TH he ALUsDA BO Nes B.Urb LET UN 29 
n example of landscape archi- 
yre, and as a public park.” 
1g with the park Allerton gave 
ly 4000 acres of his farmland 
rovide a permanent income to 
for the park. 
Corps Finds a Damsite 
s with a number of America’s 
iral resources, this gift to the 
srations to come may not sur- 
. the present generation. The 
ry Corps of Engineers has pro- 
.d an Oakley Dam and Reser- 
project that would flood more 
1 1000 acres of Allerton Park. 
961 the Corps suggested a 49- 
high dam 12 miles downstream 
7 Allerton Park on the Sanga- 
1 River. Its main reservoir 
nservation” pool) would be 621 
above sea level and during 
1 periods would reach 645 feet 
ve sea level. The conservation 
1 would not inundate Allerton, 
the flood pool periodically 
ild cover about 700 acres of the 
k. The purposes of this dam 
e water supply for the nearby 
of Decatur, flood control, and 
‘eation. In 1962 Congress auth- 
ed the project. 
uring 1965 and 1966 the Corps 
ituted several changes. The 
1 was hiked to 60 feet—keep in - 
id that here on the Illinois prai- 
every foot added to the height 
he dam means another mile of 
ndated land behind the dam. 
2 conservation pool level was 
reased to 636 feet and the flood 
el to 654 feet. 
fhe Corps sought to raise the 
n to cover several mistakes 
de in the 1961 project proposal; 
ation was greater than what 
y had figured and the maximum 
flood on record was not the one 
whose statistics they had used 
initially. By adding a fourth pur- 
pose, low flow augmentation (sew- 
age dilution) for Decatur, these 
mistakes were covered up and the 
volume of water was increased 
enough to take care of the errors 
as well as the low flow. 
The increased volume of water 
would also take care of Allerton 
Park. Instead of a dam that would 
trespass on Allerton during flood 
conditions, the revised project pro- 
vided a dam that would per- 
manently inundate over 40 per 
cent of the park. 
In addition to the dam and reser- 
voir the Corps planned 100 miles 
of downstream channelization on 
the Sangamon River. The $18 mil- 
lion channel improvement would 
require that 2800 acres be cleared 
for flood releases from the Oakley 
project. Thus, a 100 foot wide spoil 
bank would dominate the cleared 
area for the entire 100 miles. 
Then, in March of 1969 the Corps 
reported, that to meet Illinois’ new 
water quality standards the pro- 
ject had to be enlarged again. The 
conservation pool was set at an 
elevation of 641 feet, 20 feet higher 
than what was authorized by Con- 
gress, and the flood pool at 656 
feet, 11 feet higher than originally 
planned. Allerton Park would be 
gradually split in two as the waters 
of the Sangamon spilled over the 
lowlands. Finally when the reser- 
voir filled, flooding 650 acres of the 
park, only the higher fragments of 
the park on either side of the for- 
mer river would be above water. 
Conservationists Mobilize 
In 1967, when the public learned 
that the revised Oakley project 
