The Separate Sewer System

To get knowledge about the runoff, storage and combined sewer overflow (CSO) conditions since 1985 a measuring and monitoring system is working in the sewer network of the community Ense-Bremen (near Dortmund). Within this semi-urban catchment seven detention facilities are fitted out with devices for monitoring information about basin outflow, grade of volume and CSO. Since October 1986 the determined data are also used for the real-time control of that sewerage. Since its installation the monitoring system works rather satisfyingly. Especially the operating staff use its possibilities to get information about the actual condition of the sewer system. Thus, differences to the normal runoff conditions can be realised in very short time. That allows an immediate reaction in order to clear malfunctions or errors as well. However, within the ten years there have also occurred some failures at the measuring devices caused by different reasons up to a complete breakdown of the whole system during thunder-storms. All in all the results of that pilot project have been positive and are now the basis for the equipment of further detention facilities in other sewer systems with monitoring devices.

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Sewer System for Improving Flood Control in Tokyo: A Step towards a Return Period of 70 Years

Water Science & Technology ◽

10.2166/wst.1994.0677 ◽

1994 ◽

Vol 29 (1-2) ◽

pp. 303-310 ◽

Cited By ~ 1

Author(s):

Kazuyuki Higuchi ◽

Masahiro Maeda ◽

Yasuyuki Shintani

Keyword(s):

Return Period ◽

Flood Control ◽

Rainfall Intensity ◽

Runoff Coefficient ◽

Large Drop ◽

Construction Costs ◽

Sewer System ◽

Construction Period ◽

Metropolitan Government ◽

Under Construction

The Tokyo Metropolitan Government has planned future flood control for a rainfall intensity of 100 mm/hr, which corresponds to a return period of 70 years, and a runoff coefficient of 0.8. Considering that the realization of this plan requires a long construction period and high construction costs, the decision was made to proceed by stages. In the first stage, the improvement of the facilities will be based on a rainfall intensity of 75 mm/hr (presently 50 mm/hr), corresponding to a return period of 17 years, and a runoff coefficient of 0.8. In the next stage the facilities will be improved to accommodate a rainfall intensity of 100 mm/hr. In the Nakano and Suginami regions, which suffer frequently from flooding, the plan of improvement based on a rainfall intensity of 75 mm/hr is being implemented before other areas. This facility will be used as a storage sewer for the time being. The Wada-Yayoi Trunk Sewer, as a project of this plan, will have a diameter of 8 m and a 50 m earth cover. This trunk sewer will be constructed considering several constraints. To resolve these problems, hydraulic experiments as well as an inventory study have been carried out. A large drop shaft for the trunk sewer is under construction.

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The Role of Computer Modeling in Combined Sewer Overflow Abatement Planning

Water Science & Technology ◽

10.2166/wst.1992.0627 ◽

1992 ◽

Vol 26 (7-8) ◽

pp. 1831-1840 ◽

Cited By ~ 1

Author(s):

L. A. Roesner ◽

E. H. Burgess

Keyword(s):

System Modeling ◽

Cost Effective ◽

Combined Sewer Overflows ◽

Sewer System ◽

New Techniques ◽

Hydraulic Simulation ◽

Continuous Simulation ◽

Combined Sewer ◽

The U.S

Increased concern regarding water quality impacts from combined sewer overflows (CSOs) in the U.S. and elsewhere has emphasized the role of computermodeling in analyzing CSO impacts and in planning abatement measures. These measures often involve the construction of very large and costly facilities, and computer simulation during plan development is essential to cost-effective facility sizing. An effective approach to CSO system modeling focuses on detailed hydraulic simulation of the interceptor sewers in conjunction with continuous simulation of the combined sewer system to characterize CSOs and explore storage-treatment tradeoffs in planning abatement facilities. Recent advances in microcomputer hardware and software have made possible a number of new techniques which facilitate the use of computer models in CSO abatement planning.

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Sewers and the Quality of Canals and Ditches in Amsterdam

Water Science & Technology ◽

10.2166/wst.1993.0486 ◽

1993 ◽

Vol 27 (5-6) ◽

pp. 61-67 ◽

Cited By ~ 2

Author(s):

E. Jacobs ◽

J. W. van Sluis

Keyword(s):

Water Quality ◽

Surface Water ◽

Sediment Quality ◽

Water System ◽

Water Systems ◽

Sewer System ◽

Water And Sediment ◽

Combined Sewer ◽

Water And Sediment Quality

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.

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