Air locked. Perhaps you need to prime the pump. If there is air in the system it probably cannot suck fluid up from the tank pickup. Use a hose and try to force some water through the system with pressure. Make sure the belt is turning it OK. If necessary, use a water hose and try to force some water backwards from the nozzles through the system. Hoses could be plugged due to sediment, if it was not used in a long time. You can, if needed, replace the hoses with new vinyl tubing. No braided reinforcement is necessary--pressure is low.
Tell us what happened.