rd. ROUTED TO Coppell Rd. H_ -�a; ROUTE7 0.36 1102 + ROUTE7 0.36 1668 + ROUTE7 0.38 1605 ROUTED TO Coppell Rd. HYDROGRAPH AT Historical district upstream of Coppell rd. HYDROGRAPH AT Historical district upstream of Coppell rd. HYDROGRAPH 503 -63 + ROUTE7 0,36 1668 566 p + AREA -9 0.02 144 + AREA -9 0.02 145 AT Historical district upstream of Coppell rd. + AREA-9 HYDROGRAPH AT Historical district upstream of Coppell rd. 1N `R 0.02 145 1 0 + AREA-9 0.02 145 1 _ BST _ ROUTED TO + Grapevine creek confluence ROUTED TO Grapevine creek confluence ROUTED TO Grapevine creek 7 1 2 3017 + 7 1.2 3960 confluence + 7 1.2 3211 ROUTED TO Grapevine creek confluence HYDROGRAPH AT Area downstream of Coppell Rd. HYDROGRAPH AT Area downstream of Coppell Rd. 194 -749 + 7 1.2 3021 4 939 + TG -1S 0.21 959 + HYDROGRAPH AT Area downstream of Coppell Rd. TG -1S 0.21 959 + TG -1S 0.21 959 HYDROGRAPH AT Area downstream of Coppell Rd. COMBINED AT + Grapevine creek confluence 2 COMBINED AT Grapevine week confluence 2 COMBINED AT Grapevine creek confluence 0 0 + TG -1S 0.21 959 0 0 6 1'41 3626 + 6 1.41 4663 + 6 1.41 3856 2 COMBINED AT Grapevine creek confluence 230 -807 + 6 1.41 3764 138 -899 Page 2 i2 c 0 m w 51 500 0 ---- —vv 0vvv uvuu 10000 12000 Main Channel Distance (ft) Legend WS Fully Dev. ■ Ground 51 Z c 0 a� ui R ouvv UUM 10000 12000 Main Channel Distance (ft) Legend _ .......... WS Site Det. ■ Ground Revised Existing Conditions Model Alternative 3 2/4/99 520 Legend WS Site Det. ■ Ground 518 516 514 i l _- ... . c 512 w 510 508 506 5041. 0 500 1000 1500 2000 2500 Main Channel Distance (ft) 611 F_ c 0 a� w - - -- ���� vvvv uvuu 10000 12000 Main Channel Distance (ft) Legend ..... __ ..... ...._...__ ........... _ - -___ WS Reg. Det. Ground