Groundwater and baseflow covering aquifers and their properties, gaining and losing streams, governing equations for groundwater flow, baseflow separation, baseflow models, parameter estimation, exponential decay and linear reservoir model.

Drainage is the orderly removal of excess water from the soil surface as well as the soil profile or root zone. It directs the removal in a manner such that it does not erode the soil and damage crops. By so doing it provides a suitable environment for the maximization of plant growth, keeping in mind financial constraints. The objective of this chapter is to present rudiments of agricultural drainage.

Groundwater is of vital importance for agricultural irrigation. In almost all countries, a significant portion of irrigation water is derived from groundwater using wells. In developing countries where farm holdings are small, one well may suffice but a number of wells are used in large farms. This chapter discusses rudimentary aspects of groundwater and wells from the perspective of irrigation. Although the material covered in the chapter is based on gross simplifications, it has been found to be useful nonetheless for irrigation purposes.