Loading ...
Sorry, an error occurred while loading the content.

Big Tujunga Dam Sediment removal IS/MND

Expand Messages
  • Bud
    Write a letter to on the LACFCD Big Tujunga Sediment removal project IS/MND yet? Please do, ask them to release a small portion of the high quality sand being
    Message 1 of 2 , Jun 18, 2013
    • 0 Attachment
      Write a letter to on the LACFCD Big Tujunga Sediment removal project IS/MND yet? Please do, ask them to release a small portion of the high quality sand being removed from behind the dam into the river below the dam for the replenishment of Arroyo Toad habitat. We have until june 26th to submit comments. Also Supervisor Antonivitch office is a good place to call and email.

      website dpw.lacounty.gov/wrd/projects/BigTujunga/

      An MND can only be used (in place of an EIR) if all the projects resulting potentially significant effects are avoided or mitigated to below significance. This IS/MND ignores the project significant impact to Sunland's Arroyo Toad critical habitat (subunit 7a), Arroyo Toads are now extirpated here due to Big Tujunga Dam, the capture and removal of sediment sand and gravel and diversion from our riverbed, that directly caused the revocation of Arroyo Toad critical habitat protection in Sunland's portion of the Big Tujunga River Wash (subunit 7a)! This MND document don't adequately address the indisputably significant impact of the unnatural alteration of riverbed sediment deposition (known as the fluvial process), insisting on removal of all the sand, and releasing none downstream, has a significant impact on the recovery of the Arroyo Toad in Sunland. Lower reach of the river below the Dam was designated final protected critical habitat (subunit 7a) for the recovery of Arroyo Toads. After 1981 something changed here, thats when the Dam operator first began removing the sediment from behind the Big Tujunga dam and trucking elsewhere (prior to 1981 all sediment was passed downstream). Excessive water flows in recent years flushed away the midstream sand bars and sandy rills Arroyo toads need, but scoured riverbeds didn't cause 7a's revocation of critical habitat designation, no! It was "the unlikelyhood of subunit 7a recieving any replenishing sand and gravel", that doomed our toad habitat, due to guess who, the dam operations LACFCD sediment removal policy now exclusively employed, depriving downstream riverine Arroyo Toad habitat of replenishing sand. The use of a MND is not suitable in this case, not until the lower streach of the Big Tujunga River Wash recieves a percentage (as little as 10% will do), of high quality sand from the sediment removal project, a small percentage is easily passed downriver (it could be dredged and sluised with the dewatering of the dam), of the "high value" sand removed from the sediment behind the dam.

      The Big T Dam was recently (2001-2005) retro-fitted with a large sluise bypass, a hydraulic valve designed to pass sediment more naturally. It is currently under 25ft of sediment, apparently never having been utilized. LACFCD assures us in the IS/MND they will consider using the hydraulic gate in the future, after this project is completed!
      The gates and large hydraulic valves could be cleared of accumulated sediment and sand by dredging and passing it downstream during dewatering of the dam. Once cleared, during the storm seasom they can use it to pass sediment more naturally downstream, thereby helping prevent buildup of the additional 2.4 MCF the attached presentation projected to impound behind the Big T Dam during future storms the next 3-5 years.



      Ricky Grubb

      Naturalist and Photographer

      Sunland Tujunga
    • Robert van de Hoek
      Hi Ricky, I liked your narrative about Arroyo Toad. Does the same plight for the Arroyo Toad exist at Pacoima River with the L.A. County dam in Sylmar? Roy
      Message 2 of 2 , Jun 18, 2013
      • 0 Attachment
        Hi Ricky,
        I liked your narrative about Arroyo Toad. Does the same plight for the Arroyo Toad exist at Pacoima River with the L.A. County dam in Sylmar?
        Roy van de Hoek
        Sylmar and Playa del Rey


