A bill tightening state limits on groundwater withdrawals died on the house floor on Monday.
House Bill 1103 intended to help prevent withdrawing more water from aquifers, particularly in the Black Hills, than can be recharged naturally each year.
The prime sponsor of the bill was Representative Scott Odenbach. He said the bill addressed concerns that water demand in western South Dakota may be outpacing supply.
The bill worked by removing the Greenhorn Formation exemption from the state's water rights laws. The exception allows the state to issue permits to water distribution systems, such as municipalities, rural water systems and suburban housing developments, to withdraw from groundwater sources older than or stratigraphically lower than the Greenhorn Formation in excess of annual recharge rates.
The Greenhorn Formation is a Cretaceous-aged sedimentary formation. Major aquifers in the Black Hills that supply drinking water like the Madison are older and stratigraphically lower than the Greenhorn Formation. Odenbach said the bill would prompt DANR to install more monitoring wells as needed to better measure the recharge rates of aquifers below the Greenhorn Formation.
"I think what we need to do is take out that Greenhorn exception, decide this is a priority as a state as a core function of government to say 'Hey, lets make the investment if we need it in ensuring we have enough monitoring wells and that if people are going to want to come in and add new uses of water, we know what we've got going on down there,'" said Odenbach on Monday.
According to Odenbach, the bill would have aligned the law with how the Department of Agriculture and Natural Resources (DANR) already operates. He said DANR has factored in recharge rates for all nineteen of the water permits issued in the state since 2023 that qualified for the Greenhorn Formation exception.
"DANR went ahead and did a recharge withdrawal balance study anyway for all of them," said Odenbach. "And they ended up issuing all of the permits. So they're basically already doing this now [...] So, it's not like it's a Draconian, red line thing."
There are aquifers outside of the Black Hills region that are older and stratigraphically lower than the Greenhorn Foundation, such as the Dakota Aquifer. A single map showing all of South Dakota’s aquifers does not exist, according to a publication by the South Dakota Geological Survey.
Opponents of the bill cited concerns about the cost of installing additional monitoring wells, impacts to public water supplies, scientific uncertainty around recharge rates and potential increases to water bills.
The bill was amended to go into effect in 2027, giving officials extra time to prepare for its implementation. The House of Representatives voted 16-46 against the bill.