Two massive earthen dams on the southwest side of Columbia hold the waters of Hulen Lake.
These structures — built more than 70 years ago in 1948 and modified in 1989 — are hundreds of feet long and 50 feet high.
What makes them unique compared to most dams in Boone County is the safety measures they undergo.
The height of Hulen Lake’s dams means that they are inspected every two years by state engineers as part of the Dam and Reservoir Safety Program, which is the Department of Natural Resources (DNR) initiative to ensure the safety of downstream residents against dam failures.
Lakeshore Estates, which owns the dams, is also required to compile an emergency action plan (EAP).
The Hulen Lake dams — the highest in the city — are two of only 14 dams in Boone County that have these plans.
An EAP is a formal document that identifies potential emergency conditions at a dam and specifies actions to reduce property damage and loss of life.
“The EAP includes actions the dam owner should take to mitigate problems at the dam and issue warnings to responsible emergency management authorities,” Adoratia Purdy, public affairs specialist with U.S. Army Corps of Engineers’ Dam & Levee Safety wing, explained in an email.
But the most recent data — compiled by the DNR and published Nov. 30 by the U.S. Army Corps of Engineers — show that most of the 108 private dams in Boone County are not required to undergo the safety scrutiny given to the Hulen Lake dams.
That’s despite the fact that dam failure is listed as a threat in the Boone County Hazard Mitigation Plan, albeit a low threat.
One of the Boone County Emergency Management Department’s mitigation goals is to better understand the unregulated dams in the county.
But that is difficult to do, as county officials acknowledge that even they don’t have a full accounting of the number of private dams in the community.
Hannah Wichern, a mitigation and recovery specialist in the department, says it is possible there are more dams than government officials have on record. She is working to compile a more precise inventory of Boone County dams and their owners.
“Our office is very open to working with private dam owners, and we would love to establish those relationships and provide the tools that they need to create emergency action plans,” Wichern said.
The need for the attention of county emergency officials becomes obvious when one realizes that the majority of dams in Boone County — 96 out of 126 — are privately owned and therefore fall outside of state and federal safety regulations.
That calls into question their potential risk — and no one really knows what that risk might be.
What is known is that the 2020 National Inventory of Dams classifies 39 of those privately owned Boone County dams as “high hazard.” Over a thousand privately owned dams in Missouri are classified at that level.
The hazard classification reflects the potential for damage to the population and development downstream from a dam.
When a dam has a classification of “high hazard” potential, any probable failure or mis-operation of the dam could result in likely damage to surrounding land and property and even lead to loss of human life, states the National Inventory of Dams (NID).
NID is the federally authorized database published and maintained by the U.S. Army Corps of Engineers. It is charged with documenting all the dams in the United States and territories, containing vital information and regulatory facts about each dam.
In Boone County, privately owned dams range from 13 to 60 feet high. Many of the dams were built in the 1960s and 1970s — the oldest, Wabash Lake Dam — was completed in 1890.
All but two of the dams in the county are earthen, meaning they’re constructed of dirt and other natural materials. The dams serve a variety of purposes, but 46% are used for recreation.
The 1972 National Dams Inspection Act — which led to the formation of NID — extends to every dam in the United States. The act calls for dams to be inspected on two-, three- and five-year intervals based on the downstream environmental hazard classification.
However, that critical dam inspection requirement does not extend to privately owned dams that are less than 35 feet in height, as are the majority of the dams found in Boone County.
While NID urges private owners to get dams on their properties inspected, it is not required by law.
Statewide, 67% of dams have no inspection listed in the national inventory — 92 of Boone County’s dams are missing inspections.
Boone County’s Hazard Mitigation Plan states that the current lack of required dam inspections increases the likelihood of severe conditions being ignored by owners.
“We don’t have an enforcement power; we just have the power of suggestion.”Chris Kelley, director of Boone County Emergency Management
It’s easy to see why, when there is such a large number of existing unregulated, privately owned dams that have a high hazard classification on the city, county and state level.
With no legal hammer to require action by private land owners, emergency officials are toothless in mitigating potential problems.