        From: Bud <nobodyslaw@...>;
        To: <la-river-discuss@yahoogroups.com>;
        Subject: [LAR] Big Tujunga Dam Sediment removal IS/MND
        Sent: Tue, Jun 18, 2013 9:53:14 AM

        Write a letter to on the LACFCD Big Tujunga Sediment removal project IS/MND yet? Please do, ask them to release a small portion of the high quality sand being removed from behind the dam into the river below the dam for the replenishment of Arroyo Toad habitat. We have until june 26th to submit comments. Also Supervisor Antonivitch office is a good place to call and email.

        website  dpw.lacounty.gov/wrd/projects/BigTujunga/

        An MND can only be used (in place of an EIR) if all the projects resulting potentially significant effects are avoided or mitigated to below significance. This IS/MND ignores the project significant impact to Sunland's Arroyo Toad critical habitat (subunit 7a), Arroyo Toads are now extirpated here due to Big Tujunga Dam, the capture and removal of sediment sand and gravel and diversion from our riverbed, that directly caused the revocation of Arroyo Toad critical habitat protection in Sunland's portion of the Big Tujunga River Wash (subunit 7a)! This MND document don't adequately address the indisputably significant impact of the unnatural alteration of riverbed sediment deposition (known as the fluvial process), insisting on removal of all the sand, and releasing none downstream, has a significant impact on the recovery of the Arroyo Toad in Sunland. Lower reach of the river below the Dam was designated final protected critical habitat (subunit 7a) for the recovery of Arroyo Toads. After 1981 something changed here, thats when the Dam operator first began removing the sediment from behind the Big Tujunga dam and trucking elsewhere (prior to 1981 all sediment was passed downstream). Excessive water flows in recent years flushed away the midstream sand bars and sandy rills Arroyo toads need, but scoured riverbeds didn't cause 7a's revocation of critical habitat designation, no! It was "the unlikelyhood of subunit 7a recieving any replenishing sand and gravel", that doomed our toad habitat, due to guess who, the dam operations LACFCD sediment removal policy now exclusively employed, depriving downstream riverine Arroyo Toad habitat of replenishing sand. The use of a MND is not suitable in this case, not until the lower streach of the Big Tujunga River Wash recieves a percentage (as little as 10% will do), of high quality sand from the sediment removal project, a small percentage is easily passed downriver (it could be dredged and sluised with the dewatering of the dam), of the "high value" sand removed from the sediment behind the dam.

        The Big T Dam was recently (2001-2005) retro-fitted with a large sluise bypass, a hydraulic valve designed to pass sediment more naturally. It is currently under 25ft of sediment, apparently never having been utilized. LACFCD assures us in the IS/MND they will consider using the hydraulic gate in the future, after this project is completed!
        The gates and large hydraulic valves could be cleared of accumulated sediment and sand by dredging and passing it downstream during dewatering of the dam. Once cleared, during the storm seasom they can use it to pass sediment more naturally downstream, thereby helping prevent buildup of the additional 2.4 MCF the attached presentation projected to impound behind the Big T Dam during future storms the next 3-5 years.



        Ricky Grubb

        Naturalist and Photographer

        Sunland Tujunga



        ------------------------------------

        Yahoo! Groups Links

        <*> To visit your group on the web, go to:
            http://groups.yahoo.com/group/la-river-discuss/

        <*> Your email settings:
            Individual Email | Traditional

        <*> To change settings online go to:
            http://groups.yahoo.com/group/la-river-discuss/join
            (Yahoo! ID required)

        <*> To change settings via email:
            la-river-discuss-digest@yahoogroups.com
            la-river-discuss-fullfeatured@yahoogroups.com

        <*> To unsubscribe from this group, send an email to:
            la-river-discuss-unsubscribe@yahoogroups.com

        <*> Your use of Yahoo! Groups is subject to:
            http://docs.yahoo.com/info/terms/

      Your message has been successfully submitted and would be delivered to recipients shortly.