Jamshid Abad River is eastern branch for Daniyal River and it cuts Tonekabon-Chalus coastal road in km: 36. Area of drainage basin for Jamshid Abad River is part of drainage basin (40 km2) for Tileh Rud and Daniyal rivers. Local base level (LBL) of Jamshid Abad River is -25 meter and its gradient is 7/1000 in Caspian beach plain. Maximum width of stream-bed is about 100 m and its minimum width of is 10-15 m.
Jamshid Abad stream flow is direct that there are several meander in its flow path. Index of meander for this stream is low to mean. Floodwater causes under cutting and slide of stream walls.
There are 2 groups of river terraces in beach plain for Jamshid Abad stream:
- H1 (river terraces with down surface level): 20-year boundary of flood plain (Height: 2 m)
- H2 (river terraces with high surface level): 50 or 100-year boundary of flood plain (Height: 4-5 m)
Materials of terraces wall are mainly Aeolian (Loess) with fine-grained alluvium.
Stream flood of Jamshid Abad River happens approximately yearly, but floodwaters for years of 1350, 1375, 1379 and 1381 were the most devastating floods of this river.
Vulnerable area of Jamshid Abad River lies between 1.5 km of southern and 200 m of northern Jamshid Abad. Width of active flood plain is 30-40 m. There are maximum damages due to floodwater flow in bights of river.
Mitigation plans of floodwater:
- Dredging of stream-bed by municipality yearly (Dredging in place of Jamshid Abad bridge especially)
- Construction of concreting wall with length: 500-600 m in southern boundary of vulnerable area for Jamshid Abad River
- Limitation for building in active flood plain of river and restrain of extraction from borrow material of stream-bed
- Generation of large scale map and determination of active flood plains exactly