(a) Prepare general hydraulic design of drainage facilities in accordance with the latest edition of the Ohio Department of Transportation “Location and Design Manual, Volume Two, Drainage Design”.
(b) Base storm sewer design on a 10-year storm frequency with the hydraulic grade line checked using a 25-year storm frequency. Use Manning’s “n” value in accordance with the ODOT drainage manual.
(c) Use a 2-year storm frequency to determine catch basin or inlet spacing on all streets. Manning’s “n” used for pavement drainage is 0.015. The maximum allowable spread of flow is six feet into the traveled lane.
(d) The minimum size conduit for culverts, storm sewers and drive pipes is 12".
(e) All culverts (ODOT Type A conduits) shall be rigid pipe meeting the requirements of Item 603 of the ODOT Construction and Material Specifications.
(f) All storm sewer (ODOT Type B & C conduits) and drive pipes (ODOT Type D conduits) shall be rigid pipe or corrugated polyethylene smooth lined pipe meeting the requirements of Item 603 of the ODOT Construction and Material Specifications.
(g) Provide head walls and pipe outlet protection as recommended in the ODOT Drainage Manual. Additionally, provide head walls at the open ends of all drive pipes 24" diameter or greater.
(h) Submit all drainage calculations including catch basin or inlet spacing calculations to the City for review and approval.
(i) Include delineated drainage areas on contour mapping with all drainage calculations submitted for review.
(j) Include pipe under drains on all new roadways and detail sufficiently on plans for contractor to construct under drains correctly.
(k) Include on plans the construction and material specifications for pipe under drains systems.
(l) All drainage calculations to be signed and dated by Registered Engineer.
(m) Refer to City Standard Drawings for additional details.
(n) Two sets of plans and calculations shall be submitted for review.
(Ord. 7-00. Passed 3-9-00.)