Dwight,

The actual way to determine gradient would be to have three wells set in that saturated gravel layer and survey the elevation of the water level in each well. Three points define a plane (the groundwater surface)with a slope in one direction.

You can ballpark it by knowing that the Rock River is draining your property, therefore the predominant flow should be toward the river (east)with a downstream trend (eastsoutheast). Topography also has an influence because it creates head differences. If you have any high (or low) areas nearby, they may deflect flows from the expected direction. The north and west sides opening first is consistent with drainage to the southeast since upgradient is northwest. Remember that groundwater temperatures are near 50 degrees F and will definitely melt ice if there is good flow. The north side also has southern exposure and warms quickly so there may be two things working here.

We have been above 40 since Christmas. My property is low so has received quite a bit of runoff and groundwater recharge (pond levels are 4-feet higher than September and still rising). The Lake definitely moderates our climate, the thin strip along Lake Michgan is listed as USDA Zone 6b (-5F) which is equivalent to Kentucky.

We had frost in late November and early December but never had good ice due to the groundwater discharge. Water has been slowly seeping onto the edges of the ice for three months.