Storm Drainage Networks Research Articles

Characterizing Urban Storm Runoff Quality in Dhahran City in Saudi Arabia

The need to increase the water supply of the Kingdom of Saudi Arabia to keep up with the industrial and agricultural development cannot be overemphasized. Several ways exist to enhance the available supplies. One such method is the utilization of storm runoff from urban areas after appropriate treatment. In this study, the possibility of using urban runoff for industrial, irrigation, and other municipal uses after appropriate treatment is investigated. To achieve this, a representative urban watershed in the city of Dhahran was used and the runoff quantity and quality were determined over a four-year study period. The quality parameters considered were suspended solids (SS), total dissolved solids (TDS), alkalinity, hardness, chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), nitrite plus nitrate, phosphorous (P), chlorine (Cl), sulfate, grease and oil, coliforms, and heavy metals. The data obtained on the quantity and quality of the runoff in this city were further analyzed and the levels of treatment required for the various types of uses have been determined. The study showed that SS, COD, and coliforms were the major pollutants. Accordingly, the most feasible alternative is to convert the storm-drainage network to a sedimentation and temporary storage reservoir. If disinfected, the runoff water can be used for restricted irrigation.

How reliable are inlet (hydraulic) models at representing stormwater flow?

It is common practice to base storm drainage network designs on gutter inlet capture information obtained from tests on hydraulic scale models. Growing interest in collection of gross pollution at inlets (‘source control’) is leading researchers to re-visit this domain of hydraulics and to question the reliability of scale models. Results from 0.4-scale and full-size models of a gutter inlet are compared in a laboratory study. Significant differences (up to 40%) were observed in flow captured, the small-scale models showing the lower values. This has important implications for pit spacing and the economics of drainage networks. Performance variation is considered to be the consequence of differences in zones of full and transition turbulence in the two model systems. This explanation is supported by differences being lower for high-flow conditions. These findings sound a warning to those using scale hydraulic models to seek solutions to the problem of ‘at source’ containment of gross pollution.

Evaluation of rainfall characteristics in Bratislava

Statistical characteristics of precipitation in Bratislava, Czechoslovakia are presented. Ten years preceipation records from one gauge was used for statistical processing and then for the long-term simulation of urban runoff. Digitalized rainfall records are available only since 1985. Mainly due to lack of rainfall data with better time and space resolution, the rational method is used for design of storm drainage networks. For the future, it is necessary to unify and update the new calculation methods.

Water Losses from Municipal Utilities and their Impacts

ABSTRACT During the past few years the city of Ar-Riyadh, the capital of Saudi Arabia, has seen a significant increase in urbanization, from a gross residential area of 8,500 ha in 1980 to 62,712 ha in 1990. This 638 per cent increase in urbanization, accompanied by a 91 per cent increase in population (from 850,000 to 1,622,000), has led to a great increase in water consumption that has reached 620 l/cap/day. Most of this water is imported into the Ar-Riyadh environment, but the capability of that environment to dispose of the excess water or wastewater by means of infiltration or evaporation is limited. Consequently the city has begun to experience a rise in the groundwater level that is causing a variety of problems for its citizens. This paper outlines the methodologies and discusses the results from a field study of water losses from the municipal wet infrastructures in six selected areas of Ar-Riyadh that included the potable water the sanitary sewer and the storm drainage networks. More emphasis wa...

Planning Standards for Storm Drainage

Designers of comprehensive storm drainage networks must consider all storm water flow tributary to watershed areas. The presence of governmental boundary lines which do not coincide with these watersheds introduces complicating factors to such designs. Cooperation between engineers responsible for planning in these jurisdictions can produce a unified design result for entire drainage networks. The Kansas City metropolitan area achieves such cooperation by adopting unified design standards produced by local engineers. These standards include accepted criteria for all phases of storm drainage problem analysis and plan preparation. Results of the use of these criteria by agencies throughout the metropolitan area include uniform designs, stage construction of drainage networks, and a more comprehensive understanding by local officials of mutual problem solutions.