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Home My WebLink AboutKlotz Draft Report for Fairmont Park East and Brookglen 072809July 22, 2009 Mr. Ron Bottoms City Manager City of La Porte 604 W. Fairmont Parkway LaPorte, Texas 77571 RE: City of La Porte, Texas Diversion of HCFCD Unit B 112-02-00 to Unit B 109-03-00 Klotz Associates Project No. 0 127. 011.000 Dear Mr. Bottoms: Klotz Associates was authorized in July 2009, by the City of La Porte, to perform a hydrologic and hydraulic analysis to evaluate Harris County Flood Control District (HCFCD) Unit B 112-02-00 and determine if redirecting the channel to drain east to Unit B109-03-00 provides a benefit to the Brookglen Subdivision. This report documents downstream benefits and impacts for Unit B 112-00-00 and Unit B 109-00-00 and costs associated with these improvements. This is a preliminary assessment intended to support City staff in identifying possible projects to relieve flooding in Brookglen Subdivision. Klotz Associates is pleased to submit this draft letter report for the City in coordinating with the Harris County and the HCFCD. Understanding A review of the local drainage for the Brookglen subdivision area indicates that the subdivision is drained by storm sewers. The storm sewers have about a 3 year capacity before ponding begins to occur within the subdivision. A review of the subdivision area indicates that there is not any apparent sheet flow path to provide a relief of the excess flows when the storm sewers are at capacity. The LIDAR map also substantiates this issue. During heavy rainfall events the water will pond up within the streets and subdivision areas and causes local flooding of the structures. The Brookglen area has experienced flooding of many of the residential structures. A review of the drainage ditches draining the area including B 112-00-00, B 112-02-00, B109-03-00 and B109-00-00 all indicate that the adjacent channels have fairly good capacity in the channels up to the 100 year event. The B 112-00-00 channel in the area of the Brookglen subdivision is concrete lined and appears to have about a 100 year capacity and is draining part of the City of La Porte and part of the City of Deer Park. This B112-00-00 channel does not have any large detention Mr. Ron Bottoms July 22, 2009 Page 2 of 12 facility located on it or upstream of it. During the recent flood event John Randolph with HCFCD noted that water from B 112-00-00 channel had overtopped the chanxiel and went over Spencer Road. The B 112-02-00 tributary is an earthen channel, does have a large HCFCD detention facility located upstream of Spencer Road and would be easier to improve and enlarge than removing the concrete within the B 112-00-00 channel. The slab elevations of the residential structures indicate that the slabs that were surveyed are all above the 100 year event flood levels from the receiving channel from the downstream areas of channel B112-00-00. However the tributary channel B112-02-00 does not have 100 year capacity but has high levels within the channel when B112-00-00 channel is flowing full. Field observations by City staff and from HCFCD indicate that the water from B112-02-00 cannot easily enter the main channel of B112-00-00 and thus creates a backwater effect within the Brookglen subdivision. Reducing the backwater effect of the B 112-02-00 channel on the Brookglen subdivision is the focus of this analysis. The issue that is being addressed in this report is if the B 112-02-00 channel were reconnected back to the B109-03-00 and B109-00-00 channel could the backwater effect in the Brookglen subdivision area be reduced enough to help the drainage with the subdivision. Also included with this analysis would be channel improvements and appropriate mitigation within the B 109-00-00 watershed to mitigate the diversion of the Brookglen subdivision area to B 109-00-00 channel. Purpose and Scope The purpose of this letter report is to identify benefits, downstream impacts and document changes in computed water surface elevations relating to possible diversion of Unit B 112-02-00 from Unit B 112-00-00 to Unit B 109-03-00. The following is the Scope of Services association with the project: 1. Prepare a broad based hydrologic analysis for the simulation of redirecting Tributary 1.78 to Willow Springs Bayou, or Unit B 112-02-00, to drain from west to east and disconnected Unit B 112-02-00 from Willow Springs Bayou, or Unit B 112-00-00. 2. Prepare a broad based hydraulic analysis for the simulation of redirecting the Tributary 1.78 to Willow Springs Bayou, or Unit B 112-02-00, to drain from west to east and disconnected Unit B 112-02-00 from Willow Springs Bayou, or Unit B 112-00-00. Mr. Ron Bottoms July 22, 2009 Page 3 of 12 3. Document estimated impacts to HCFCD Units; B112-00-00, B112-02-00, B109- 03-00 and B 109-00-00, due to diverting flow in B 112-02-00 from Willow Springs Bayou (B 112-00-00) to Spring Gully (B 109-03-00). 4. This analysis is intended to document flow changes, pre -project and post -project computed water surface elevations in B112-00-00, B112-02-00, B109-03-00 and B109-00-00 due to the diversion for discussion purposes for two (2) options. for mitigation. 5. Prepare letter report. 6. Submit letter report for the analysis to La Porte, Harris County Flood Control District and Harris County reflecting the changes in flows and changes in water surface elevations to the 10, 50 and 100 year event storms. 