Sample the water from the lake and have it analyzed. Chemically treated water may not be the best to use for irrigation. Lakes with excess algae or bacteria may also be undesirable.
Trench the yard for the irrigation system and pump wiring. Use a shovel to dig a narrow trench for the pump wiring leading form the electrical outlet to the pump area. Dig the small ditches for the installation of the irrigation piping. If an irrigation system is already in place, you may skip this part of the step.
Place the pump close to the lake. The pump should be on solid ground which is dry when the lake is at it's highest point.
Run the electric for the pump and bury.
Run piping from the intake of the pump to the lake and from the output to a water filter. Use waterproof sealant to attach the pipes to prevent leaking.
Run piping from the water filter to the irrigation trenches or existing irrigation system.