The sediment input to the river could be reduced in the future by 

 wide adoption of soil conservation practices in the Illinois basin, 

 including such new practices as no-till farming, where row crops are 

 planted directly in stubble or some other ground cover, without greatly 

 disturbing the soil. The ground cover breaks the impact of raindrops, 

 and holds water, soil, and nutrients, rather than allowing all three to 

 run rapidly into tributary streams, thence into the river. 



Before no-tillage or minimum tillage is practiced on a wide scale, 

 the total energy requirements (including the energy for the manufacture 

 of agricultural chemicals) of various alternative farming methods need 

 to be determined, and the environmental impact of the herbicides that 

 must be used with present no-till farming methods needs to be assessed. 

 In the future, it may be possible to reduce the amount of herbicide used 

 in no-till farming by choosing the proper sequence of crops and by 

 breeding varieties of row crops that can compete with weed species. No- 

 till farming does reduce the energy required by farm machinery, since 

 there is little or no plowing, harrowing, or cultivating. No-till 

 farming also enables farmers to get on their land earlier in the spring 

 for planting, because sod is not as slippery or soft as bare ground. 

 Proposed increase in diversion 



The city of Chicago and lakefront residents whose property has been 

 damaged as a result of recent high-water levels in Lake Michigan have 

 requested an increased diversion of Lake Michigan water into the 

 Illinois River. Since Lake Michigan water is good quality water, it 

 probably would improve the quality of the upper river by simple dilu- 

 tion, if diversion occurred during the summer months. 



Hovrever, increased diversion would probably raise water levels, 

 with some of the detrimental effects discussed earlier. In addition, 

 if ammonia removal is not achieved by the Chicago Metropolitan Sanitary 

 District, the effect of increased diversion would be to push this ox- 

 ygen- demanding waste further downstream before its oxygen demand could 

 be. satisfied. 



68 