7. This assumes one meeting will be needed to present and discuss the findings with HCFCD or Harris County. Note: The terms "broad based... analysis" are intended to describe the purpose, or convey the intent, behind the methods used in this analysis. Boundary conditions and drainage parameters were simplified the methodology for and to calculate estimated results connected with specific channel modifications in combination with detention, and for the purpose of exploring potential project alternatives and their related benefits and costs associated with said results and to determine the feasibility of implementing improvements described in this report.. This is not a detailed hydrologic and hydraulic study. This report is not intended to provide recommendations for the construction of detention sites or channel improvements, of any manner, without property detailed study and approval from Regulatory agencies that exercise jurisdiction over MS4s, or ditches, storm sewers, main stem streams or any system that functions to collect and/or convey storm water runoff, be it, owned or operated by a public agency; or Special Flood Hazard Areas (SFHA) defined by FEMA in the NFIP. Studied Area The study area is located in the City of La Porte (City), located in southeast Harris County, Texas, and is located in the Armand Bayou Watershed. The primary area of interest includes the subwatersheds of B 11202A, B 109A, B 112A and B112B. The studied channels include Willow Springs Bayou (HCFCD Unit B 112-00-00), Spring Gully (HCFCD Unit B 109-00-00), and Tributary to Willow Springs Bayou (HCFCD Unit B 112-02-00). The focus of this study is redirecting flows from B 112-02-00 from B 112- 00-00 to B109-03-00, contributing approximately 166-acres of residential development in subwatershed B 11202A. Mr. Ron Bottoms July 22, 2009 Page 4 of 12 Study Background Interconnect B109-03-00: Original purpose of the interconnect B 109-03 -00 was to divert flood waters along B 112- 02-00 to the improved downstream channel B109-00-00 and reduce flooding in Brookglen Subdivision and Spencer Highway Estates Subdivision during a 100-year storm event. According to a report entitled, Hydrologic and Hydraulic Study for Interconnect of HCFC Unit B112-02-00 to Unit B109-00-00 and HCFC Regional Detention Site Unit B512-01-00, by WSA in April 1997; HCFCD constructed an interconnect, now called B109-03-00, between Tributary 1.78 to Willow Springs Bayou (B 112-02-00) and Spring Gully (upper B 109-00-00) as an interim solution to "reduce widespread flooding" along B 112-00-00 and B 112-02-00. Prior to construction of interconnect B109-03-00, B112-02-00 drained all of subwatershed B11202A, an area approximately 1,612 acres located in the City of Deer Park, eastern limits and north of City of La Porte. The limits of B109-03-00 are between B112-02-00 and approximately 700 feet to the south of B112-02-00 and just south of Carlow Street to the east approximately 900 feet to B109-00-00. Construction of the interconnect B109-03-00 was completed in November 1993 in accordance to plans prepared by J.A. Costanza & Associated Engineering, Inc., dated February 1992, see "Data Collected and Prior Reports". The disconnect of B 112-02-00 at Canada Street was performed to divert all flows coming from B512 01 00 into B 109-00-00 under the ultimate development plan in order to have no impacts to Armand Bwith the interconnect in place and 1997 develo meat. HCFCD Detention Basin B512-01-00: originally, an interim plan recommended by WSA in 1997, proposed detention basin B512-01-00 serve to provide: (1) Downstream flood protection along B112-02-00 and B 112-00-00, "primarily" in Brookglen Subdivision and Spencer Highway Estates Subdivision, (2) Mitigate impacts along Armand Bayou (B 100-00-00) from constructing the interconnect B109-03-00; (3) Provide detention required from constructing East Boulevard Roadway. According to WSA's 1997 report, the interim plan provided flood protection along B 112-02-00 for a 10- to 25-year storm event level between Spencer Highway and the interconnect. The interconnect split the 100-year flows from B512-01- 00 on the order of 75% (about 760 cfs) of the flow was added to B109-00-00, (and 75% removed from discharging into B 112-00-00) and 25% (about 254 cfs) continued downstream in B112-02-00. Interim mitigation plan provided 351 ac-ft that outfalls using 2-7' x 6' RCB's under an 80-foot spillway discharging 1015 cfs into B112-02-00 at a depth of 9.5-feet. Mr. Ron Bottoms July 22, 2009 Page 5 of 12 The ultimate plan provides for: (1) Provide detention storage for ultimate development of 1311202A, (2) Diverting all flow from B512-01-00 to B109-00-00, (3) Channel improvements between Carlow Street and B512-01-00 to convey full discharge from the outfall structure for the 100-year event with full development in B 11202A. Ultimate mitigation plan provided 720 ac-ft that outfalls using 2-7' x 5' KCB's under an 80-foot spillway discharging 1200 cfs into B112-02-00 at a depth of 14-feet. Disconnecting B 112-02-00 at Canada Street diverted 100% of flow from upstream of Canada Street to B 109-00-00; however, (1) Does not divert 100% of fully developed flow in B 11202A namely ultimate development flows in the reach between B 112-00-00 and Canada Street for the 100-year event. Data Collected and Prior Reports Prior drainage reports have also been collected and reviewed. The following reports and studies were reviewed: • Ci -Wide Drainage Stud or the Ci o La Porte in January 2009 by Klotz Associates, Inc. ■ Iydrologic and Hydraulic Study for Interconnect afHCFC Unit B112-02-00 to Unit B109-00-00 and HCFC Re ional Detention Site Unit B512-01-00 in April 