RIZ Engineering Study

As a member of the Diamondhead Lake community you owe it to yourself to read the engineering study prepared for the RIZ board by the Howard R Green Company, dated July 2007.

My opinion is that this is a needed tool in the management of the lake and watershed. For an engineering report it is an easy read that seems to make sense.

Our lake has a watershed that is probably too large for the lake that we have, as well as 220 feet of vertical fall in 5 miles of the main tributary, Long Branch Creek.

The study lays out the original design of the dam, the changes that have taken place and the annual events that require road closing for emergency over topping of the road.

The study then identifies various sites/projects to minimize silt infiltration to the lake and then prioritizes them as Phase 1 through Phase 4. Phase 1, as the highest priority is as listed:

1. Development of Dredge Permit Plan. Permit approvals are necessary prior to dredge work.
2. Development of Horse Shoe Bend Sedimentation Basin. Create sediment control at Horse Shoe Bend subwatershed and spoil site for Horse Shoe Bend Dredge/excavation material.
3. Dredge Horse Shoe Bend Area. Complete to provide functional depth in lake.
4. Horse Shoe Bend Subwatershed Sedimentation Basin (Site 7). Construct to add upland containment of sediment in this watershed.
5. Development of Dam/Roadway Crossing Closure Plan. Develop closure plan in accordance with standard road closure practices for roadway when lake overtopping occurs across the roadway.
6. Development of Long Branch Creek/Diamondhead Lake Sedimentation Pond. Provides needed sedimentation control pint at entrance to lake from the significantly large drainage area. Potential for use as any necessary wetland mitigation acreage.
7. Dredge South End of Diamondhead Lake. Dredge and excavate area to create additional lake surface, and more lake depth. Spoil material to existing spoil sites.
8. Erosion Control Ordinance. Control sediment and pollutant flows from lands adjacent to the lake.
9. Channel Erosion Controls. Identify channel reaches requiring treatment. Work with land owners and County Soil and Water District and NRCS for funding and construction.

Phases 2 - 4 follow in the study and I would like to focus on the highest priorities first, so I have not listed Phases 2 - 4.

We appear to have a list of priorities to work on. Where our prior RIZ board was on the highest priorities is not clear to me, but the study should help our new board in its planning.

I was told 12/29/2007 that only 1 copy has been found. Hopefully the others will materialize.

Phil Littler