“We don’t have an enforcement power; we just have the power of suggestion,” said Chris Kelley, director of Boone County Emergency Management. “We can suggest, and we hope that folks will take our information, but that’s all we can do at this point.”
The county has been making efforts to reach out to owners of unregulated dams to encourage safety preparations.
However, it can be hard to locate and contact landowners, some of whom were put in the database decades ago. The Missourian’s efforts to find and speak with private dam owners were unsuccessful. County officials experience similar challenges.
In 2016 the Boone County Emergency Management Department worked with DNR to offer a safety class for private dam owners to, among other things, craft emergency action plans. No one took them up on the offer.
A lot of the private dams in the state were inspected when they were added to the NID in the 1970s and 1980s for the first time. However, that is the last inspection officials have on record for most of them.
But Boone County’s Hazard Mitigation plan urges caution in assuming private dam classifications are still accurate.
“It is very probable that, for most of the nonregulated dams, the classification does not take into account almost 30 years of development and change in Boone County,” the report says.
Any power local officials have regarding dams is narrow and does not address existing infrastructure. If a new dam, over 25 feet high, is to be built within a subdivision — county regulations apply. However, if a new development was proposed downstream from an existing dam in Boone County, the regulations don’t apply.
While Wichern works to connect with private dam owners, she accepts the county’s lack of regulatory authority.
“I think that the current processes are sufficient. But that’s not to say that we maybe haven’t taken into account the growing threat of climate change and how things quickly can change in that aspect,” Wichern said.
The Hazard Mitigation Plan also echoes the impending threat of climate change for dams and points to how inspections could help.
“Since precipitation is predicted to increase in the future with potential for more vigorous rainfall events, this creates an elevated risk of flooding and pressure on dams and spillways to handle the extra water amounts,” the report says.
“This elevated pressure brings about the importance for regular inspections and maintenance, as well as the need for engineering with higher flood levels in mind,” it says.
"Many of the privately owned dams were built in the 1930s and 1940s, and some are nearing the end of their lifespan.”Marisa Frazier, Sierra Club Conservation Program Coordinator
The Missouri Chapter of the Sierra Club has environmental and safety concerns about the area’s unregulated dams.
“Sometimes dams provide a false sense of security, encouraging suburban development that encroaches on the stream because they have the expectation that the dam will hold back the waters that would otherwise end up in their basement,” said Marisa Frazier, Sierra Club Conservation Program Coordinator.
“Building near waterways removes important vegetation that controls erosion and protects water quality,” she says.
Frazier added that the Sierra Club would like local government to have more authority over this type of privately owned infrastructure.
“If there are dams, they should be properly maintained. Many of the privately owned dams were built in the 1930s and 1940s, and some are nearing the end of their lifespan,” said Frazier. “Safe construction of dams should be a priority.”
Boone County Resource Management Director Bill Florea has been working for the county for almost 25 years. He says private dam owners have an interest in ensuring the infrastructure is kept up. Contributing to the lack of attention this issue gets from the county is the fact that there haven’t been many dam-related catastrophes, he says.
The last known dam-related mishap in the vicinity was when the Hominy Branch dam failed in 2008. However, there was little damage, perhaps adding to a false sense of security.
Florea says that during his time with the county there haven’t been many issues with dams.
In 2009, after emergency workers in Cole County worked to relieve pressure on an unregulated earthen dam to prevent a breach, Florea said there was some talk about whether Boone County should reconsider dam regulations. Nothing materialized.
But Florea said he believes it might be worth considering enacting regulations for when development is proposed downstream from an existing dam.
“My only concern is development that might be downstream from a private dam and to make sure that that’s safe,” said Florea. “So that would be the only area I think that we should probably consider addressing in the future.”
Improvements or modifications to dams can cost tens of thousands of dollars. According to Purdy, the federal government provides some grant funding through FEMA and USACE to rehabilitate dams. Florea said providing financial support to private dam owners for repairs is not something the county is in a fiscal position to do.
The lack of local control over dam infrastructure likely won’t be addressed soon. Kelley says any change in county dam regulation would need to come from the citizens of Boone County.
“The citizens of those areas would have to come to elected officials and push for those sorts of legislation to regulate those at a county or city level,” said Kelley.