1997 by Wilbur Smith Associates, Consulting Engineers and Planners ("WSA") 1. Study of Interconnecting Unit BI12-02-00 with Unit B109-00-00 in the Armand Bayou Watershed, prepared for HCFCD, by Espey, Huston & Associates, Inc. ("Espy Huston"), July 1988 and revised March 1989. This study is an update to report entitled, Preliminary EngfneeringReport, B109-00-00 Analysis ofDivertin_g Water From B-112-02-00 into B-109- 00-00, for HCFCD by Espy Huston, September 1982. Note: This study determines: (1) Impacts of interconnecting Tributary 1.78 to Willow Springs Bayou (B 112-02-00) to Spring Gully (B 109-00- 00) on channels B100-00-00 (Armand Bayou), B112-00-00 (Willow Springs Bayou) and Spring Gully (B 109-00-00); (2) A conceptual plan for detention to mitigate impacts from the interconnect; (3) A conceptual plan for channel improvements and detention for ultimate development in Subwatersheds B 11202A and B 109A. 2. Construction Drawing, Harris County Flood Control Ditch No. B109-00- 00, prepared for HCFCD, by Espy Huston, April 1985, (Record drawings issued on August 30, 1991). Mr. Ron Bottoms July 22, 2009 Page 6of12 Note: Limits were just upstream of Carlow Street to Armand Bayou, approximately 1.9 miles and did not include the interconnect of B 112-02- 00 to B109-00-00. 3. Construction Drawings, Spring Gull — HCFC Unit 109-00-00 prepared for HCFCD by J.A. Costanza & Associates Engineering, Inc. ("Costanza"), February 1992, (Record Drawings issued on November 19, 1991). Note: These are the record drawings for constructing the interconnect of Tributary 1.78 to Willow Springs Bayou (B 112-00-00) to Spring Gully (B 109-00-00). 4. Construction Drawings, Preliminary Plan for HCFC Regional Detention Basin Site No. B512-01-00-21-001.0, prepared for HCFCD by Sander Engineering Corporation ("SEC"], October 1994. Note: Construction drawings for excavation in HCFCD BS 12-01-00 providing a design storage capacity of 237 ac-ft at an elevation of 23 ft (1973 NGVD) on an 80 acre tract of land north of Spencer Highway. 5. Flood Insurance Study crud Flood Insurance Rate Map (FIR11g]. Harris County, Texas and Incorporated Areas, 11Iap Number 48201 C0940 and 48201C1080, by FEMA for the NFIP, November 6, 1996 Map Revision. Up-to-date hydrologic models (HEC-HMS) and hydraulic models (HEC-RAS) based upon information developed as a consequence of the Tropical Storm Allison Recovery Program (TSARP) are readily available from HCFCD and have been incorporated into the information for this project. LiDAR (light detection and ranging technology) elevation data are also readily available from HCFCD. The HCFCD provided Klotz Associates with slab elevations for some of Brookglen Subdivision. In support of the City -Wide Drainage Study (CWDS), the City provided Klotz Associates with their GIS data related to drainage issues, including repetitive loss information, storm sewer layout, culverts data, information on severally flood -damaged homes, inlets and manhole locations, and floodplains maps. Floodplains delineated and recognized by 'the Federal Emergency Management Agency (FEMA) floodplains are shown in Exhibit 1. Repetitive loss data provided by the City is shown in Exhibit 1 &3. options Modeled Each of the options were modeled for preliminary results to determine changes and water surface and flows occur and the magnitude of those changes. A detailed analysis of the Mr. Ron Bottoms July 22, 2009 Page l❑f12 watershed should be conducted to determine actual changes. A summary of the changes is located at the end of this section. Option 1 The first option includes all the following items and shown in Exhibit 4: 1) Interconnect Spring Gully (HCFCD Unit B 109-03-00) and Tributary 1.78 to Willow Springs Bayou (HCFCD Unit B 112-02-00). This includes connecting the east end of B112-02-00 to B109-03-00 and local channel improvements. 2) Disconnect Willow Springs Bayou (HCFCD Unit B 112-00-00) and Tributary 1.78 to Willow Springs Bayou (HCFCD Unit B 112-02-00). This means damming off the west end, or disconnecting, B112-02-00 from B112-00-00 (Willow Springs Bayou). 3) Add a low flow drain pipe at the disconnect to drain B 112-02-00. Install a low flow pipe at the proposed disconnect to drain B 112-02-00 into B 112-00-00 during periods of no rain or when B109-03-00 empties. No channel improvements are proposed for B112-02-00 nor is the existing flow line modified. 4) Add a bridge or Five (5) 11'x 10' reinforced concrete boxes (KCB's) along with local channel improvements at B112-02-00 and Canada Street. 5) Spring Gully (B109-03-00 & B109-00-00) Channel Improvements between the proposed interconnect of B 112-02-00 and B 109-03-00 to approximately 4,800- feet south to Future HCFCD Detention Basin B509-03-00 51.0 ac-ft of channel excavation). Typical section is a trapezoidal shape about 14-feet deep with bottom widths that vary from 20-feet to 35-feet and 4:1 side slopes. 