The mound side slope should not be steeper than 3:1 (run:rise) for safe mowing. Therefore, the mound sand footprint will be extended in all directions outside the distribution area. The upslope width intersects the site slope and an upslope width correction factor is used for the width adjustment. The upslope width correction factor can be calculated as 1/[1+(Mound side slope factor, or run)*(Site slope)]. Upslope width correction factors are provided in Table 3 for a 3:1 mound side slope for various site slopes.
| Table 3. Upslope Width Correction Factor for a 3:1 Mound Side Slope | |
|
| Site Slope (run/rise) | Correction Factor | |
|---|---|---|
| 1 | 0.97 | |
| 2 | 0.94 | |
| 3 | 0.92 | |
| 4 | 0.89 | |
| 5 | 0.87 | |
| 6 | 0.85 | |
| 7 | 0.83 | |
| 8 | 0.81 | |
| 9 | 0.79 | |
| 10 | 0.77 | |
| 11 | 0.75 | |
| 12 | 0.73 | |
| 13 | 0.72 | |
| 14 | 0.70 | |
| 15 | 0.69 | |
Upslope Width = (Mound side slope factor, or run)*(Mound sand fill upslope depth + Aggregate depth + Distribution protection depth)*(Upslope correction factor)
Upslope Width:
The recommended mound side slope is 3:1 in this design example and the corresponding upslope correction factor is 0.73.
| Upslope Width | = (Mound side slope factor)*(Mound sand fill upslope depth + Aggregate depth + Distribution protection depth) *(Upslope correction factor) |
| = (3)*(22 inches + 9 inches + 6 inches)*(0.73) | |
| = 81 inches | |
| = 6.75 ft |