The URL can be used to link to this page

Home My WebLink AboutContract 39856-A1 CITY SECMTAW CONTRACT NO. _ AMENDMENT No.1 TO CITY SECRETARY CONTRACT No. 39856 WHEREAS, the City of Fort Worth (CITY) and Dunaway Associates, LP, (ENGINEER) made and entered into City Secretary Contract No. 39856, (the CONTRACT) which was authorized by M&C C-23938 on the 8th day of December, 2009 in the amount of $212, 115 . 00; and WHEREAS, the CONTRACT involves engineering services for the following project : Ridglea Creek and Luther Creek Master Plan; and WHEREAS, it has become necessary to execute Amendment No. 1 to the CONTRACT to include an increased scope of work and revised fee. NOW THEREFORE, CITY and ENGINEER, acting herein by and through their duly authorized representatives, enter into the following agreement, which amends the CONTRACT: 1. Article I of the CONTRACT is amended to include the additional engineering services specified in a proposal dated September 18, 2014, a copy of which is attached hereto and incorporated herein. The cost to City for the additional design services to be performed by Engineer totals $49, 155 . 00 . 2 . Article II of the CONTRACT is amended to provide for an increase in the fee to be paid to Engineer for all work and services performed under the Contract, as amended, so that the total fee paid by the City for all work and services shall be an amount of $261, 270 . 00 . 3 . All other provisions of the Contract, which are not expressly amended herein, shall remain in full force and effect . City of Fort Worth OFFICIAL RECORD Professional Services Agreement Amendment Template CITY SECRETARY PMO Official Release 8/1/2012 Page 1 of 2 FT. WORTH,TX DUNAWAy Dunaway No. 2007367.001 September 18,2014 Mr. Steve Eubanks, P.E. Senior Professional Engineer City of Fort Worth TPW—Storm Water Management Division 1000 Throckmorton Fort Worth,TX 76102 Reference: Contract Amendment#1 — InfoWorks Modeling Ridglea Creek and Luther Creek Open Channel Study City Project No. SWS-022 City Secretary Contract No. 39856 Dear Mr. Eubanks: Per your email of August 4, 2014, transmitted herein is a revised scope of services for Contract Amendment No. 1 to the Ridglea Creek and Luther Creek Open Channel Study project. Per the discussion, the following summarizes the effort included in this amendment: • Effort required for initial InfoWorks SD modeling that was outside original scope performed to date • Additional field surveying data in overflow areas to provide accurate topography • Conversion to and development of a single InfoWorks ICM model for the entire project area (one seamless model, with HEC-HMS data included, rather than patches of HEC-RAS and InfoWorks) This letter constitutes our request for supplemental authorization for tasks outside the scope of services of our current contract(City Project No. SWS-022). FEE Dunaway Associates, L.P. proposes to provide the scope of work described herein for a LUMP SUM fee of$49,155, based on the following anticipated break-down: M Total M. rVV 1. Original Contract $212,115 nor 2. Amendment#1 —InfoWorks ICM Analysis $ 49.155 0 TOTAL BUDGET $ 261,270 ° OFFICIAL RECORD V CITY SECRETARY FT. WORTH Tit 550 SailevAvenue, Suite 400 ! Fort Worth, Texas 76107 ! TPi: 817.335.1121 1 Fax: 81 7.335.7437 ! durowayassocates,com Contract Amendment #1 — InfoWorks Modeling City Project No. SWS-022 September 18, 2014/Page 2 SCOPE OF WORK TASK 1 PROJECT MANAGEMENT With the extension of the project schedule needed to accommodate the additional effort describe in this Scope of Services, Consultant will prepare the following: a. Project Status Reports — Eight (8) additional project status reports. b. Invoicing — Eight (8) additional monthly invoices. TASK 2 DATA COLLECTION / FIELD SURVEY The following items shall be added to those included in the original contract: a. Dataset Search and Collection — No change. b. Field Reconnaissance— No change. c. Stream Condition Assessment— No change. d. Field Surveys — Additional topographic data will be obtained in the intersections of Plum Valley Place and Edgehill