Tag Archives: sediment removal cost

How much does Dredging cost?

How much does dredging cost is the most commonly asked question for many lake associations.  We sat down with Dan McDougal, President of Dredge America and asked him that question.  

When lake homeowner’s call for our assistance with their potential upcoming dredging projects, the first question we usually get asked is, “How much does it cost?” This is usually followed by, “Just a ballpark figure that I won’t hold you to.” Then we often hear, “We have a board meeting tonight and I wanted to report on dredging to get the project moving.”

There are hundreds of variables that determine the cost of restoring a lake. There are three questions that need to be answered to begin the process of getting a ballpark feasibility price:

  1. How much material is there to dredge?
  2. Where can you put the material that is coming out of the lake?
  3. What is the nature of the material to be dredged?

In order to determine a quantity, the first thing that is required is to perform a pre-dredge hydrographic survey (bathymetry).  This type of survey will provide water depth information throughout the entire body of water.  At the same time a sediment survey can be performed providing soft sediment thickness information.

It is money well spent at this stage to hire an experienced hydrographic surveyor with proper insurance and credentials.  This will help protect the association if there is ever a dispute.  The hyrdrographer will be able to give a general description for the soil characteristics and perform the sub-bottom profiling all in one site visit. With this information, you can make an informed decision about how much more data is needed in order to get the most cost effective proposal for your dredging project.

After you have quantified how much sediment needs to be removed, the next step is to find a place to put it. Most people underestimate the amount of space they need to place and contain the sediment that comes out of the lake.  The size of area you will need will depend on many factors with the number one being the lay of the land. Usually for every two acres of lake that you dredge, an average of three foot of sediment, you will need an acre of upland area to place the material. This will yield an average elevation increase of six feet on land prior to consolidation.  The closer this area to the lake, the cheaper the dredging costs will be with all other things being equal. 

The final question to answer is the material characteristics. In most lakes, what is being dredged is often referred to as “muck.” This is generally a combination of silt, clay, and organics. There is also sometimes sand in the very end of the coves. The dredger needs to know this as sand is more costly to pump further, but easier to dewater; while muck pumps easy, but can be costly to dewater, particularly if the disposal area size is limited. Hard packed sand, or hard pan clay bottom, are more difficult to cut, and therefore more expensive. Rock is even more expensive and most often cost prohibitive. There should be a clear distinction if the dredger is expected to only remove sediment that has filled the lake since it was originally constructed, verses cut virgin ground that has never been excavated.

It is best to work with someone with many years of dredging experience to help guide you through the maze and advise you on what is needed, not needed, and what options you can elect for the associated costs. In the end, you want someone you can trust with a long history and who can supply you with pages of references. The very last thing you want is someone to learn about dredging on your project and on your dime.

So is your project feasible? If you can’t afford to have someone qualified come out and perform a hydrographic survey, the answer is no. If you can do this, then you can have a quantity and a three dimensional image of your lake bottom.  With this critical information you can communicate with your neighbors on what the problem is, where it is, and a ballpark of what it might cost to fix it.

One final thing to consider is that all lake associations have more mud than money. With the hydrographic survey, you can set your priorities based on a realistic budget that your association is willing to spend. You and all of your neighbors live on a lake for a reason. It is a lifestyle. Your lake has to be maintained just like your roads and your sewers. To ignore it, is to ignore the largest asset in your community. Property values go down or up based on the quality of the lake.

If you have anymore questions for Dan McDougal, feel free to email

or call him 800.464.5597.  You can also visit their website for more information.

The Mapping Network surveyed the bottom of the lake including the sediment depths. This map shows the lake water depth as blue contours lines as well as a color shaded sediment thickness. This specialized technology allows the POA to easily locate problem areas.
The Mapping Network surveyed the bottom of the lake including the sediment depths. This map shows the lake water depth as blue contours lines as well as a color shaded sediment thickness. This specialized technology allows the POA to easily locate problem areas.

The Mapping Network surveyed the bottom of the lake including the sediment depths. This map shows the lake water depth as blue contours lines as well as a color shaded sediment thickness. This specialized technology allows the POA to easily locate problem areas.

The Mapping Network is an industry leader in Hydrographic Surveys, Bathymetry, Geographic Information Systems Consulting, Data Conversion, and GPS Data Collection.  We specialize in terrain and sub-surface (bathymetry) GPS mapping.   If you are serious about maintaining  a high-quality golf course, lake or pond, be sure you have the ability to make the best decisions,  get your resource mapped by the professionals at The Mapping Network.   Give us a call or send an e-mail to find out more details.

phone:  (402) 241-8177

e-mail: info@themappingnetwork.com

website: www.themappingnetwork.com

Check out The Mapping Network on Facebook for more examples and success stories!

