How many HUC example codes one have 1 level?
Name Level Digits Average size (square miles) Number of HUs (approximate) Example name Example code (HUC)
Hydrological code
16087261
text real real text real text real
2-16087261-2
United States
United States
Region 1 2 177,560 21 Pacific Northwest 17
Subregion 2 4 16,800 222 Lower Snake 1706
Basin 3 6 10,596 370 Lower Snake 170601
Subbasin 4 8 700 2,200 Imnaha River 17060102
Watershed 5 10 227 (40,000–250,000 acres) 22,000 Upper Imnaha River 1706010201
Subwatershed 6 12 40 (10,000–40,000 acres) 160,000 South Fork Imnaha River 170601020101
SELECT COUNT Example code (HUC) FROM table WHERE Level = 1
1