Road with Westridge Avenue. The additional data will be added to the InfoWorks model for determining surface flow direction at the intersection. e. Finished Floors — Additional finished floor elevations will be collected for properties that were not included in the initial finished floors survey and are in close proximity to the overflow areas identified in the initial InfoWorks modeling (Exhibit A). ASSUMPTIONS: • Topographic survey area is limited to the right-of-way only at the intersection of Plum Valley Place and Edgehill Road with Westridge Avenue (approximately 13,880 square feet), and will include top of curb, gutter, street centerline (crown), right-of-way elevations, as well as other topographic features that will impact direction of storm water flow. • Thirty-six (36) finished floor elevations will be obtained. TASK 3 DEVELOPMENT OF DETAILED HYDROLOGIC MODELS Due to the complexity of the hydraulics at the lower end of the Ridglea Creek watershed, the data in the HEC-HMS hydrologic model was used to create an InfoWorks model of the watershed. The initial model was created in the InfoWorks SD format, but was subsequently update to the InfoWorks lCM format to better more accurately model channel flow. 2007367_Amendl_2014-091 B.docx 550 Bailey Avenue,Suite 400 a Fort Worth,Texas 76107 -*Tel:817.335.1121 a Fax:817.335.7437-dunawayassoclates.com Contract Amendment #1 — InfoWorks Modeling City Project No. SWS-022 September 18, 2014/Page 3 a. InfoWorks SD Hydrologic Modeling — Consultant developed an InfoWorks SD 2D hydrologic model to accurately model the surface flow that occurs in the lower portion of the Ridglea/Luther Creek watershed. The following tasks were completed to model the hydrologic conditions for the open channel study: 1. The hydrologic data developed for the HEC-HMS models were input into the InfoWorks SD model, 2. Several sub-watersheds limits were redefined to reflect contributing areas at the respective storm drain inlets, and 3. The travel times within the revised sub-basins were computed to reflect the adjusted basin configurations. b. InfoWorks ICM Hydrologic Modeling —The InfoWorks SD model will be converted to the InfoWorks ICM format to more accurately compute storm water flow within the channel areas. 1. Conversion to InfoWorks ICM — Consultant will convert the existing InfoWorks SD model developed for the Ridglea/Luther Creek open channel study to the InfoWorks ICM format to accommodate the addition of the open channel areas between the various pipe segments into a single model. 2. Hydrologic Model Refinement — Consultant will divide the Ridglea/Luther Creek watershed into sub-basins consistent to accurately represent the stream reaches in the combined InfoWorks hydrologic/hydraulic model. TASK 4 DEVELOPMENT OF HYDRAULIC MODELS AND FLOODPLAIN MAPS The hydraulic stream data will be combined with the InfoWorks hydrologic data for form a single model. a. InfoWorks SD Hydraulic Modeling — Consultant developed an InfoWorks SD 2D hydraulic model to accurately model the surface flow that occurs in the lower portion of the Ridglea/Luther Creek watershed. The following tasks were completed to model the hydrologic conditions for the open channel study: 1. The hydraulic data developed for the HEC-RAS models were input into the InfoWorks SD model, 2. Existing storm drain and culvert data were input into the InfoWorks SD model and the 100-year water surface elevation was computed for the area where surface flow was anticipated, and 3. The approximate 100-year flooding limits were delineated. 2007367_Amendl_2014-0918.docx 550 Bailey Avenue,SuRe 400 @ Fort Worth,Texas 76107 4 Tel:817,335.1121 0 Fax:817,335.7437 0 dunawayassoclates.com Contract Amendment #1 — InfoWorks Modeling City Project No. SWS-022 September 18, 2014/Page 4 b. InfoWorks ICM Hydraulic Model Development — Consultant will develop a single hydraulic model that contains both the Ridglea and Luther Creeks open channels, as well as the closed system components identified in Task 2. The combined model will result in a single model that seamlessly analyzes the hydrologic and hydraulic conditions of both the open channels and the closed systems between open channel segments. The hydraulic model will also include surface flow components in areas where storm water exceeds the available open channel and closed system capacities. 