Sediment Mapping Saves POA Hundreds of Thousands of Dollars in Dredging Costs

by Trent Lewis (Pond Medics, Inc.)

We recently worked with Lakeside on Preston HOA, in Plano, on their dredging project. The lakes in the community were approaching 18 years old and sediment had accumulated in the lakes to the extent islands had formed as if there were underwater volcanoes erupting and new land was emerging! Lakeside knew dredging was imminent, so they called several dredging contractors and asked them to submit quotes to perform the work. What they received from the contractors was a multitude of different opinions on what the lake bottom looked like and what needed to be dredged. As a result, they had many different quotes to choose from. But, what was the right choice? Our work began when the lakes and landscape committee chairman called us for help.

Mapping the lakes was the best option for fully understanding the severity of the sediment issues.  Once the maps were complete, a meeting was organized to review the maps and determine the areas the HOA deemed most important to dredge. This would help focus the dredging efforts and help reduce overall dredging expenses. Using the data we collected to make the bathymetric map, we were able to calculate the cubic yardage of sediment needed to be removed in the critical areas the HOA identified. Now, Lakeside on Preston had objective, hard data from which to ask for dredging quotes. It was no longer subjective to what the dredging company thought needed to be done. For the first time in the Lakeside dredging project, the community was at the helm. The critical dredging area data was tabulated, formatted into a visual exhibit, included in a new Request for Proposal (RFP) and present to the dredging contractors.

 The new dredging proposals were received two weeks later and reviewed. The first time Lakeside did this, they received quotes that varied in excess of 300% from one contractor to another. This time, after our new RFP was sent out, we received quotes that were within several thousand dollars of each other. Finally, Lakeside was able to compare “apples to apples” between dredging contractors. Why? All the contractors were all looking at, and bidding from, the same data.  Shortly thereafter, Lakeside on Preston chose a dredging contractor to perform the work and dredging began. PondMedics stayed on to assist the HOA with the project administration. The dredging contractor used the maps to help locate the areas they were contracted to dredge.

When all the lakes were completely dredged, we re‐mapped the lakes.  Because we were able to map the lakes prior to dredging, we could now provide Lakeside on Preston HOA a complete set of “before and after” maps. An otherwise unseen world, was now revealed to the community and everyone was able to see the underwater changes. Lakeside on Preston will present the completed project to the residents during the spring Annual Meeting, using the before/after maps to demonstrate to the residents how their money was used effectively in this dredging project and how the lake maps saved the POA hundreds of thousands of dollars.

Larry Hairston, a member of the board of directors and the lake committee chairperson for Lakeside on Preston HOA summarized it this way:

“When I first looked at the proposal the HOA had previously obtained it was in the neighborhood of $450,000 to perform the dredging. By going to multiple vendors with the information you [PondMedics, Inc.]supplied, the prices eventually came down and the final cost is in the neighborhood of $200,000. I am certain we saved well over $200,000 by competitively bidding the projects, but more specifically by determining the amount of silt to be removed. The other valuable service PondMedics performed was confirmation of satisfactory completion by the dredging company, using the mapping technology.”

A color-shaded sediment map created by The Mapping Network. Our automated sediment mapping system can precisely locate problems areas needing to be dredged. Knowing exactly where to remove sediment not only saves the client money, but protects the environment by limiting the extent of the dredging footprint.

The Mapping Network is an industry leader in Geographic Information Systems Consulting, Data Conversion, and GPS Data Collection.  We specialize in terrain and sub-surface (bathymetry) GPS mapping.   If you are serious about maintaining  a high-quality golf course, lake or pond, be sure you have the ability to make the best decisions,  get your resource mapped by the professionals at The Mapping Network.   Give us a call or send an e-mail to find out more details.

phone:  (402) 241-8177

e-mail: info@themappingnetwork.com

website: www.themappingnetwork.com

Check out The Mapping Network on Facebook for more examples and success stories!

The Mapping Network is proud to announce their firm has been chosen by Cabela’s, the World’s Foremost Outfitter, as a Landowner Services provider for Cabela’s Trophy Properties throughout the United States.  Visit us on the Cabela’s Trophy Properties website >> click here

The Mapping Network:  www.TheMappingNetwork.com