Waterwise Wednesday: Rain Harvesting Romans

Image may contain: sky, grass, plant, cloud, mountain, outdoor and natureRecent research suggests rain harvesting may have provided the 800 Roman soliders manning Hadrian’s Fort with 10 liters (2.62 gallons) of drinking water per per capita per day during their deployment.

Evidence at Hadrian’s Fort, a strategic Roman outpost along Hadrian’s Wall in northern England, indicates building rooftops were constructed to capture rainfall. The runoff collected in stone-lined tanks, two to six tanks per key building, capable of holding 2 cubic meters (about 528 gallons) of water each.

It’s an amazing feat of foresight, considering Hadrian’s Fort has no internal springs or wells, access to springs or waterways in the region, and an aqueduct supply would have been extremely impractical.

Photo by David Ross
Hadrian’s Wall at Steel Rigg
Twice Brewed, Northumberland, England

Waterwise Wednesday: Only Rain in the Drain, Please

Stormwater is not treated before it flows into the North Platte River, so contaminants that enter the storm sewer system can also contaminate the river.

According to regulation, anything other than rain or snowmelt in the storm sewer is an illicit discharge. However, clean water discharges to the gutter – like pumped groundwater, air conditioning condensation, or irrigation water/lawn watering – are typically excused.

If you see or find evidence of substances other than rain or snowmelt in the gutter or near a storm drain please call the stormwater department 630-8011. If the spill is over 25 gallons or you know the substance is hazardous, please call 911.

Waterwise Wednesday: Snow Science

Cloudy winter days make the snow melt faster, says a study from the University of Utah. Snow is designed to stay cold in three ways: by deflecting the sun’s heat with it’s bright white color and crystalline structure, the bright white reflecting heat back at night, and sublimation, evaporating from snow to vapor, similar to the way sweat evaporates from our skin to keep us cool.

Cloudy humid days, however prevents snow from deflecting, reflecting and sublimating warming the snow. That is why a few humid days with temperatures hovering around the freezing point create large melt events and even minor flooding.

Do your own experiment by watching snow that remains in shadows even on warm sunny days. Then watch what happens to that same snow during gray days and nights — quickly, though, before it’s all gone.

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