February 3, 2022 at 11:42 a.m.
Lund presents 2021 Great Lakes Stream Crossing Inventory results for Oneida County
Lund presents 2021 Great Lakes Stream Crossing Inventory results for Oneida County
By Beckie Gaskill-bjoki@lakelandtimes.com
This was the second year of the Inventory. In 2020, 105 stream crossings were surveyed. These were in the towns of Lynne, Minocqua and Woodruff. This year, 92 stream crossings were surveyed. The foci for 2021 were the towns of Crescent, Enterprise, Monico, Pelican, Piehl and Schoepke. Lund said the hope for 2022 is to focus on culverts and stream crossings in the towns of Cassian, Newbold, Nokomis, Pine Lake, Sugar Camp, Three Lakes and Woodboro.
Two of this year's crossings were listed as crossings of special concern, one of which was in Stella and the other in Cassian. These two added to the initial 90 surveys that would be completed from June to August of 2021 due to their condition. Of the crossings surveyed, five showed severe deterioration and 16 more showed major deterioration. Thirteen were listed as "not new" but in "good condition" and 18 as in "good condition." Seventeen showed "moderate deterioration" with another 18 "moderate to major deterioration."
Culverts can be an issue if they are undersized, perched, physically crushed or in poor repair or if they become plugged with debris. Many aquatic species use culverts as a passage from one place to another to complete their life cycles. Culverts that impede passability by aquatic life, then, create ecological issues that need to be addressed. Some culverts can even cause dangerous conditions for humans. Culverts that are deteriorating or in poor repair can lead to flooding and erosion issues. Erosion can change oxygen levels, affect fish feeding, increase water temperature, fill in spawning areas and smother aquatic plants, Lund said in her presentation.
The amount of erosion at the sites surveyed was measured to evaluate the extent to which it was causing an issue. This was done using the Universal Soil Loss Equation (USLE) from the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS).
Lund stated the effects of all culverts in a watershed are cumulative, with each adding to the overall picture of watershed health. For that reason, completing surveys of all stream crossings in the county is important to see the full picture. The optimal goal, she said would be to maximize connectivity on a basin scale while minimizing costs. Budgets for municipalities in the county are always tight and often finding money to put in a culvert, let alone a large-sized structure, can be difficult. This survey, however, would point the county in a direction to utilize cost-share money to repair or replace those culverts exhibiting the most dire need. From there, the county could move down the list to stream crossings that need work but may still afford passage for aquatic life at most flow stages.
"Data from on-the-ground surveys, coupled with improved communication between conservation and infrastructure is essential," Lund said in her recent presentation.
The assessments she completed looked at not just erosion issues but culvert size, structural integrity of the culvert itself and whether the culvert was a barrier to fish passage. A further distinction was made between culverts that were a barrier to passage at most flow levels, at high flow levels and those that were a 100% barrier.
Lund then laid out results on a town-by-town basis. The first of those was the Town of Crescent, where seven sites were surveyed. Of those 14.29% were not a barrier at all, but the same percentage posed 100% barriers to passage. Over 28% of culverts were a barrier most of the time and just under 43% posed a barrier at high flows.
Twenty-five sites were surveyed in the Town of Enterprise. Almost a third, 30.77%, of culverts were not a barrier to passage while the same amount were a barrier at high flows. Fewer culverts, 15.38%, were a barrier 100% of the time and 23.08% were a barrier at most flow levels.
Of the eight sites surveyed in the Town of Monico, 62.5% were a barrier to passage at most flows. One quarter were not a barrier at all. At high flows, 12.5% of culverts surveyed proved to be a barrier to fish passage. Four were put into the category of exhibiting major deterioration and two more were moderately to majorly deteriorated.
The Town of Pelican had 25 sites surveyed. Forty percent of those culverts were a barrier at high flow. Those listed as a barrier at most flows were 16% of the sites surveyed with the same number proving to not be a barrier to fish passage at all. However, 20% were a barrier at all times.
In the Town of Piehl, eight culvert sites were surveyed. Four, or 50% of those were a barrier at high flows. At most flows 25% were a barrier and 25% were not assessed due to bermed or gated roads making the site inaccessible.
The last town Lund spoke about in her recent presentation was the Town of Schoepke. This town had 16 sites surveyed. One quarter of those were a barrier to fish passage at high flow levels. At most flow levels, 12.5% of sites surveyed were a barrier to fish passage and 18.75% were a barrier 100% of the time. The news was better, though, for those that did not create a barrier at all, with 43.75% of Schoepke's culverts in that category.
From there, Lund created a list of priority crossings due to passability issues. This looked at whether or not the structure length was over 30 feet, whether the water was at least 6 inches deep, if the water velocity exceeded three feet-per-second, whether the culvert was perched (with the down stream end above the water level) and whether there was a scour pool. The scour pool, she said, was a function of the velocity of water below the outlet. Those culverts and crossings that did not meet several of the criteria were placed on a priority list for passability.
Looking at condition issues, she said, other conditions were taken into account. The percentage of the culvert that was plugged or crushed was taken into account as was whether the structure was rusted through. Each was also given a value for overall condition. Those that fell into the conditions of severe or major deterioration were given priority designations.
With all of this information in the database, Lund said, the county is in a much better position to help towns, for instance, who are looking to rectify culvert issues on town roads. Being proactive and getting information out to townships before the culverts fail completely or cause even larger issues than they are causing now will allow the county to work with towns to secure cost share funding to repair or replace problem culverts, thus lightening the financial load on a town while still allowing a properly sized culvert to be placed, creating environmental benefits as well. The full results will be available on the Oneida County Land and Water website oclw.org.
Beckie Gaskill may be reached via email at bgaskill@lakelandtimes.com.
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