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f NVf NTD�Y 'F XTf NT The MCSWCD has been proactive and successful in bringing
<br /> together both parties—developers and local government entitie�—
<br /> CrOpland (Continued) in discussions addressing the how's, why's, and the benefits of
<br /> sediment and erosion control ordinances.
<br /> calculations using USLE estimated 3 tons of soil loss compared to
<br /> 2 tons of soil loss using RUSLE. For comparison purposes, the
<br /> 1995 study, which considered soil loss on 7 tracts using the USLE Streambank areas
<br /> format was compared to the 1999 study which used the RUSLE Based on the 1995 study,streambank segments within four primary
<br /> format. There were no significant soil loss differences between sampling units (PSU's) were inventoried for streambank erosion
<br /> the study years; however, ephemeral erosion from concentrated concerns. These PSU's were inventoried again in 1999 to
<br /> flow areas was estimated in the 1995 study, but was actually determine if erosion from streambank sources had drastically
<br /> measured in the field for the 1999 study. When calculating soil increased. On-site visits indicated that streambank erosion did
<br /> deposition, a SDR (sediment delivery ratio) of.25 was employed not drastically increase over the five-year period. However,
<br /> for sheet and rill erosion to estimate soil sediment entering Lake exisiting segments experiencing streambank erosion have not been
<br /> Decatur. treated and continue to contribute to water quantity concerns of
<br /> ��- Lake Decatur.
<br /> j� :_'-�"�"�<�.;µ�`" vt.;. •._:_ .�,,. w- ` —
<br /> Nofe:When calculating soil losses caused by streambank erosion,
<br /> _ Lateral Recession Rates are measured in the field. Shown here is
<br /> a photograph that represents a situation categorized as "Severe
<br /> `��: streambank erosion." Because of the expense controlling erosion
<br /> s ��� g on streambanks, only a"severe° rate is justified to fund measures
<br /> , ,=: , a , : . r = for streambank control.
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<br /> �.,it ...;.�'Y�9 � .:1, y9y�.d 'L ..$4 a.� �?Z'�.. �yl�r �_ �� � �.` � '__j � •
<br /> a
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<br /> ��. ' t�I rc�'��, ! t ��a����, "4+ � � ��, �' � �,�e�� �� .i ��'`-'- � y.���� � � �:,4''' i
<br /> t�� 1 �I�i � Y�/.. .J'; 4�4V F� :.\ L f�' <J'1�ty' � '4'�'S'�'-_ ".�'�.�I" .� 6r .
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<br /> Appendix#1 also contains a listing of BMP's highlighted in green, . s� _ •�� �° �� � _ =.'
<br /> which when implemented, will control ephemeral/gully erosion � �:� ''� �;✓ �` ��� �
<br /> concerns in PHEL/HEL mapping units. These structural measures -�Y ��� � - � ��<"` _ ;'� q
<br /> are needed to compliment the ongoing management practices ��'=� _ �_ - -' � ,;;��' `��i
<br /> currently used by producers. Sheet/rill erosion losses in the � ` � _'"� �,`� _
<br /> watershed are currently below "T" (allowable soil loss) because �` � � � `� >`
<br /> q � �,
<br /> of the many conservation tillage techniques used throughout the � ,�� , _ =....� �' -�
<br /> region. However,in orderfor a true resource management system Severe: In order to qua/ify as"severe,"the streambank must be bare, with
<br /> to be implemented, both managementtechniques and structural noticeab/evegetativeoverhang. Manytreerootsareexposedandsome
<br /> measures must be installed and maintained as a comprehensive fa/len trees are present. Slumping orrotational slips are a/so present.
<br /> system that addresses soil erosion control. Both aspects are Some changes in cultura/features.such as missing fence posts and
<br /> realignment of roads.may a/so be characteristic.
<br /> needed to improve the water quantity and water quality concerns
<br /> of Lake Decatur. Since 1995, the MCSWCD has employed the latest technology in
<br /> order to control streambank erosion. They have installed
<br /> Urban land longitudinal peak stone and bendway weirs, as indicated in the
<br /> The Lake Decatur watershed is predominately agricultural in Photograph.
<br /> nature, however, much of the land is suitable for conversion to
<br /> urban/community and residential development. Although present r�A } r� � � _, t.� r��r - ��
<br /> urban development initiatives in the watershed have been �, R'��. � f ' s" � ,. � �-�� �
<br /> � ��P.n, � '�' �, h1 f = �,--��`'_.`_-'"� �.
<br /> stabilized,surroundin g watersheds are experiencing erosion from ��� . '��,�yg,, t4 a�' � �. _ �: T�
<br /> neighboring construction siteswhich are negatively impacting Lake �k,��'�S ��� �,��� n��� �.� ,;� «;. -���
<br /> �-���
<br /> Decatur.Current efforts to assistthe City and County governments ``'�,���, t �, �'� ����� ���, , � J,�� . ��- -:�
<br /> with urban erosion and sediment control issues include: ' '�` �*'�� #��� � ' "
<br /> s^����,��•,� ,` � :
<br /> • Hosting workshops to develop a unified sediment erosion � "` '� �- `��`� 1 ''�1��►'� ' � � �
<br /> control ordinance =f4�� 7 '�� � ' ��� °,��
<br /> �:� - �. 9���
<br /> ti. -� v- _ � , ��°�:
<br /> • Working with progressive contractors on planning & � � �S Y �=` �-
<br /> implementing sediment and erosion control plans and �`��=�` _ - �� '
<br /> showcasing them on watershed tours � "`_ ` � � {' ,�'� �. � -�,���� -� `
<br /> • Educating developers on the BMP's, standards, and �" � � � � �-���
<br /> -�:. ' .�: �
<br /> specifications needed for successful erosion control �,�� _ _. *- _�a� �` -� ` ` "- ;
<br /> measures such as those featured in the NRCS Urban �"'�.����' � �t � - � r 3'' �.-
<br /> Manual ����� `��:� "" ` �- ���, ,� -
<br /> � '�:�
<br /> 2 � � ; - . _ �,�4
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