Rainwater - /Stormwater application in Sultanate of Oman
The Sultanate of Oman is part of the Arabian Peninsula well known for high temperatures. Due to change in climatic conditions, the region has started to witness and increase in rainfall. The soil is of dry and compact nature therefore unable to absorb the rainwater. This effect is further intensified in the developed areas where buildings, concrete and asphalt prevail. Pictures of the flooded areas are becoming common place and being circulated on the social media.
Remove and repair of the damaged infrastructure requires a lot of effort and money which is a huge burden on the economy of the country which is already facing global economic challenges. Flooding of the sewage system overloads the system and contaminates the clean rain and surface water.
The Sultanate of Oman, in the recent decades, has invested significantly in order to improve water management by building large dams and reservoirs which are operating successfully. But still a large amount of work remains to be completed in achieving total coverage. Similar to the development in Europe where countless stormwater tanks and reservoirs have been developed to ensure that heavy rainfall does not overload the canalization system.
Efficient water management requires using existing water resources, leak-free distribution of water and avoiding contamination of clean water. The contribution of a modern canal system with appropriate dimensions, leak-free joints (to avoid infiltration and exfiltration), and efficient drainage and decentralized water storage cannot be undermined.
Water storage make sense in different ways.
Advantages of Storm-water tanks
- They can be integrated in sewer systems.
- They provide sufficient capacity for rapidly increasing rainwater-quantities.
- They help to avoid flooding of sewer systems, especially during dosed flow to treatment plant.
The rain water can be pre-separated from normal sewage by utilizing smart separation devices in the storm-water tanks.
Storm-water networks & systems:
- Special canal system,
- Over-dimensioned for normal rain and specially designed for heavy rainfalls.
Such systems provide additional capacity that the risk of flooding can be minimized, and these systems can be used in cities and industrial areas.
Water retention tanks:
The best way to utilize rainwater is to catch it up directly and use it commercially, perhaps for irrigation, private or industrial applications. Another interesting application is to use it as a water reservoir for fire fighting systems avoiding the potable water system.
Two applications for storm-water are discussed below:
System: PE 100 storm-water system
Project: Mall of Oman
Location: Muscat, Sultanate of Oman
Client : Majid Al Futtaim Group, Dubai, UAE
Contractor: Sarooj Construction Company LLC, Muscat, Sultanate of Oman
Storm-water system supplier: United Gulf Pipe Manufacturing Co LLC, Muscat, Sultanate of Oman
United Gulf Pipe Manufacturing Co. LLC is the official Krah Pipes producer in the Sultanate of Oman. Krah pipes have clear advantages in easy handling at site, short installation time and the reliability of the joints, using electro-fusion method.
Sarooj Construction Company LLC was awarded the project to construct the infrastructure for the Mall of Oman. Initial design specified GRP pipes and RCC Manholes. The contractor had a prior relationship with the HDPE system supplier and therefore approached UGPM accordingly. UGPM met the requirements as a supplier for KRAH profiled PE 100 pipes for Storm water application for this project.
The pipe sizes ranged from DN/ID 400 – 1800 SN 4, approximately 2.4 kms for this application and 24 manholes of various diameters were supplied for the project. The largest manhole had a diameter of 3000mm, and was produced using a structural shaft using KRAH technology. The manhole had one inlet and outlet of DN 1800 and other inlets of DN 600. It took 2 days to manufacture this large sized manhole at the UGPM factory located in Rusayl Industrial Estate; and only one day to install it at site. UGPM has assisted the contractor to meet the installation before the timelimit and achieved the required objectives of cost savings as compared to product alternatives such as concrete manholes and GRP pipes.
Stormwater system for Mall of Oman, produced by UGPM
Storm-water solution for a new Port
UGPM is a leading supplier in the middle-east market. The pictures below indicate the storm-water network for of a new port and a connected industrial zone. The main contractor wanted to replace the originally planned concrete chambers of the storm-water system with HDPE chambers. UGPM designed and supplied the HDPE manholes and Gully Pot chambers for the network along with pipes for gravity application. A chamber was provided within the manhole in order to avoid the bottom reinforced slabs.
The requirements for the project were as follows:
- Manholes – A traffic load of 90 Tons, and a water table of 1.68 m from ground level
- Gully pot chambers – Traffic load of 90 Tons
Gully Chambers being fabricated and tested for the load carrying capacity before going into production
The Challenge of UGPM was to reduce the contractor’s costs of making the reinforced bottom slab. Manholes were made with a special design which incorporated the bottom (reinforced with stiffner) to provide increased resistance. Additionally, the chamber between the benching and the bottom plate can be filled with the grout. During the installation, blinding concrete was laid before installing the manhole. Then the manhole is placed and grout can be poured between the benching and the bottom plate as shown in the schematic.
Stormwater systems are an essential element of successful and sustainable water management. UGPM provides customized solutions and provides excellent pre and after sales services along with innovative solutions. The durability of PE100 pipe systems and the leak-free jointing system by electrofusion are convincing arguments.
Water is a valuable medium and we need to do all within our efforts to conserve it.
Mohammed Al Hashani
United Gulf Pipe Manufacturing Co. LLC,
Sultanate of Oman