Baseflow is essential for water resource management in the dry season at the watershed scale. Management strategy water resources play a crucial role, especially those related to estimation efforts water supply, water quality management, water balance calculation, and strategy development of other water resources. This study aims to determine the value of baseflow using the Fixed Interval Method. This study used Hydro Office software with input daily discharge data from 2004 to 2013. The average baseflow value obtained was 5.53 m3/s, the process of calibrating by taking discharge data in the dry season, with no rainfall input. The BFI value obtained an average of 0. 9. This value indicates that the Miu watershed has high storage permeability characteristics. It indicates that the Miu watershed has a relatively stable flow during dry periods. The greater the BFI value, the better the water supply in a watershed.

The high sediment contained in the canals causes changes in the dimensions of the canals. It can reduce the cross-sectional capacity of the canals. The Baluase Irrigation Area is located in Sigi Regency, Central Sulawesi Province, with a functional area of 94 Ha. This study aims to determine the rate of sedimentation in the Baluase Irrigation Secondary canals, which is expressed in the correlation coefficient (R), which is the relationship between Sediment Discharge (Qs) and Water Discharge (Qw). Primary data were collected by direct measurements at the location by measuring canals dimensions, water level, velocity and water samples to test sediment concentration. Sediment samples were taken at 2 distances of flow depth, namely 0.2 h and 0.8 h with 8 cross sections in the longitudinal direction of the canal. From the research results, the average sedimentation rate in the Ramba secondary canal is 3,574 kg/day, while the Baluase secondary canal is 5,675 kg/day. The correlation coefficient (R) value at 0.2 h was 0.6994 and 0.8229 for a depth of 0.8 h. This shows that the relationship between sediment discharge (Qs) and water discharge (Qw) has a positive relationship between 0.6 < R < 1.0

Hydrograph is a way of predicting the amount of flood discharge plans in a watershed. Each watershed has different drainage characteristics due to the topographic shape of the watershed, land use, river typology (length, number, and slope), height and duration of rainfall. This research was conducted in Palu River Basin, with a basin area of 3. 060,388 km2, mismatch analysis of watershed and synthetic unit hydrograph, rain and discharge analysis, hydrograph discharge design analysis using optimal synthetic unit hydrograph parameter model. From the results of research calculation of Synthetic Unit Hydrograph Nakayasu Method has big enough key compared with another method. By using hydrograph model of flood plan for Palu River Watershed with the approach of Synthetic Unit Hydrograph Nakayasu, hydrograph calculation of flood in Palu river watershed, obtained alpha coefficient equal to 0,651 and Tr coefficient 0,3 with cash value model 71,491%. with cash value model 71,491%.