This report outlines the hydraulic infrastructure that should be put up in order to support an urban population. Urban development is accompanied by an increasing need for the supply of potable water, energy, and a drainage system to carry off the waste water and direct storm to reservoirs or other drainage basins. The hydraulic infrastructure enables the supply of clean potable water, which is safe for drinking, and the disposal of waste water and raw sewage in a manner that does not pose threat of waterborne diseases or cause unhygienic conditions. This report provides the details of the components found in hydraulic infrastructure with regard to their functions and operation. The report also explains how the systems are sized in line with the population and the other infrastructure such as buildings that are supported by the system.
The components that make up the hydraulic infrastructure and which are the subject of this report are the municipal potable water systems, water wells, storm water systems including culverts, flow in natural and constructed channels, water-energy nexus, water and waste water treatment plants, sanitary sewers including pressurized and gravity systems, flow in pressurized pipes systems including pumps and pumping, and flow in constructed and natural channels. The engineers mandated with planning the urban development project must incorporate these components into their designs. This report discusses the hydraulic infrastructure components in details to enable the engineer developing the urban settlement plans to come up with a plausible design that can support the population. Also, the information will enable the formulation of a professional hydraulic infrastructure design that is adaptable to the urban development and can accommodate future expansion. Finally, the hydraulic infrastructure design will provide guidance to the engineers developing the urban settlement with regard to the layout of the buildings and other structures. Also, the information shall act as a point of reference for future urban development projects.
Research was done to establish the nature and characteristics of each of the components of the hydraulic infrastructure. The information provided is aimed at helping the engineers design a hydraulic system suitable for the expected population and applications in the urban development project.
Municipal water system
A Municipal water system is primarily used to supply potable water. The system draws water from a water body such as a river or a lake and then purifies it. The purified water is temporarily stored in reservoirs before pumping stations direct it to the consumers through a pipe network. The municipal water system is also linked to drainage basins and sewers. Therefore, the municipal water supply is interconnected with the major components of the hydraulic infrastructure (“Principles of Exterior Drainage” 11). The nature of the municipal water supply system is influenced by the urban development in a big way. The size of the population in the development project determines the capacity of the system. Also, the location of the urban settlement relative to the water source determine the nature of the water supply system with regards to the pipe network, storage, and pumping. Also, the source of water determines the purification system used and the amount of purification done to the water. For example, water from a salty lake requires more purification than water from a fresh water lake. Also, care should be taken to avoid contamination of the water supply with effluents from the drainage and sewer systems. Therefore, the municipal water supply system should be separated and distanced from the drainage and sewer systems. Before the engineers embark on designing the urban development, they should consider the topography of the land to ensure that untreated waste does not flow into the water source in case of leakages. Also, the water supply system should be designed such that water can flow to the point of use through gravity, which minimizes pumping costs.
Surface water runoff estimation, diversion, and routing
Surface runoff is the water that flows on the earth’s surface after heavy rains or due to melting of snow. Water floats on the surface when the soil is fully saturated and cannot soak any more water. The runoff water is responsible for soil erosion and damage of infrastructure such as roads during rainy seasons. Also, as the runoff water flows on the earth’s surface, it collects contaminants such as petroleum, oil, fertilizers, and pesticides that can contaminate the municipal water supplies or pollute water bodies (“Stormwater Conveyance Channel” 7). In addition, the water can cause flooding which can damage property and cause financial losses. To avoid this, the runoff water is channeled to storm water drains and drainage basins. Estimation of the runoff helps town planners to predict snowfall and rainfall that can be experienced in a certain region. The estimated amount of the surface runoff water can then be used in determine the size and type of storm water drainage system. Also, the estimated amount of drainage water and the position of the drainage basin can help planners determine whether the storm water can be harvested for use as part of the municipal water supply.
Flow in natural and constructed channels
Water flows in natural channels due to gravity. Also, water can be redirected to required points through constructed channels. Therefore, natural and constructed channels are essential components in a hydraulic infrastructure. Good understanding of these two channels helps engineers in designing a hydraulic system suitable for a given location. For example, the type of flow in the two channels might be different, either turbulent or laminar flow, therefore, the amount of erosion will be different for the two channels. Turbulent flow can cause damage in a constructed channel, which would necessitate a more robust and expensive structure with high overhead costs. Therefore, the town planners have to understand the type of flow expected in each channel and hence formulate a suitable design in line with the anticipated flow rate. Such kind of knowledge is useful in the design and construction of a channel in a cost effective manner.
