Wind farm construction does not fall under the Wisconsin law requiring or allowing agricultural impact statements. However, wind farms can remove farmland from production, impede normal farm operations, and reduce soil productivity by mixing layers, compacting soils, and damaging drainage systems.
In general, developers should site wind turbines and access roads so that they have the least effect on farm efficiency, while maintaining the shortest distance between structures. Measures that may reduce the impact of wind farms on farmland include the following:
- Site wind turbines on farmland with lower soil productivity.
- Avoid areas of intense vegetable production that require aerial pesticide application.
- Site wind turbines and access roads on field edges as much as possible, to avoid creating small, irregularly shaped fields that are less efficient to farm.
- Site wind turbines on low-quality woodland rather than productive farmland.
- Site access roads along high ground or ridges to minimize the amount of cut and fill, and to alleviate drainage and erosion problems.
- Avoid surface and subsurface drainage systems. If that is not possible, find out where existing drainage improvements are before you begin construction, so that you can repair or replace them after finishing construction.
- Site parking areas, construction staging areas, and other temporary and permanent support facilities outside of active agricultural fields where possible.
- To avoid mixing soil layers, remove topsoil before excavating, grading and trenching. Segregate topsoil from other excavated material. If buried circuits are trenched or plowed in, no topsoil stripping is required.
- Store and stabilize topsoil so it does not erode or mix with subsoil or underlying soils, and in a way that does not impede field drainage.
- Before replacing topsoil, plow or deep-rip soil 18 inches deep in areas compacted by construction. Use a soil penetrometer to check success in loosening compacted soil.
- After plowing and before replacing topsoil, remove rocks that are bigger than three inches in diameter.
- Remove excess subsoil and rock from the site, unless the landowner directs otherwise.
- Make access roads through farmland only wide enough to accommodate construction traffic.
- Confine vehicle traffic and parking to access roads, designated work areas at the tower sites, and designated parking and material laydown areas.
- Build adequate fencing to keep livestock away from the construction area.
- Make the final access road level or nearly level with the surrounding field, so farm equipment can cross the road easily.
- Bury cables in farmland at least four feet deep. If bedrock prevents this, bury cables at least two feet deep and below the top of the bedrock.
- Install culverts and water bars where needed to maintain natural drainage flows.
- Remove excess concrete from the site. Do not bury it or leave it on the surface of active farmland.
- After construction, remove leftover metal objects, such as wire, bolts, etc.