area of Semarang. This lowland area is known as the lower town (Semarang Ngisor), as well as the center of the city's economic activity. Under these conditions, the lower city area is often hit by annual flooding and its peak during the rainy season. In a number of regions, especially North Semarang, floods are sometimes also caused by overflowing sea tides (tidal floods). The hilly area in Semarang stretches on the south side. These hills are part of a series of northern Java mountain ranges that stretch from Banten to East Java. The hilly area in the city of Semarang is known as the upper city (Semarang Dhuwur). This hilly region is also the upstream area of the big rivers that flow in the city of Semarang. The upper city area is also near Mount Ungaran. Climate Semarang features a tropical rainforest climate that borders on a tropical monsoon climate (Am). The city features distinctly wetter and drier months, with June through August being the driest months. However, the average monthly rainfall does not fall below , hence the tropical rainforest categorization. Semarang on average sees approximately of rain annually. Average temperatures in the city are relatively consistent, hovering around . Diurnal temperature variation slightly increases in the dry season. Semarang River and flood control Like Singapore River, Semarang is constructing Semarang River at Banjir Kanal Barat (Garang River) near Karangayu Bridge. In the middle of July 2011, gardens in river banks and some traditional boats are available to use. The project will be finished in 2013 with river gardens, trotoars, garden lighting, water activities, art sites, sport sites and balconies and stairs for sightseeing. In August 2011, a tunnel dodger at Kreo river has been finished and Jatibarang Dam construction can begin, with completion targeted for July 2013. The dam is planned to release of flood water and will generate 1.5 MW of electricity, provide a drinking water resource and a boost to tourism. Demographics The largest ethnicity of Semarang includes the Javanese, followed by minorities of Chinese, Indian, Arabic, and others (including local ethnicities such as Sundanese, Batak, Madura, etc.). The dominant religion is Islam. Semarang has a large Chinese community. As in other regions of Java, especially in Central Java, they have mingled closely with the local population and use Javanese in communication for hundreds of years. About 4–5% of the city's population is ethnic Chinese, many