5) Interim detention in Future HCFCD Detention Basin Unit B509-03-00 of approximately 92 ac-ft with a stabilized earthen inflow weir and outfall pipe. Mitigation of the increases in flow from B 112-02-00 and additional conveyance in B109-00-00 will be handled by constructing a portion of detention basin B509- 03-00 with temporary inflow and outfall structure. Option 2 The second option includes all the following and shown in Exhibit 5: 1) Propose 56.4 ac-ft for detention along B112-00-00, B 112-02-00 and B 109-03-00 to reduce the amount of detention required in HCFCD basin B509-03-00 and minimize needed channel improvements in B 109-00-00 to convey flow. a. Location D1 —14.8 ac-ft of storage is available for detention along B112- 02-00 from 1.9 acre buyout location along Gladwyne Court. This requires purchase of two (2) single family houses, demolition of the structures and excavation on Gladwyne Court. Mr. Ron Bottoms July 22, 2009 Page 8 of 12 b. Location D2 — 8.0 ac-ft of storage is available for detention along B112- 00-00 from 1.14 acre City owned property on Bandridge Road. This location is currently undeveloped. c. Location D3 — 26.0 ac-ft of storage is available for detention along B 112- 00-00 from 2.5 acres the City owns between Somerton Drive and B112- 00-00. This is an undeveloped open area in the park area that is bound by the public pool to the north, utility corridor to the south, B 112-00-00 to the West and Somerton Drive along the east. d. Location D4 — 8.0 ac-ft of storage is available for detention at the confluence of B 109-03-00 and B 109-00-00 in an undeveloped area that is 0.8-acre in size. 2) Interconnect Spring Gully (HCFCD Unit B109-03-00) and Tributary 1.78 to Willow Springs Bayou (HCFCD Unit B 112-02-00). This includes connecting the east end of B 112-02-00 to B 109-03-00 and local channel improvements. 3) Disconnect Willow Springs Bayou (HCFCD Unit B 112-00-00) and Tributary 1.78 to Willow Springs Bayou (HCFCD Unit B112-02-00). This means damming off the west end, or disconnecting, B112-02-00 from B112-00-00 (Willow Springs Bayou). 4) Add a low flow drain pipe at the disconnect to drain B 112-02-00. Install a low flow pipe at the proposed disconnect to drain B 112-02-00 into B112-00-00 during periods of no rain or when B109-03-00 empties. No channel improvements are proposed for B 112-02-00 nor is the existing flow line modified. 5) Add Five (5) 1 Vx 10' reinforced concrete boxes (KCB's) and local channel improvements at B 112-02-00 and Canada Street. 6) Spring Gully (B109-03-00 & B109-00-00) Channel Improvements between the proposed interconnect ofB112-02-00 and B109-03-00 to approximately 4,800- feet south to Future HCFCD Detention Basin B509-03-00 (36.0 ac-ft of channel excavation). Typical section is a trapezoidal shape about 14-feet deep with a bottom width that ranges between 5-feet to 30-feet and 4:1 side slopes. 7) Interim detention in Future HCFCD Detention Basin Unit B509-03-00 of approximately 35.0 ac-ft with a stabilized earthen inflow weir and outfall pipe. Mitigation of the increases in flow from B 112-02-00 and additional conveyance in B 109-00-00 will be handled by constructing a portion of detention basin B509- 03-00 with temporary inflow and outfall structure. Mr. Ron Bottoms July 22, 2009 Page 9 of 12 Option 2 can be phased in over time by breaking out detention locations D1 and D2 on B 112-00-00 and D3 on B 112-02-00, see Exhibit 6 for detail. Option 2 Phase 1, is an interim condition by constructing 49.0 ac-ft of detention in both B112-00-00 and B112- 02-00 first. The remaining design elements can be constructed in the future. Option 2, Phase 1 includes: 1) Propose 49.0 ac-ft for detention along B 112-00-00, B 112-02-00 and B 109-03-00 to reduce the amount of detention required in HCFCD basin B509-03-00 and minimize needed channel improvements in B 109-00-00 to convey flow. a. Location D1 --14.8 ac-ft of storage is available for detention along B112- 02-00 from 1.9 acre buyout location along Gladwyne Court. This requires purchase of two (2) single family houses, demolition of the structures and excavation on Gladwyne Court. b. Location D2 — 8.0 ac-ft of storage is available for detention along B 112- 00-00 from 1.14 acre City owned property on Bandridge Road. This location is currently undeveloped. c. Location D3 — 26.0 ac-ft of storage is available for detention along B 112- 00-00 from 2.5 acres the City owns between Somerton Drive and B112- 00-00. This is an undeveloped open area in the park area that is bound by the public pool to the north, utility corridor to the south, B112-00-00 to the West and Somerton Drive along the east. Model Results Option 1 resulted in a maximum water surface reduction in B 112-00-00 of -0.60 ft with an average of -0.23 ft, and maximum flow reduction of -301 cfs. Maximum water surface reduction in B109-00-00 is -0.36 ft and occurs in B109-03-00. Average water surface reductions along B 112-02-00 are -0.89 ft between B 112-00-00 and Canada Street. Option 2 provides an average water surface reduction in B 112-00-00 of -0.44 ft and average flow reduction of -269 cfs. Average water surface reduction in B 109-00-00 is estimated at -0.13 ft and average flow increases around 65 cfs. Average water surface reductions in B 112-02-00 are -1.09 ft between B 112-00-00 and Canada Street with associated reductions in flow of -182 efs. Option 2 Phase 1 provides an average water surface reduction in B 112-00-00 of -0.19 ft, and average flow reduction of 94 efs. Average water surface reductions in B112-02-00 are -0.46 ft between B 112-00-00 and Canada Street with associated flow reductions of 242 cfs. The water surfaces and flows in B109-00-00 do not change because no work is Mr. Ron Bottoms July 22, 2009 Page 10 of 12 performed on the reach between detention basin B512-01-00 and Armand Bayou (B100- 00-00). Table I Cnmmav%T ni Watpr swnd Flaw rhanuec Channel Average Changes in WS & Q Reach Option 1 Option 2 Phase 1 Phase 2 WS Change Q Change WS Change Q Change WS Change Q Change (ft) (cfs) (ft cfs (ft) (cfs) B112-00-00 -0.23 -140.58 -0.19 -94.37 -0.44 -269 B 112-02-00 -0.89 0.00 -0.32 -242.20 -1.09 -182 B 109-00-00 0.03 162.62 0.00 0.00 -0.13 65 Construction Estimates Estimates were generated