1. Open Channel Data —Topographic data obtained in the field surveys will be added to the InfoWorks ICM model to represent the open channel areas that were not included in the initial phase of the study. 2. 2D Mesh Development — The 2D mesh of the initial InfoWorks SD model will be incorporated into the InfoWorks ICM model and refined to accommodate new data obtained for the project. 3. Update Results for Existing Conditions — The InfoWorks ICM model will be used to compute flood elevations within the Ridgle/Luther Creek watershed, within both the open channel areas and in upstream areas were the system is enclosed. The listing of existing flood hazard areas will be updated with the results of the InfoWorks ICM modeling. TASK 5 WATERSHED FLOOD HAZARD ASSESSMENT Dunaway will update the initial flood hazard assessment data developed for the Ridglea/Luther Creek watershed with the data generated from the InfoWorks lCM model. a. Assess Capacity of Stream Crossings — Utilize the InfoWorks model to verify the initial findings of existing stream crossings capacity to convey the 100-year frequency storm water flow. b. Finished Floor Elevations - Expand the initial comparison of floodplain and finished floor elevations to the areas added with this amended scope. TASK 6 PROPOSED FLOOD MITIGATION ALTERNATIVE ANALYSIS Since the InfoWorks software is more complex than the HEC-HMS and HEC-RAS software, additional effort will be required to revise the existing conditions InfoWorks model to reflect possible flood mitigation alternatives than was originally anticipated by modifying the HEC-HMS and HEC-RAS models. a. Mitigation Alternatives — Using the InfoWorks ICM model, develop one (1) conceptual improvement option for the areas within the Ridglea/Luther Creek watershed where the 2007367 Amend1 2014-091B.docx 550 Bailey Avenue,suite 400 --- Fort Worth,Texas 76107 ---Tel:817.335.1121 ---Fax:81 7.335.7437 0 dunawayassociates,com Contract Amendment #1 — InfoWorks Modeling City Project No. SWS-022 September 18, 2014/Page 5 existing 100-year frequency storm water discharge is shown to exceed existing easements/rights-of-way. b. Submit Mitigation Alternative Analysis Findings 1. Letter Report — Submit a letter report summarizing the findings of the updated flood hazard assessment and proposed mitigation alternatives to the City. 2. Review Meeting — Attend one (1) meeting with the City to discuss the proposed mitigation alternatives. c. Update Proiect Report—Adjust the proposed mitigation alternatives per the City's review comments following the mitigation alternative review meeting and incorporate the revised mitigation alternatives into the overall project report. TASK 7 QUALITY ASSURANCE AND QUALITY CONTROL PROCEDURES a. Quality Assurance And Quality Control For The Extended Proiect — Consultant will perform a second QA/QC review of the items performed for Tasks 2, 3, 4 and 5, in addition to the QA/QC review performed for the initial effort. Please do not hesitate to call us if you have any questions or require additional information regarding this proposal. Respectfully submitted, DUNAWAY ASSOCIATES, L.P., a Texas limited partnership ;��g Michael J. Dell s, P.E., CFM Toby K. Ford, P.E. Associate/Water Resources Director Vice President Attachment 2007367 Amendl 2014-0918.docx 550 Balley Avenue,Suite 400 0 Fort Worth,Texas 76107 @ Tel:817.335.1121 0 Fax:817.335.7437 v dunawayassoclates.com _ I 0 100 200 1 inch = 200 feet I, s '�# I _ n LU Y ' ` EXHIBIT A r SURVEY DATA " - NEEDED . p1 . . RIDGLEA CRK./LUTHER CRK. - OPEN CHANNEL STUDY FORT WORTH,TEXAS Legend ,�- k September 2013 Q Topographic Survey Needed " _+ FORT WORTH € Finished Floor Elevation Needed CIE Previous Finished Floor Survey .` + E __ � E-w -D UNAWAY .t I rF, a, sy m ��..� X01 .1. .na} .nors