Irrigation of the Hills Golf Course

Due to the legislative ban on wastewater discharges in the Highland Lakes region, golf course irrigation with wastewater effluent goes hand-in-glove with operation of a public water system. The District has a number of contracts with the Hills Golf Course allowing for the disposal of treated wastewater effluent. Conversely, storage of wastewater effluent is essential for operation of the course during the hot, dry summer months, when area lakes are low, drinking water demand is high and the LCRA's water conservation plans may curtail the use of scarce lake water on golf courses.

Irrigation Infrastructure


Hurst Creek MUD's irrigation infrastructure includes a 500,000 gallon per day wastewater treatment plant, a 210,000 gallon surge tank, a 12 inches diameter effluent force main, a 50 million gallon effluent holding pond, and a sophisticated computer-controlled pumping and valving system. The actual irrigation distribution system belongs to the owner of the golf course.

The irrigation system provides for the application to the golf course of effluent stored in the 50 MG pond, or alternately, water from Hurst Creek may be used. However, state law forbids the introduction of the effluent into the creek. Effluent and creek irrigation volumes are separately accounted.

Contracts


The contracts between the District and golf course stipulate that the District will pump water from Lake Travis, as part of its water sale contract with the LCRA, to maintain water levels in Hurst Creek. The golf course may take suction from the creek, but must pay the District for the water withdrawn; in turn, the District must pay the LCRA for creek water used.

In practice, the golf course requires up to 800,000 gallons per day during hot, dry summer days, but virtually none at all during the winter. Therefore, it is essential that the District and the golf course work closely together to manage effluent pond levels; the pond cannot be allowed to exceed its rated capacity of 50 MG and it is equally undesirable to empty the pond before the end of summer, and run short of irrigation supply.

Efflulnt Irrigation


Effluent irrigation typically takes place at night, when the course is closed to play, and large volumes are applied - up to 1,800 gallons per minute - by a network of sprinkler stations spaced throughout the course.

To operate properly, an irrigation distribution system must be kept pressurized at all times, even when sprinkling is not taking place. Additionally, landscape maintenance personnel use irrigation water during the day, but not in sufficient volumes to justify running the District's 250 hp effluent pumps. Because the golf course irrigation system is kept pressurized with water from Hurst Creek on a continuing basis, and effluent from the pond is supplied only during major irrigation cycles, there is an appreciable quantity of creek water used on the golf course in between the major irrigation events. This creek water must be replenished with Lake Travis water, purchased by the District from the LCRA. This lake water usage represents the most feasible opportunity for water conservation efforts. In 2005 this total was 36.02 MG. Replacement of this 36 MG of lake water with effluent is the primary goal for the District's conservation efforts.