for each of the options and are included in the attachments. Option IA is Option 1 estimated with a bridge structure at Canada Street and also includes extensive channel improvements along B 112-02-00 to reverse the grade to flow west to east. This is the most expensive of the options. Option 1 B is Option 1 estimated with reinforced concrete boxes at Canada Street and does not include any channel work except at the dammed off portion at B112-00-00 and the tie-in to B109-03-00. This is the least expensive option. Option 2 turned out to be between Option 1 A and B in construction costs. Option 2 includes detention located along B 112-00-00 and B 112-02-00, thereby; reducing the amount of potential detention required in future B509-03-00. Mr. Ron Bottoms July 22, 2009 Page 11 of 12 Table 2 Cnmmf ry of C nctc Option lA $ 3,970,350 Option 113 $ 2,863,870 Option 2 $ 3,542,610 Break Out Option 2 in Phases: Option 2, Phase 1 $ 1,116,200 Option 2, Phase 2 $ 2,426,410 Conclusion Option 1 produced reductions along B 112-00-00 and B 112-02-00 with increases along B 109-00-00. The increases along B 109-00-00 are associated with optimizing the amount of detention required, the shape of the detention basin and how it functions, and finally the location of detention within the reach to properly attenuate the increases in flow. Therefore, thorough analysis and design of HCFCD regional detention basin B509-03-00 are key to optimizing its performance which is beyond the scope of services for this work. This is the least expensive option but, all components will need to be constructed at the same time. Option 2 generated results with higher magnitudes than Option 1. This is expected because detention is provided upstream before flows are diverted to receiving streams B112-00-00 and B109-00-00. There is still an increase in flow of 65 cfs generated in B109-00-00 associated with a net decrease in water surface of -0.13. Breaking out Option 2 into phases produces benefits for the interim with reductions in computed water surface elevations and flows associated with the 100-year storm event for both B112-00- 00 and Bl12-02-00. Whether Option 2 is constructed in phases or at one time, costs associated with this option fall between Option lA and 1B. On site detention located within City limits adjacent to B 112-00-00 and B 112-02-00 is something the City of La Porte can act on in the interim. Additionally, a detailed hydrologic and hydraulic analysis of the Armand Bayou (B 100- 00-00) watershed should be performed to properly model the impacts of changes associated with these options. We recommend Option 2 as a possible project for the City. The overall benefit is greater in reductions to both water surface and flow with the flexibility to perform Mr. Ron Bottoms July 22, 2009 Page 12 of 12 implementation in phases over a period of time. This is not the least expensive solution but, with on site detention located with City Limits there may be flexibility for the City to find opportunities to reduce these costs. We are available to discuss this report with you at your convenience. Summary data has been included in the exhibits and appendices however much more data is available. We look forward to moving into the next phase of work. Sincerely, Gary L. 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M � �- M� a rn. M �'! ' a N N M ¢ 9�9 ao 9o.9444. N N NNN N N N N N N N N N N I r-n n•n nnn r-nnr-nnn i '.c+ v v o a a rn a a v a p v o a v v p S o o o v y v.o p o.o ala'v p'p p,o o 0 u m I FC: P7 i b� v pI•� �r-nn N N N r-NN N oa M fM'fN Ln � �L �O n' ; m v� T N . I, I [�V nt�- n:�ea om rn'rn C ry ryn.co �4 4'ac a 40 9 c'c ov oo'vp;ol i ,v vpo avp M oc,ocao N N N n ov'irnlN N— C,6 ' N 11 -N N N!N N N, d h1 N N N N N N [ i CV C4 fJ [V N ��I7',7 N C. N N N N lV N N � o w Q m o:v a,; C, of v y N M .G v0 oa .-• C C pro OIC c' e O G P O CMG 4 . N N .p N N N N 'a. CI N N N N'N N p N N N N N N;N,N N N NI.N '• N N r "�' a p i'' C] �'rl M N1 Cl �'rl ' M t�1 i M !I 1 C [�1 • [�•I f'1 M �"t � too I �^ - y �' N �' � h • r 07 C, T �'i ? I� ' ool000 z oa • ca' �' l a :L U P Table 4 Potential Detention Ponds ^11,,uu� 4 _� '''�R�f ��' ':jr; .:•yx �-;�Z::s':.: ...,ti •, xx.. .,41. "[j.�;"1��. �" .;:1..;1;' Ii1i1; i'"�''�^i. �.,��; F''';��.Y: l..n., �I,k':�'il.;:..,+ .... .1•: M1'; +.. '�''Y�:iA��•', :.y ;i+1:':gi�:: �.'7il:: �` ,a,• i,,.::y1:�,,.Y,.w1,, ;''>:iix" �IS.'.�'• �iY':3.� '.,.f �:i�,d:C2id]a"v: •.,w:`:7dr1'i� ' V laati l. !... 4`,i'., :�.... a. . • �w 1.'.:•.C. -!F'.+!^ �':�1:� {•.1.... • ..vie ...�. C.�?� r®® ' Total 56.4 Notes: 1. See Exhibit 5 for Site Location 2. Potential Volume does not include freeboard 3. Potential Volume does not include maintenance berm between pond and channel. Table 5 Required Detention ' � �'11�1:rlk�:ir.l..kr�u• "•r'1kc�:t...:�.::�C�' �y- yy i�u��..::.yy�'"r�aif '�.r:;:�'. EF yy��sw.��•.•�� _� ,.-.r.—._._.,..,. _.,..-..—.r.......... aK C I 1202A® '~ .F ■. � — � . �::• r-s r".��': ear:' a'�Y".. •.®.i;.�:x;;:...