ARS | Publication request: Curve Numbers for Golf Course Watersheds

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 11, 2008
Publication Date: June 23, 2008
Repository URL: http://hdl.handle.net/10113/19598
Citation: King, K.W., Balogh, J.C. 2008. Curve Numbers for Golf Course Watersheds. Transactions of the ASABE. 51(3):987-996.

Interpretive Summary: The number of golf courses in the US and abroad is continually increasing. Environmental hydrology issues such as structural design and water quality on and surrounding the golf courses will have to be addressed. One approach at determining the design hydrology is a method known as curve number, a simplistic but robust method used to project the amount of discharge resulting from a specific rainfall event. Curve numbers have been suggested for a variety of land uses including turfgrass. However, the turfgrass curve numbers were derived from small homogeneous plots and are not applicable to watershed scale managed turf systems. Curve numbers were derived for two watershed scale golf courses with different physical and climatic attributes. The findings suggest that existing recommendations for curve numbers for turfgrass may not be appropriate for watershed scale golf course systems. This research will provide hydrologists, design engineers, and modelers faced with structural design issues or water quality concerns on or in the vicinity of golf courses with more reliable curve numbers.

Technical Abstract: Storm event runoff is a critical component to the environmental and structural design related to hydrology. The curve number (CN) method is a robust and accepted method for determining excess rainfall. Measured CNs for golf course watersheds and for that matter hydrologic data from golf course watersheds is limited. Rainfall-runoff data from two golf courses, Morris Williams Municipal Golf Course (MWMGC) located in a semi-arid climate in TX and Northland Country Club located in a cool-humid climate in MN, were collected for a 5-yr period. One hundred twenty-seven events on MWMGC and 86 events on NCC were used to determine CNs. The measured CNs, for normal antecedent moisture (AMC II) conditions were determined to be 63.4 at MWMGC and 78.2 at NCC. Each of the four methods used to calculate CN from the measured data produced CNs that were consistent for each site (standard deviation at MWMCG was 0.7 while standard deviation at NCC was 1.6). Hydrologic soil group, local climate that affects evapotranspiration (ET) and thus antecedent soil moisture, and site characteristics, specifically slope, drainage density, and connectivity appear to have the most impact on the establishment of CNs for these two golf courses. The findings of this study indicate the importance of understanding local climate and site characteristics that influence hydrology when determining CNs. The CNs developed for these courses provide partial confirmation to CNs previously suggested for plot scale turfgrass systems but more importantly highlight the significance of having localized measured data. The results from this study suggests that determination of CNs for golf course watersheds should not be based on traditional sources that rely solely on using hydrologic soil classifications and landuse or vegetative cover type.