Head branch of Siahroud River is located in south eastern heights of Qaemshahr City. These heights located near of Caspian beach area. Therefore drainage basin of this river isn't more than 30 Km square.
Initial trend of Siahroud River is east west but with passing from the west of Qaemshahr city it enters the Caspian coastal zone with north south trend. This river cuts Babol Sari road in Km: 17+500
Length of Siahroud River in Caspian coastal zone is about 34 Km in straight line (Total length of this river with its several meander is more than 40 Km). The local base level (LBL) of Siahroud River is -24 m.
Siahroud in hills and heights zone a valley mounds - is a River with straight flow. In the coastal zone However total shape of this river has straight flow but it shows traits of a meander river type.
There are 2 sets of terraces with different plain around the Siahroud River in Caspian coastal zone:
Low plain terrace (H1) with 1-2/5 m height.
High plain terrace (H2) with 4-6/5 m height.
Terraces materials in most sections of river are made by brown Aeolian deposits (loess). Also In some sections medium grain coarse grain alluvial are making terraces.
Artificial levee with more than 1 Km length and 5-6 m height is the important constructions that created in Siahrou River. This levee can be seeing back of cannery factory. This levee has more positive effects in the meanders of river. Until now this levees have had positive effect in separation floodwater flow of this river from building areas.
Siahroud River approximately overflows each year. The most important floodwater of Talar has happened in 1365, 1377, 1382 and 1384. Siahroud river floodwaters are grade 3 in flood hazard. These floodwaters didn't have casualty.
Vulnerable area of Siahroud river can be accounting in 1/5 Km south of Qaemshahr to 1/5 Km north Qaemshahr. in this area Counstruction is plentiful.
One of the important problems in the Siahroud River is the cumulation of building block debris and rubbish around and even bed of river.