® .. -T;�-3L(5 Note: These estimates are to aid City of La Porte staff for planning purposes only. Unit prices and quantities are approximate and subject to change. Eng!nee hng design methods were not performed to develop estimates, presented herein, and shall not be used for bidding purposes. Actual construction estimates shall be determined based on performing professional engineering design services. Igotr Associates Project No- 0127.011-000 B112-02-00 drainage Study City of La Porte .]iiM 20M Table 1 Ration 1A (Bridge) Option 'IA - Grade B112-02-00 FL to Drain East & Bridge at Canada St. Item No. Item Description Unit Estimated Quantity Unit Price Total Cost 1 Mobilize & Prepare Right -of -Way (5% of Total) LS 1 $ 143,755 $ 143,756 Rework Channel Flow Line (2,600 LF) 2 Remove & Dispose of Existing Concrete Slope Pavement CY 1,763 $ 6.70 $ 11,812 3 Excavation (Channel) CY 2,900 $ 4.80 $ 13,920 4 Embankment CY 2,100 $ 7.50 $ 15,750 5 15" Reinforced Concrete Riprap, 2 Slopes at 2: 1, Av. Depth 8.5, (include Subgrade Work) CY 821 $ 270 $ 221,667 6 8" Concrete Bottom Section (30' wide) CY 1,037 $ 300 $ 311,111 Subtotal Rework Channel Flow line (2,600 LF): $ 574,260 B109-03-00 & B109-00-00 Channel Improvements (4,800 LF) 7 Remove & Dispose of Existing Concrete Slope Pavement CY 269 $ 6.70 $ 1,804 8 Excavation (Channel) CY 82,789 $ 4.80 $ 397,387 g 5" Reinforced Concrete Riprap, 2 Slopes at 2: 1, Av. Depth 8, (include Subgrade Work) CY 994 $ 270 $ 268,328 10 Concrete Low Flow Section (12' wide) CY 1,264 $ 300 $ 379,259 Subtotal B109-03-0 & B109-00-00 Channel Improvements (4,800 LF): $ 1,046,778 Canada St. Bridge over 13112-02-00 (Pier & Beam) 11 Bridge ($50 I SF of Deck Surface) SF 7,020 $ 50 $ 351,000 12 Remove & Dispose of Existing Concrete Slope Pavement CY 393 $ 6.70 $ 2,630 13 Excavation (Channel) CY 8,711 $ 4.80 $ 41,813 14 Approaches & TCP (Assume 26% of Bridge) LS 1 $ 87,750 $ 87,750 Subtotal Canada St. Bridge over B112-02-00 (Pier & Beam): $ 483,194 Klotz Associates Project No. 0127.011.000 B112-02-00 Drainage Study July 2009 1 of 2 City of La Porte Table 1 Option 1 A (Bridge) Option I - Grade 13112-02-00 FL to Drain East & Bridge at Canada St. Item No. Item Description I Unit I Estimated Quantity Unit Price Total Cost B112-02-00 Disconnect & Dam at 13112-00-00 15 Remove & Dispose of Existing Concrete Slope Pavement CY 128 $ 6.70 $ 855 16 Excavation (Channel) CY 366 $ 4.80 $ 1,756 17 Embankment CY 1,170 $ 7.50 $ 8,775 18 15" Reinforced Concrete Riprap, 2 Slopes at 2:1, Av. Depth 8.6, (Include Subgrade Work) CY 21 $ 270 $ 5,610 19 Concrete Low Flow Section (1V wide) CY 20 $ 300 $ 5,926 Subtotal B112-02-00 Disconnect & Dam at B112-00-00: $ 22,923 B509-03-00 Detention Basin (166 ac Area at 0.65 ac-ftlac = 91.3 ac-it Required) 20 Detention Excavation CY 147,300 $ 4.00 $ 589,200 21 Interceptor Structures EA 8 $ 2,500 $ 20,660 22 Inflow 1 Outfall Structure EA 1 $ 8,000 $ 8,000 Subtotal B509-03-00 Detention Basin (166 ac Area at 0.55 ac-ftlac = 91.3 ac-ft Required): $ 617,860 SWPPP Estimated at 10% x Cost 23 SWPPP EA 1 $ 287,509 $ 287,509 Subtotal Option I - Grade 13112-02-00 FL to Drain East & Bridge at Canada St.: $ 3,176,278 25°Io Contingency: $ 794,069 Total Construction Estimate Option JA $ 3,970,347 Note: These estimates are to aid City of La Porte staff for planning purposes only. Unit prices and quantities are approximate and subject to change. Engineering design methods were not performed to develop estimates, presented herein, and shall not be used for bidding purposes. Actual construction estimates shall be determined based on performing professional engineering design services. Klotz Associates Project No. 0 127, 011. 000 13112-02-00 Drainage Study July 2009 2 of 2 City of La Porte Table 2 Option 113 (RCB) Option 1 B - Existing B112-02-00 Grade & RCB's at Canada St Item No. Item Description Unit Estimated Quantity Unit Price Total Cost 1 Mobilize & Prepare Right -of -Way (5% of Total) LS 1 $ 99,613 $ 99,613 B109-03-00 & B109-00-00 Channel Improvements (4,800 LF) 2 Remove & Dispose of Existing Concrete Slope Pavement CY 269 $ 6.70 $ 1,804 3 Excavation (Channel) CY 82,789 $ 4.80 $ 397,387 4 5" Reinforced Concrete Riprap, 2 Slopes at 2:1, Ave. Depth 8 ft, (Include Subgrade Work) CY 994 $ 270 $ 268,328 5 Concrete Low Flow Section (12' wide) CY 1,264 $ 300 $ 379,259 Subtotal B109-03-00 & B109-00-00 Channel Improvements (4,800 LF): $ 1,046,778 Canada St, Bridge over B112-02-00 (RC13s) 6 RC Box's ($580 LF x 5 Barrels) LF 360 $ 580 $ 203,000 7 Remove & Dispose of Existing Concrete Slope Pavement CY 393 $ 6.70 $ 2,630 8 Excavation (Channel) CY 8,711 $ 4.80 $ 41,813 9 Approaches & TCP (Assume 25% of Bridge) LS 1 $ 50,760 $ 50,750 Subtotal Canada St. Bridge over B112-02-00 (RCBs): $ 298,194 13112-02-00 Disconnect & Dam at 13112-00-00 10 Remove & Dispose of Existing Concrete Slope Pavement CY 128 $ 6.70 $ 865 11 Excavation (Channel) CY 366 $ 4.80 $ 1,756 12 Embankment CY 1,170 $ 7.50 $ 8,775 13 124-IN RCP Low Flow outfall Pipe LF 130 $ 50.00 $ 6,500 14 5" Reinforced Concrete Riprap, 2 Slopes at 2: 1, Av. Depth 8.5, (Include Subgrade Work) CY 21 $ 270 $ 5,610 15 Concrete Low Flow Section (16' wide) CY 20 $ 300 $ 5,926 Subtotal B112-02-00 Disconnect & Dam at B112-00-00: $ 29,423 Klotz Associates Project No. 01 27.D1 1.000 B112-02-00 Drainage Study July 2009 1 of 2 City of La Porte Table 2 Option 1 B (RCB) Option 1 B - Existing B112-02-00 Grade & RCB's at Canada St. Item No. Item Description I Unit Estimated I [quantity Unit Price Total Cost B509-03-00 Detention Basin (166 ac Area at 0.55 ac-ftfac = 91.3 ac-ft Required) 16 Detention Excavation CY 147,300 $ 4.00 $ 589,200 17 Interceptor Structures EA 8 $ 2,500 $ 20,660 18 Inflow/ Outfall Structure EA 1 $ 8,000 $ 8,000 Subtotal B509-03-00 Detention Basin (166 ac Area at 0.55 ac-ftlac = 91.3 ae-ft Required): $ 617,860 SWPPP Estimated at 10% x Cost 19 SWPPP EA 1 $ 199,225 $ 199,225 Subtotal Option 18 - Existing B112-02-00 Grade & RCB's at Canada St. $ 2,291,093 25% Contingency: $ 572,773 Total Construction Estimate ❑ tion 1 B: $ 2,863,866 Note: These estimates are to aid City of La Porte staff for planning purposes only. Unit prices and quantities are approximate and subject to change. Engineering design methods were not performed to develop estimates, presented herein, and shall not be used for bidding purposes. Actual construction estimates shall be determined based on performing professional engineering design services. Klotz Associates Project No. 0 127. 