By James Gregory

Sean Hoolehan, the superintendent atthe Koolau Golf and Country Club onthe windward side of Oahu in the

Hawaiian Islands, is playing a waiting game.He's waiting for the Penncross bentgrassand the 328 hybrid berrnudagrass to finishgrowing in this October at the new club.

Koolau will have its grand opening nextyear, though some light playing is alreadytaking place. By then the clubhouse will beready to welcome golfers to the exclusivecountry club being built by Minami GroupUSA, a Japanese company.

Extensive erosion controlwas necessary to meet the

opening deadline. Hole growing inthis past March (left).

Erosion devices in place onNovember 1990 (right).

Hydromulching, blankets, siltfences, and sand bags held the

sprigged turf in place.

8 Golf & sport TURF

It's a breathtakingly beautiful site for agolf course, situated at the foot of theKoolau Mountains that divide the leewardand windward sides of Oahu. A dozen or so"disappearing" waterfalls suddenly appearduring rain showers, enhancing the manystreams on the emerald-green landscape,and then abruptly vanish soon after the rainhas abated.

The Koolau Golf and Country Club hasa prime location, carved out of a tropicalrain forest below the windswept Pali Look-out known to all tourists. However, the

weather at Koolau posed a real erosionthreat to the course during and after con-struction. Fortunately, everyone involvedwas prepared, the club's young superinten-dent reveals.The Road to Hawaii

Hoolehan is a native of the Midwest andcompleted a specialized two-year programin turfgrass management at Rutgers Uni-versity in New Brunswick, NJ. His first golfcourse job as assistant superintendent at aclub in Hinsdale, IL, where he met DickNugent, the golf course architect for the

Hawaiian club. Nugent was impressed byhis knowledge of bentgrass and later rec-ommended him to the owners at Koolau.By that time, Hoolehan was the superinten-dent at the golf course on the militaryreservation at Pearl Harbor, on the otherside of Honolulu from Koolau, and hadbecome very familiar with the unique prob-lems caused by the Hawaiian weather.

"Construction here began in 1988,"says Hoolehan, "and I came on board in1989. We just wrapped up construction thisspring, and now we're busy with the grow-in. Winter is our rainy season here, and nota great time to establish berrnudagrass. Weonly have about five months of optimumberrnudagrass weather. But it should belooking good in October. We already havesome light play on the course, even thoughwe won't have our grand opening untilapproximately March of next year."

Stormy WeatherHoolehan confides, "We have an excep-

tional erosion problem here. The last twoyears, we've had over 130 inches of raineach year! We've done a lot of differentthings to try to control erosion, and we'vebeen fairly successful with the differentmethods.

"Hazama Corporation was the generalcontractor and Wadsworth Golf CourseConstruction Company was the golf coursefeature contractor. They were very cooper-ative about getting the erosion control ma-terials down in a timely manner. But theirresponsibility stopped right after grassing.They had to basically sprig the course, andwe accepted the project from there.

"The first hole was turned over to usback in August of last year, and the lasthole-actually, the driving range-was turnedover about the middle of April this year,"he notes. "Once Wadsworth had grassedand capped the course, then it was ourresponsibility to water it."

How Hydromulch Helped"The contractor didn't have any respon-

sibility for erosion control once the sprigshad been planted. We were presented witha site that gets a tremendous amount ofrain in the wintertime. Our program was tocome in behind the contractors, or some-times alongside of them, and do variousmethods of erosion control. Often therewould be a small overlap. For instance,we'd be putting our materials down, andthey would hydromulch over that material.The hydromulching, which was done byWadsworth, was more to keep the sprigsmoist than to control erosion," Hoolehancomments.

In case you're wondering why the sprigshad to be kept moist in an area that aver-ages almost half an inch of rain a day,Hoolehan has a ready explanation. "Itmight rain half an inch in the morning andthen be bright and sunny for the rest of theday. Young sprigs don't have much of aroot system, and the tropical sun and windscan dry them out quickly."

On some occasions, the hydromulch hadberrnudagrass mixed into it for the verysteep slopes that could not be planted anyother way, Hoolehan explains. When you'reworking with a mountain, you learn toadapt to it-but the results can be beautifullyrewarding.

Bunker slope lined with double netted strawblanket.

Instant Waterfalls"When it rains, cutoff ditches above the

club keep the water on the mountainsidefrom rushing down onto the course,"Hoolehan explains. "From the cutoffditches, it runs down a whole series ofbeautiful streams. You might see a dozenor more waterfalls on the mountain abovethe course during a rain shower, and noneafter it finishes raining."

Working in such changeable weatherconditions made it more important thanever to work in concert with the contractor."Their operation would go something likethis," says Hoolehan. "They'd do all theirforming on the hole, grading and rakingand putting in the amendments. And thenthey would plant the sprigs. They wouldeither use a sprigging machine or handsprig difficult areas, like around the greens.Only the bentgrass greens are seeded. Therest of it is all 328 hybrid bermuda."

Hoolehan continues, "After that, theywould go back and put a hydromulch capover all their grass, within an hour or twoafter they had planted it. Then at that pointit became the responsibility of the owner.

"Our problem was that we might getrains of more than an inch an hour duringthe winter. There were periods where wehad 20 inches of rain over a 24-hour period!Between mid-November, 1990 and the endof December that same year, we had 45 to50 inches of rain. Warm air comes in off theocean, hits the mountain, goes up, meetscold air, and the result is rain. Not justrain-buckets of it.

continued on page 10

June, 1991 9

Superintendent Sean Hoolahan (r) and Gilbert Araki from Pacific Agricultural Sales look overgreen protected by blankets and silt fence.

