was 7 , 4 9 0
l o n g and r e q u i r e d 441,237 t o n s
was
l o n g and r e q u i r e d
tons
s t o n e . Both j e t t i e s had a c r e s t e l e v a t i o n of +15
m l l w , c r e s t w i d t h s of
to
t o 20 f t , and s i d e s l o p e s of
96. The n o r t h j e t t y was r e h a b i l i t a t e d d u r i n g 1957 t o 1958.
A 600- ft
e x t e n s i o n t o t h e n o r t h j e t t y was a u t h o r i z e d i n 1958, b u t it was deferred
u n t i l , i n t h e o p i n i o n of t h e D i s t r i c t E n g i n e e r , t h e e x t e n s i o n was a d v i s a b l e .
I n 1981, t h e Design Memorandum was p r e p a r e d f o r e x t e n d i n g t h e n o r t h j e t t y by
2,000 f t , i n c l u d i n g t h e 6 0 0 - f t e x t e n s i o n a u t h o r i z e d i n 1958, a n d e x t e n d i n g t h e
s o u t h j e t t y by 2,500 f t . The e x t e n s i o n s have n o t been c o n s t r u c t e d . A chro-
n o l o g y of e v e n t s related t o t h e development and r e p a i r of t h e j e t t y s t r u c t u r e s
T i l l a m o o k Bay, Oregon
97. T i l l a m o o k Bay is located on t h e P a c i f i c coast of Oregon, a b o u t
47 miles s o u t h of the Columbia R i v e r . The p r o j e c t i n c l u d e s two rubble-mound
j e t t i e s p r o t e c t i n g t h e e n t r a n c e t o t h e bay and a d i k e r e p a i r i n g a breach i n a
s p i t on t h e w e s t e r l y s i d e of t h e bay.
98. The 5 , 7 0 0 - f t - l o n g n o r t h j e t t y was a u t h o r i z e d i n 1912 and con-
s t r u c t e d d u r i n g 1912 t o 1914 t o 5,400
The j e t t y was r e c o n s t r u c t e d d u r i n g
t o 1933, i n c l u d i n g a 300-ft e x t e n s i o n , t o t h e f u l l a u t h o r i z e d l e n g t h .
The j e t t y was r e h a b i l i t a t e d d u r i n g 1963 t o 1965 t o r e p a i r damage c a u s e d by
u n d e r m i n i n g of t h e s t r u c t u r e . The j e t t y head has r e c e i v e d some damage from
extreme wave c o n d i t i o n s , b u t no improvements are p l a n n e d a t t h i s time.
The 8 , 0 0 0 - f t s o u t h j e t t y was a u t h o r i z e d i n 1965, a n d c o n s t r u c t i o n
of t h e f i r s t 5,000 f t was i n i t i a t e d i n 1969. Deep s c o u r i n g of t h e bottom
ahead of t h e j e t t y caused o v e r r u n s , and c o n s t r u c t i o n was h a l t e d a t a l e n g t h of
i n 1971. The j e t t y was e x t e n d e d 2,830 f t d u r i n g 1972 t o
and
t h e d i s t a n c e between t h e j e t t i e s was decreased from 1 , 4 0 0 t o 1,200 f t . The
j e t t y was e x t e n d e d t o t h e f u l l a u t h o r i z e d l e n g t h of 8,000 f t d u r i n g 1978 t o
The f i n a l l e g of the j e t t y has shown some s u b s i d e n c e , b u t no r e p a i r
work is p l a n n e d a t t h i s time. A c h r o n o l o g y of e v e n t s r e l a t e d t o t h e d e v e l o p -
Umpqua R i v e r , Oregon
The Umpqua R i v e r flows i n t o t h e Pacific Ocean on t h e Oregon coast
miles s o u t h of t h e Columbia R i v e r . The town o f Reedsport, Oregon,
is l o c a t e d 12 miles u p s t r e a m from t h e mouth o f t h e r i v e r .
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