011. 000 13112-02-00 Drainage Study July 2009 2 of 2 City of La Pane Table 3 Option 2 Option 2 - Existing B112-D2-00 Grade & City Constructed Detention Item No. Item Description Unit Estimated Quantity Unit Price Total Cost 1 Mobilize & Prepare Right -of -Way (5% of Total) LS 1 $ 123,221 $ 123,221 D1 -14.8 ac-ft Detention at Buyout Location 2 Property at 8807 Gladwyne Ct + 50% (Premium & Demo} LS 1 $ 143,700 $ 143,700 3 Property at 8810 Gladwyne Ct. * 50% (Premium & Demo) LS 1 $ 190,050 $ 190,050 4 Remove & dispose of Existing Concrete Slope Pavement CY 153 $ 6.70 $ 1,024 5 Excavation 1.9 ac. Site wJ HCFCD ROW CY 24,200 $ 4.00 $ 96,800 6 5" Reinf. Conc. Riprap Berm, 20' Wide, 2:1 Slope, Ave. Depth 2 ft, (include Subgrade Work) CY 127 $ 270 $ 34,375 7 Final Grading & SWQ SY 9,196 $ 1.00 $ . 9,196 Subtotal D1 -14.8 ac-ft Detention at Buyout Location: $ 475,145 ❑2 - 91 ac-ft Detention at City Property on Bandridge Rd. 8 Remove & Dispose of Existing Concrete Slope Pavement CY 76 $ 6.70 $ 512 9 Excavation 1.14 ac Site wl HCFCD ROW CY 12,907 $ 4.00 $ 51,627 10 5" Reinf. Conc. Riprap Berm, 20' Wide, 2:1 Slope, Ave. Depth 2 ft, (Include Subgrade Work) CY 64 $ 270 $ 17,188 11 Final Grading & SWQ SY 5,808 $ 1.00 $ 5,808 Subtotal D2 - 8.0 ac-ft Detention at City Property on Bandridge Rd.: $ 75,134 D3 - 26.0 ac-ft Detention at City Property on Somerton Rd. 12 Remove & Dispose of Existing Concrete Slope Pavement CY 311 $ 6.70 $ 2,084 13 Excavation 2.5 ac Site wl HCFCD ROW CY 41,947 $ 4.00 $ 167,787 14 5" Reinf. Conc. Riprap Berm, 20' Wide, 2:1 Slope, Ave. Depth 2 ft, (Include Subgrade Work) CY 162 $ 270 $ 43,750 15 Final Grading & SWQ SY 12,584 $ 1.00 $ 12,684 Subtotal D3 - 26.0 ac-ft Detention at City Property on Somerton Rd.: $ 226,205 Klotz Associates Project No. 0127.011,000 8112-02-00 Drainage Study July 2009 1 of 3 City of La Porte Table 3 Option 2 Option 2 - Existing B112-02-00 Grade & City Constructed Detention Item No. Item Description I Unit I Estimated Unit Price Quantity Total Cost D4 - 7.4 ac-ft Detention at City Property on B109-00-00 16 Excavation 0.8 ac Sitewl HCFCD ROW CY 11,939 $ 4.00 $ 47,755 17 Final Grading & SWQ SY 3,872 $ 1.00 $ 3,872 Subtotal D4 - 7.4 ac-ft Detention at City Property on B109-00-00: $ 51,627 B109-03-00 & B109-00-00 Channel Improvements (4,800 LF) 18 Remove & Dispose of Existing Concrete Slope Pavement CY 269 $ 6.70 $ 1,804 19 Excavation (Channel) CY 57,847 $ 4.80 $ 277,666 20 5" Reinforced Concrete Riprap, 2 Slopes at 2:1, Ave. Depth 8 ft, (Include Subgrade Work) CY 994 $ 270 $ 268,328 21 Concrete Low Flow Section (12' wide) CY 1,264 $ 300 $ 379,259 Subtotal B109-03-00 & B109-00-00 Channel Improvements (4,800 LF): $ 927,057 Canada St. Bridge over 1311.2-02-00 (RCBs) 22 RC Box's ($580 LF x 5 Barrels) LF 350 $ 680 $ 203,000 23 Remove & Dispose of Existing Concrete Slope Pavement CY 393 $ 6.70 $ 2,630 24 Excavation (Channel) CY 8,711 $ 4.80 $ 41,813 25 Approaches & TCP (Assume 25% of Bridge) LS 1 $ 50,750 $ 50,750 Subtotal Canada St. Bridge over B112-02-00 (RCBs): $ 298,194 13112-02-00 Disconnect & Dam at B112-00-00 26 Remove & Dispose of Existing Concrete Slope Pavement CY 128 $ 6.70 $ 855 27 Excavation (Channel) CY 366 $ 4.80 $ 1,756 28 Embankment CY 1,170 $ 7.50 $ 8,775 29 24-IN RCP Low Flow OutPall Pipe LF 130 $ 50.00 $ 6,500 30 5" Reinforced Concrete Riprap, 2 Slopes at 2:1, Av. Depth 8.5, (Include Subgrade Work) CY 21 $ 270 $ 5,610 31 Concrete Low Flow Section (16' wide) CY 20 $ 300 $ 6,926 Subtotal 13112-02-00 Disconnect & Dam at B112-00-00: $ 29,423 Klotz Associates Project No. 0127,011.000 13112-02-00 Drainage Study July 2009 2 of 3 City of La Porte Table 3 Option 2 Option 2 - Existing B112-02-00 Grade & City Constructed Detention Item Item Description Unit Estimated Unit Price Total Cost No, I I I Quantity 8509-03-00 Detention Basin (166 ac Area at 0.65 ac-ftlac = 91.3 ac-ft Req 32 Detention Excavation (Det. Rate = 0.55 ac-ftlac) CY 90,995 (Vt = Vr - Vc = 91.3 - 56.4 = 34.9 ac-ft) 33 Interceptor Structures EA 4 uired) $ 4.00 $ 363,979 $ 2,5001 $ 9,665 34 l Inflow 1 Outfall Structure ] EA i 1 I $ 8,0001 $ 8,000 Subtotal B509-03-00 Detention Basin j166 ae Area at 0.65 ac-ftli ac = 91.3 ac-ft Required): $ 381,634 SWPPP Estimated at 10% x Cost 35 SWPPP I EA 1 $ 246,442 $ 246,442 Subtotal Option 2 - Existing B112-02-00 Grade & City Constructed Detention: 1 $ 2,834,080 25% Contingency: ] $ 708,520 Total Construction Estimate Otrtien 2: I $ 3,542,600 Note: These estimates are to aid City of La Porte staff for planning purposes only. Unit prices and quantities are approximate and subject to change. Engineering design methods were not performed to develop estimates, presented herein, and shall not be used for bidding purposes. Actual construction estimates shall be determined based on performing professional engineering design services. Klotz Associates Project No. 0127.011.000 13112-02-00 Drainage Study July 2009 3 of 3 City of La Porte Table 4 Option Z - Phase I Option 2, Phase 1 - City Constructed Detention Item No. Item Description Unit Estimated Quantity Unit Price Total Cost 1 Mobilize & Prepare Right -of -Way (5% of Total) LS 1 $ 38,824 $ 38,824 01 -14.8 ac-ft Detention at Buyout Location 2 Property at 8807 Gladwyne Ct. + 50% (Premium & Demo) LS 1 $ 143,700 $ 143,700 3 Property at 8810 Gladwyne Ct. + 50% (Premium & Demo) LS 1 $ 190,050 $ 190,050 4 Remove & Dispose of Existing Concrete Slope Pavement CY 153 $ 6.70 $ 1,024 5 Excavation 1.9 ac. Site w/ HCFCD ROW CY 24,200 $ 4.00 $ 96,800 6 16" Reinf. Conc. Riprap Berm, 20' Wide, 2:1 Slope, Ave, Depth 2 ft, (include Subgrade Work) CY 127 $ 270 $ 34,375 7 Final Grading & SWQ SY 9,196 $ 1.00 $ 9,196 Subtotal D1 -14.8 ac--ft Detention at Buyout Location: $ 475,146 DZ - 8.0 ac-ft Detention at City Property on Bandridge Rd. 1 Remove & Dispose of Existing Concrete Slope Pavement CY 76 $ 6.70 $ 512 2 Excavation 1.14 ac Site wl HCFCD ROW CY 12,907 $ 4.00 $ 51,627 3 5" Reinf. Conc. Riprap Berm, 20' Wide, 2:1 Slope, Ave. Depth 2 ft, (include Subgrade Work) CY 64 $ 270 $ 17,188 4 Final Grading & SWQ SY 5,808 $ 1.00 $ 5,808 Subtotal D2 - 8.0 ac-ft Detention at City Property on Bandridge Rd.: $ 75,134 D3 - 26.0 ac-ft Detention at City Property on Somerton Rd. 1 Remove & Dispose of Existing Concrete Slope Pavement CY 311 $ 6.70 $ 2,084 2 Excavation 2.5 ac Site wl HCFCD ROW CY 41,947 $ 4.00 $ 167,787 3 j5" Reinf. Conc. Riprap Berm, 20' Wide, 2:1 Slope, Ave. Depth 2 ft, (Include Subgrade Work) CY 162 $ 270 $ 43,750 4 Final Grading & SWQ SY 12,584 $ 1.00 $ 12,584 Subtotal 03 - 26.0 ac-ft Detention at City Property on Somerton Rd.: $ 226,205 Klotz Associates Project No. 0127.011.000 8112-02-00 Drainage Study July 20D9 1 of 2 City of La Porte Table 4 Option 2 M Phase I SWPPP Estimated at 10°% x Cost SWPPP EA 1 $ 77,648 $ 77,648 Subtotal Option 2, Phase 1 - City Constructer! Detention $ 892,966 21°% Contingency: $ 223,239 Total Construction Estimate Option 2, Phase 1: $ 1,116,196 Note: These estimates are to aid City of La Porte staff for planning purposes only. Unit prices and quantities are approximate and subject to change. Engineering design methods were not per -formed to develop estimates, presented herein, and shall not tie used for bidding purposes. Actual construction estimates shall be determined based on performing professional engineering design services. Klotz Associates Project No. 0127.011.000 13112-02-00 Drainage Study ,rely 2009 2 of 2 City of La Poste Table 5 Option 2 - Phase 2 Option 2, Phase 2 - Channel Improvements & 34.9 ac-ft Detention in B509-03-00 Item No. Item Description Unit I Estimated Quantity Unit Price Total Cost 1 Mobilize & Prepare Right -of -Way (5% of Total) LS 1 $ 76,709 $ 76,709 D4 - 7.4 ac-ft Detention at City Property on B109-00-00 Excavation 0.8 ac Site wl HCFCD ROW CY 11,939 $ 4.00 $ 47,755 Final Grading & SWQ SY 3,872 $ 1.00 $ 3,872 Subtotal D4 - 7.4 ac ft Detention at City Property on B109-00-00: $ 51,627 8109-03-00 & 13109-00-00 Channel Improvements (4,800 LF) 2 Remove & Dispose of Existing Concrete Slope Pavement CY 269 $ 6.70 $ 1,804 3 1 Excavation (Channel) CY 25,813 $ 4.80 $ 123,904 4 15" Reinforced Concrete Riprap, 2 Slopes at 2:1, Ave. Depth 8 ft, (Include Subgrade Work) CY 994 $ 270 $ 268,328 5 Concrete Low Flow Section (12' wide) CY 1,264 $ 300 $ 379,259 Subtotal B109-03-00 & B109-00-00 Channel Improvements (4,800 LF): $ 773,295 Canada St. Bridge over B112-02-00 (KCBs) 6 RC Boa's ($580 LF x 5 Barrels) LF 350 $ 580 $ 203,000 7 Remove & Dispose of Existing Concrete Slope Pavement CY 393 $ 6.70 $ 2,630 8 Excavation (Channel) CY 8,711 $ 4.80 $ 41,813 9 Approaches & TCP (Assume 25% of Bridge) LS 1 $ 60,760 $ 50,750 Subtotal Canada St. Bridge over B112-02-00 (KCBs): $ 298,194 K4otz Associates Project No. 0 127. 011.000 8112-02-00 Drainage Study July 2009 1 of 2 City of La Porte Table 5 Option 2 w Phase 2 Option 2, Phase 2 - Channel Improvements & 34.9 aG-ft Detention in B509-03-00 Item Item Description Unit Estimated Unit Price I I I Quantity Total Cost No. B112-02-00 Disconnect S Dam at B112-00-00 10 Remove & Dispose of Existing Concrete Slope CY 128 $ 6.70 $ 855 Pavement 11 Excavation (Channel) CY 366 $ 4.80 $ 1,756 12 Embankment CY 1,170 $ 7.50 $ 8,775 13 24-IN RCP Low Flaw Qutfall Pipe LF 130 $ 50.00 $ 6,500 14 S' Reinforced Concrete Riprap, 2 Slopes at 2:1, CY 21 $ 270 $ 5,610 Av. Depth 8.5, (include Subgrade Work) 15 Concrete Low Flow Section (16' wide) CY 20 $ 300 $ 5,926 Subtotal B112-02-00 Disconnect & Dam at B112-00-00: $ 29,423 B609-03-00 Detention Basin Excavation - 53.5 ac-ft 16 Detention Excavation (Det. Rate = 0.55 ac-ftlac) CY 90,995 $ 4.00 $ 363,979 {Vt = Vr - Vc = 91.3 - 56.4 = 34.9 ac-ft} 17 Interceptor Structures EA 4 $ 2,500 $ 9,655 18 Inflow I Outfall Structure EA 1 $ 8,000 $ 8,000 Subtotal B509-03-00 Detention Basin Excavation - 53.5 ae-ft : $ 381,834 SWPPP Estimated at 10% x Cost 19 SWPPP EA 1 $ 153,417 $ 153,417 Subtotal option 2, Phase 2 - Existing B112-02-00 Grade $ 1,764,298 25% Contingency: $ 441,074 Total Construction Estimate Option 2 Phase 2: $ 2,205,372 Note: These estimates are to aid City of La Porte staff for planning purposes only. Unit prices and quantities are approximate and subject to change. Engineering design methods were not performed to develop estimates, presented herein, and shall not be used for bidding purposes. Actual construction estimates shall be determined based on performing professional engineering design services. Kiotz Associates Project No. 0127.011.000 B112-02-00 Drainage Study July 2009 2 of 2 City of La Porte 7798 Sa cm I to Legend W Meryl Events O 6112-02-DO & BIOP-DO-00 B112-00-00 LU Own= Stream [ME no 7597.5 7 4183.356 3976.066 i5i6l W 3784.424 ff 115165.61 -, 15162.48 k I otzi,41 associates FEMA FLOOD PLAINS CITY OF LA PORTE Analysis 30a EXHIBIT SCALE: 9 °-20DO, CKI E: j U' Y 2CO9 Ii