Flow in pressurized pipe systems, including pumps and pumping
Pumps are used to move fluids from one place to another against the force of gravity or a pressure gradient. Pumps are powered by electricity or by diesel fuel and are therefore associated with recurrent operation costs. In hydraulic infrastructure, pumps are used to pump potable water into buildings or pump drainage water and treated sewage to points of disposal in situations where the flow is against the force of gravity. There are two classes of pumps, centrifugal and reciprocating, which are determined by the pumping action. Centrifugal pumps have a rotating propeller, known as an impeller, with radial blades which are sometimes slanted at an angle. When the pump rotates, water is sucked from an inlet and forced to an outlet by the centrifugal force. On the other hand, reciprocating pumps pump water through the reciprocating action of the pistons confined in cylinders. Centrifugal pumps are used in applications that require high flow rate while reciprocating pumps are used in high head applications (Wu par.9). The type of the pumping system used in a hydraulic system is determined by the expected flow rates in the system. For example, the potable water supply has to be pumped from the low lying water bodies to the tall buildings in the urban development. To overcome the high back pressure of the water column in the pipeline, reciprocating pumps should be used. Also, the piping system should offer minimum resistance to the flow of water and therefore few strainers should be used in the pressurized pipes. On the other hand, the drainage system has to evacuate large volumes of waste water at very low pressures. Therefore, centrifugal pumps are more suitable in such applications. Also, pipes with large cross sectional areas should be used to accommodate the high volumetric flow rate.
A well is a source of ground water and it is made by boring through the ground. The depth of the well is determined by the depth of the water table or the presence of an aquifer in a given location. Areas with water tables near the surface are suitable for shallow wells while deep seated aquifers can be tapped through the use of boreholes. To supply water from wells to the point of use, pumps are required. The type of pumps used depends on the nature of the well. For example, a deep borehole well requires a rod-shaped submersible pump that can be dipped into the bottom of the well and used to drive the water to an elevated reservoir (Wu par.10). The planners of the urban settlement have to conduct a geophysical study to ascertain the depth of the groundwater and decide whether to drill a deep borehole or a shallow well and select the accompanying water pumping system.
Storm water systems, including culverts
Storm water is the runoff on the ground surface that occurs after heavy rains. A storm water drain is the system used to evacuate the storm water to a drainage basin or a reservoir. Storm water is normally drained in open channels. At the interception of a road and water channel, a culvert is used to protect the intersection from being eroded by the rain water. The urban development shall require culverts to protect the roads’ subgrade from being eroded by the storm water. Therefore, the developers have to consider their plan in terms of the culverts required, their diameter, and length.
Sanitary sewer systems including gravity and pressurized systems
A sanitary sewer is an underground drainage system that is used to channel raw sewage from buildings to treatment plants. The sewer systems are also used for transporting treated waste from the treatment plants to the disposal sites. Sanitary sewers are also used to transport industrial waste water from industrial plants to disposal sites (“Wastewater Technology Fact Sheet.” 5). In the urban development project, the planners will incorporate a sanitary sewer into the hydrological infrastructure to evacuate the sewage waste from the settlement. The size of the sewer system will depend on the number of buildings and the size if the population that the development will support.
Water and wastewater treatment plants
Water treatment plants clean water and purify it for drinking among other uses. On the other hand, waste water treatment plants clean water by removing solid and chemical contaminants to make it suitable for reuse. The repurposed water is then cycled back to the hydraulic system.
The water- energy nexus defines the relationship between energy and water in terms of the amount of water that has to be evaporated to steam to generate a given amount of energy through a turbine. Also, the relationship defines the amount of energy required to harvest, purify, pump, store, and dispose water (“Water for Energy” par.5). In the urban development project, the mechanics of water-energy nexus will determine how much energy is used to pump and purify water in the municipal water supply and the disposal of sewage waste.
“Principles of Exterior Drainage” NDS. n.p. 2007. Web. 26 Jan 2016.
“Stormwater Conveyance Channel” Michigan.gov. n.p., 1 Dec 19992. Web. 26 Jan 2016.
“Wastewater Technology Fact Sheet.” United States Environmental Protection Agency. Municipal Technology Branch, September 2002. Web. 26 Jan 2016.
“Water for Energy.” International Energy Agency. n.p. n.d. Web. 26 Jan 2016.
Wu, Samuel. “Reciprocating Pumps vs. Multi-Stage Centrifugal Pumps” Pumps $ Systems. Cahaba Media Group, n.d. Web. 26 Jan 2016.