Koolau Golf and Country Clubcontinued from page 9

Erosion Control Strategies"So we used a number of different ero-

sion control materials that we found avail-able," Hoolehan continues. "Our mainsource was North American Green. They

supplied three different types of erosioncontrol blankets made of nylon netting thatcontained straw and solid coconut fibers."

Before the blankets were installed thesprinkler system was run for a short timeafter final grading to reveal potential prob-lem areas on each hole. A plan was then

developed to provide high-performanceerosion control where needed.

The rainfall, much of it coming down attremendous intensities, was not the onlyproblem. The silty clay volcanic soils whichdominate the site are easily eroded. In fact,says Hoolehan, "Irrigation alone is enoughto create erosion."

Double-netted straw erosion controlblankets were installed on steep undula-tions and bunker faces to control soil lossand hold sprigs in place. A heavy-duty blan-ket made from a combination of wheatstraw and coconut fiber was used to linedrainage swales and cover steep slopes. Forthose high-flow channels designed to carryrunoff water from large drainage areas on 'the course, the coconut and nylon channelliners provided maximum scour protection."Wherever we successfully used the ero-sion control blankets, we had good compac-tion of the soil first," says Hoolehan.

At Koolau, only 10 percent of the totalcourse area required erosion control blan-kets to ensure the stability of the meticu-lously sculpted landscapes. The remainingacreage was hydro mulched to cover thesprigs and hold moisture. Although blan-kets may initially cost more than otherforms of erosion protection, Hoolehan be-

10 Golf & sport TURF Cirde 105 on Postage Free Card

•• 1111111••

Silva-Fiber;100%VIrgin Wood Fiberfor Hydraulic Planting

• Erosion Control• Reclamation

• Re-vegetation...... Turfgrass

~" .. ,

. \ ....... :~.:.:~\\ 'Z,.

"\', ,\.,,~ ..

Call or writefor FREE

Specifiers' Guideand/or video information

(800)-443-9179

~ VVeyerhaeuserEF-4 Tacoma, WA 98477

Cirde 106 on Postage Free Card

lieves a little extra effort up front is cheaperin the long run: "If you get grass estab-lished the first time, you don't have to goback."

Hoolehan's theory was substantiatedthrough a comparison of the first and sec-ond fairways of the Koolau course aftererosion control measures were applied. Onthe first fairway, where hydromulch pro-vided the only protection, a two-foot-by-200-foot gully was formed by rainfall andirrigation runoff. It required expensive re-working and reshaping of the landscape.

On the second fairway, where erosioncontrol blankets were used, no significanterosion occurred. According to Hoolehan,"If we had not used blankets on the secondfairway, the amount of finish work wouldhave been a lot greater. Since the blanketseffectively controlled the erosion, we canconcentrate our efforts on fine-tuning thehole."

Annual Ryegrass Also WorkedRyegrass was another useful choice in

staving off erosion, says Hoolehan. "Onvery severe slopes of three to one andgreater, we used annual ryegrass to stabi-lize the soil in the winter months until thebermuda became strong enough to fill in.We also used ryegrass to fill in a lot of otherareas until we could come back and reveg-etate them to the natural conditions thatexisted before the construction. The rainyseason is not a very conducive time toestablish bermuda. The grass doesn't godormant in Hawaii, but the sprigs don'tstart to spread because of the cooler tem-peratures and shorter days.

"We're right on the side of a mountainthat casts a tremendous amount of shadeon the golf course in winter," Hoolehannotes. "That's one of the reasons we wentwith bentgrass greens. Berrnudagrasswouldn't have made a very good greenssurface in Winter, but we feel that for fair-ways, tees, and roughs the bermuda will befine. We expect the course to be playable inthe winter despite the rain.

"We've imported silica sand from Aus-tralia for the greens construction, becausewe couldn't get as good a sand here," saysHoolehan. "Most sands in Hawaii are basi-cally coral, and marginal for use in greensconstruction."

Protecting the EcologyFor ecology's sake, "we had a grading

permit that only allowed us to clear 15contiguous acres. We had to selectivelyclear the golf course, because it's a sensitivearea around her, We tried to eliminate all

the runoff we could from the golf course,in order to help control the erosion,"Hoolehan recalls.

"Although we had a lot of rain duringthe construction phase, the contractor builtlarge siltation basins to protect against therunoff of silt from the project He alsoutilized silt fences and other material. Butas I said, that was not my responsibility,"he notes. "My job was to worry abouterosion control after construction, notwhile it was underway."

As soon as they have grown them in, itwill be the responsibility of the grasses to

keep erosion under control, Hoolehan ob-serves. The golf course superintendent hasevery confidence they'll be up to the task.If they do as good a job as he and thecontractor have done, Koolau Coif andCountry Club should be making its formaldebut next spring intact and on schedule.It should fit beautifully into its spectacularsurroundings, with no harm to the delicateecology.

"Before this course was built, the areawas a tropical rain forest," says Hoolehanwith a smile. "Now we have a country club,and the rain forest is still here!"

As the game of golf grows, so does the demand for Hydro-Plant.We provide golf courses all over California with seeding, erosioncontrol and stolonizing, and one other very important feature thatnever grows old - first class service.

If you're considering the services of a hydroseeding company,give us a call and we'll refer you to some golf course superintendentswho've grown accustomed to our way of doing business.

~ HY~'::':o-,~~~':!,f~JInc.356 South Pacific St., San Marcos, CA 92069·619/744-7360 ·714/351-4343 • Fax 619/744-6559

Circle 121 on Postage Free Card June, 1991 11