Storm Drains. The Engineer shall provide the following services:
1. Design and analyze storm drains using software as approved by the State.
2. Size inlets, laterals, trunk line and outfall. Develop designs that minimize the interference with the passage of traffic or incur damage to the highway and local property in accordance with the State’s Hydraulic Design Manual, District criteria and any specific guidance provided by the State. Storm drain design software shall be selected as directed by the Work Authorization.
3. Determine hydraulic grade line starting at the outfall channel for each storm drain design. Use the design water surface elevation of the outfall as the starting basis (tailwater) for the design of the proposed storm sewer system.
Storm Drains. If applicable to the development, Developer shall construct a storm drainage system in accordance with the Development Plan and Town shall accept the same within the proposed right-of-way lines for ownership and maintenance.
Storm Drains. The Engineer shall provide the following services:
1. Design and analyze storm drains using software as approved by the Owner.
2. Size inlets, laterals, trunk line and outfall. Develop designs that minimize the interference with the passage of traffic or incur damage to the highway and local property in accordance with local drainage ordinances, the TxDOT Hydraulic Design Manual, and any specific guidance provided by the Owner. Storm drain design software shall be selected as directed by the task order.
3. Determine hydraulic grade line starting at the outfall channel for each storm drain design. Use the design water surface elevation of the outfall as the starting basis (tailwater) for the design of the proposed storm sewer system.
4. Calculate manhole head-losses. Compute manhole head losses as per FHWA’s HEC-22.
5. Limit discharge into existing storm drains and existing outfalls to the capacity of the existing system, which will be determined by the Engineer. Evaluate alternate flow routes or detention, if necessary, to relieve system overload. Determine the amount of the total detention storage to control storm drain runoff for the design frequency based on hydrograph routing for the full range of frequencies (50%, 20% 10%, 4%, 2%, 1%, and 0.2% AEP), as well as a rough estimate of the available on-site volume. When oversized storm drains are used for detention, the Engineer shall evaluate the hydraulic grade-line throughout the whole system, within project limits, for the design frequency or frequencies. The Engineer shall coordinate with the Owner any proposed changes to the detention systems.
6. Identify areas requiring trench protection, excavation, shoring, and de-watering.
Storm Drains. There are reserved and granted for the benefit of each Parcel and the Common Area, over, under, across and through the Project, except the Buildings, non-exclusive easements for surface and subsurface storm drains and the flow of water in accordance with natural drainage patterns and the drainage patterns and Improvements installed or constructed by Declarant. Additionally, this Declaration and each Parcel and the Common Areas shall be subject to all easements granted by Declarant for the installation and maintenance of drainage Improvements necessary for the development of the Project.
Storm Drains. The Engineer shall provide the following services:
a. Design and analyze storm drains using software as approved by the State.
b. Size inlets, laterals, trunk line and outfall. Develop designs that minimize the interference with the passage of traffic or incur damage to the highway and local property in accordance with the State’s Hydraulic Design Manual, District criteria and any specific guidance provided by the State. Storm drain design software shall be selected as directed by the Work Authorization. DocuSign Envelope ID: DB60124E-7585-4844-AF91-B8FDD08F857C
c. Determine hydraulic grade line starting at the outfall channel for each storm drain design. Use the design water surface elevation of the outfall as the starting basis (tailwater) for the design of the proposed storm sewer system.
d. Calculate manhole headlosses. Compute manhole head losses as per FHWA’s HEC-22.
e. Limit discharge into existing storm drains and existing outfalls to the capacity of the existing system, which will be determined by the Engineer. Evaluate alternate flow routes or detention, if necessary, to relieve system overload. Determine the amount of the total detention storage to control storm drain runoff for the design frequency based on hydrograph routing for the full range of frequencies (50%, 20% 10%, 4%, 2%, 1%, and 0.2% AEP), as well as a rough estimate of the available on-site volume. When oversized storm drains are used for detention, the Engineer shall evaluate the hydraulic gradeline throughout the whole system, within project limits, for the design frequency or frequencies. The Engineer shall coordinate with the State any proposed changes to the detention systems. The State will assess the effects of such changes on the comprehensive drainage studies.
f. Prepare conceptual 1% AEP sheet flow analysis for the project utilizing existing and proposed conditions if required in the Work Authorization.
g. Identify areas requiring trench protection, excavation, shoring, and de-watering.
Storm Drains. Clean the storm drains prior to the rainy season. Repair storm drains as needed, and remove debris from blocked storm drains. [Transportation and Storm Water Department: Storm Water Division]
Storm Drains. The Engineer shall provide the following services:
a. Design and analyze storm drains using software as approved by the State. DocuSign Envelope ID: F707DECA-9FA0-4A6C-8013-4547938899C1
b. Size inlets, laterals, trunk line and outfall. Develop designs that minimize the interference with the passage of traffic or incur damage to the highway and local property in accordance with the State’s Hydraulic Design Manual, District criteria and any specific guidance provided by the State. Storm drain design software shall be selected as directed by the Work Authorization.
c. Determine hydraulic grade line starting at the outfall channel for each storm drain design. Use the design water surface elevation of the outfall as the starting basis (tailwater) for the design of the proposed storm sewer system.
Storm Drains. Developer shall construct storm drain mains and laterals as required by the Drainage Master Plan and in accordance with the County's then current improvement standards and shall provide laterals to serve all parcels on the Property, including, but not limited to, commercial, multifamily, church, fire station, schools, park and other public sites. Storm drain laterals shall be constructed to the property line concurrently with the construction of connecting open channels or storm drain mains.
Storm Drains. The Consultant shall provide the following services:
a. Design and analyze storm trunklines using SWMM. The Consultant shall design and analyze two drainage systems within the project limits.
b. Size trunk line and outfall. Develop designs that minimize the interference with the passage of traffic or incur damage to the highway and local property in accordance with the State’s Hydraulic Design Manual, Houston District’s criteria and any specific guidance provided by the State. Storm trunk line design software must be SWMM.
c. Determine hydraulic grade line starting at the outfall channel for each storm drain design. Use the design water surface elevation of the outfall as the starting basis (tailwater) for the design of the proposed storm sewer system.
d. Confirm that the post project discharge is fully mitigated. Utilize the models developed from the CivilTech June 2022 Drainage Study for SH 99 to verify that the proposed discharges result in no adverse impact. This is a validation of the original report. The Consultant shall verify the SWMM from the June 2022 report and perform the analysis for the 10-year and 100-year frequency storms for both existing and proposed conditions to ensure no adverse impact to adjacent properties upstream and downstream of the project limits. The work to be performed under this work authorization is limited to analysis and sizing only and does not include design of any proposed infrastructure.
e. Determine the trunkline size for the 10-year design event using the State’s Hydraulic Design Manual. Determine the trunkline upsizing necessary to mitigate for the fill in the floodplain. The June 2022 CivilTech report noted that their analysis did not quantify mitigation for fill in the floodplain, and placed that responsibility on the individual project teams. Using SWMM demonstrate that the oversized boxes do not result in an adverse impact when combined with the ultimate fully mitigated models from the CivilTech June 2022 report models.
Storm Drains. The ENGINEER will provide the following services:
1. Design and analyze storm drains using GeoPak Drainage.
2. Size inlets, laterals, trunk line and outfall. Develop designs that minimize the interference with the passage of traffic or incur damage to the highway and local property in accordance with the State’s Hydraulic Design Manual, District criteria and any specific guidance provided by the COUNTY. Storm drain design software will be selected as directed by the COUNTY’s PM.
