Water is also very necessary for industrial activities, fisheries, agriculture and other
businesses. In the use of water, there is often a lack of caution in its use and utilization,
so efforts are needed to maintain a balance between the availability and demand for
water through development, preservation, improvement and protection. The purpose of
this study was to analyze the need and availability of irrigation water in order to obtain
a balanced irrigation system. The data collected are weather adjustment factors due to
day and night, solar radiation, saturated vapor pressure, real vapor pressure, wind
function, percolation, rice crop coefficient, effective rainfall and water layer changes.
The data was obtained from the Pemali - Juana River Regional Office, namely the water
resources agency under the PUPR ministry whose job is to manage the irrigation
facilities through which the Pemali Juana river passes. Brebes is one of the regencies
that are in the Pemali Juana BBWS service. Based on the results of the analysis of these
data, it is calculated using the modified and manual penman method (concept KP-01)
to obtain the average calculated value from the Need for Irrigation Water (IR) in one
year of 21.90 mm/day, and the Need for Intake Water (DR) of 14.351,69 l/sec.