Illinois Environmental Protection Agency Crooked Creek Watershed TMDL Implementation Plan
Draft 55
The NRCS provides additional information on drainage management at:
http://efotg.nrcs.usda.gov/references/public/IL/554.pdf.
5.9.1 Effectiveness
Use of control structures on conventional tile drain systems in the coastal plains has resulted in reductions
of total phosphorus loading of 35 percent (Gilliam et al., 1997). Researchers at the University of Illinois
also report reductions in phosphorus loading with tile drainage control structures. Concentrations of
phosphate were reduced by 82 percent, although total phosphorus reductions were not quantified in this
study (Cooke, 2005). Going from a surface draining system to a tile drain system with outlet control
reduces phosphorus loading by 65 percent (Gilliam et al., 1997).
Storage of tiled drained water for later use via subsurface irrigation has shown decreases in dissolved
phosphorus loading of approximately 50 percent (Tan et al., 2003). However, accumulated salts in reuse
water may eventually exceed plant tolerance and result in reduced crop yields. Mixing stored drain water
with fresh water or alternating irrigation with natural precipitation events will reduce the negative impacts
of reuse. Salinity thresholds for each crop should be considered and compared to irrigation water
concentrations.
5.9.2 Costs
The Champaign County Soil and Water Conservation District currently offers tile mapping services for
approximately $2.25/ac using color infrared photography to assist farmers in identifying the exact
location of their tile drain lines. Similar services are likely available through local vendors in the Crooked
Creek watershed. Cooke (2005) estimates that the cost of retrofitting tile drain systems with outlet
control structures ranges from $20 to $40 per acre. Construction of new tile drain systems with outlet
control is approximately $75/ac. The yield increases associated with installation of tile drain systems are
expected to offset the cost of installation (Cooke, 2005). It is assumed that outlet control structures have a
system life of 30 years. Cost assumptions for retrofitting and installation of new tile drain systems with
outlet control devices are summarized in Table 5-15.
Table 5-15. Costs Calculations for Outlet Control Devices on Tile Drain Systems.
Item Costs to Retrofit Existing Systems Costs to Install a New System
Mapping Costs per Acre $2.25 $0
Construction Costs $20 to $40/ac $75/ac
System Life (years) 30 30
Average Annual Costs $0.75 to $1.50/ac treated $2.50/ac treated
5.10 Proper Manure Handling, Collection, and Disposal
Animal operations are typically either pasture-based or confined, or sometimes a combination of the two.
The operation type dictates the practices needed to manage manure from the facility. A pasture or open
lot system with a relatively low density of animals (1 to 2 head of cattle per acre (USEPA, 2002a)) may
not produce manure in quantities that require management for the protection of water quality. If excess
manure is produced, then the manure will typically be scraped with a tractor to a storage bin constructed
on a concrete surface. Stored manure can then be land applied when the ground is not frozen and
precipitation forecasts are low. Rainfall runoff should be diverted around the storage facility with berms
or grassed waterways. Runoff from the feedlot area is considered contaminated and is typically treated in
a lagoon.
