मेलम्ची सुरुङको Flushing chamber, drain canal र  outfall structure हेर्नुहोस् ।
Channel: Pusker
Date: 2020-11-17

a gate or sluice used for flushing a channel below the gate in a tunnel, dam or reservoir. 
an artificial canal built to drain water from an area having no natural outlet for precipitation accumulation.Canals are waterways channels, or artificial waterways, for water conveyance, or to service water transport vehicles. They may also help with irrigation. It can be thought of as an artificial version of a river. Canals carry free surface flow under atmospheric pressure.
In most cases, the engineered works will have a series of dams and locks that create reservoirs of low speed current flow. These reservoirs are referred to as slack water levels, often just called levels.A canal is also known as a navigation when it parallels a river and shares part of its waters and drainage basin, and leverages its resources by building dams and locks to increase and lengthen its stretches of slack water levels while staying in its valley.In contrast, a canal cuts across a drainage divide atop a ridge, generally requiring an external water source above the highest elevation.Many canals have been built at elevations towering over valleys and other water ways crossing far below.Canals with sources of water at a higher level can deliver water to a destination such as a city where water is needed. The Roman Empire's aqueducts were such water supply canals.There are two broad types of canal:Waterways: canals and navigations used for carrying vessels transporting goods and people. These can be subdivided into two kinds:Those connecting existing lakes, rivers, other canals or seas and oceans.Those connected in a city network: such as the Canal Grande and others of Venice; the grachten of Amsterdam or Utrecht, and the waterways of Bangkok.Aqueducts: water supply canals that are used for the conveyance and delivery of potable water for human consumption, municipal uses, hydro power canals and agriculture irrigation.This Standard gives guidance on detailing of outfall structures from road drainage systems and design of culverts including scour but excluding hydraulic design. Advice on the hydraulic design of culverts is given in CIRIA 689 Culvert Design and Operation Guide. The guidance given in this Standard relates to adapting the guidance, given in the CIRIA document, specifically for road applications. This Standard contains guidance on the construction of outfalls from road drainage systems to,
principally, natural channels, watercourses, or purpose-made drainage channels. In Ireland, consent is required from the Office of Public Works (OPW), under the Arterial Drainage Acts, 1945 and 1995, for the creation and modification of watercourses, embankments, weirs and bridges. These requirements shall apply to all pre-defined watercourses that fall under the remit of the OPW and take priority over guidance provided in this Standard. Earthworks drainage designed to intercept and convey overland flow approaching National Road projects and perimeter field ditches are understood not to be covered under the scope of OPW requirements and the designer should follow the guidance in this Standard and NRA HD 106 Drainage of Runoff from Natural Catchments for these elements.The term outfall is applied to the point where the road drainage system discharges into a different type of drainage system: this maybe natural channels, watercourses, or purpose-made drainage channels. For the purposes of this Standard, outfalls are to either ditches or receiving watercourses. Determine or estimate the top water level in the receiving watercourse or ditch channel for the corresponding design storm applicable to the road drainage system design (NRA HD 33). The invert level of the outfall pipe should be at or above this level. The top water level of the receiving watercourse or ditch should then be assessed for more intense storms up to a 1 in 100 year storm event to determine the extent of any adverse impacts compared with the existing scenario.