SSurveying in Louisianatakes on as many flavorsas there are recipes forgumbo. Where else mighta surveyor have to subdi-vide section 103 in a

GLO surveyed township? Or use longbamboo in saltwater bays to mark thelimits of oyster leases using a 1' transit,with sights on the horizon for locationtaken from quad maps? In the southernpart of the state one’s initiation to afield crew likely includes taking cross-sections of a bayou or canal, egged onat least until the water is breast deep. Inthe north one might spend time findinga pine knot or sifting ashes of below-ground stumps to identify a section cor-ner.

Ingenious techniques and technolo-gies were developed when scientificresearch demanded new information,when oil exploration required accurateand timely location of geologic informa-tion, and when pipeline companiesneeded to purchase and follow rights ofway. Louisiana's history of land claimsby Europeans dates back to the early16th century. Alvarez de Pineda discov-ered the mouth of the Mississippi Riverin 1519. Perhaps the firstsurveyor was 1541Hernando De Soto, wholed the first group ofwhite men to travel downthe Mississippi River tothe Gulf of Mexico in1543. The first survey forspeculators was done byFrench Canadians PéreJacques Marquette, S.J., andLouis Joliet who followedthe grande riviéré to itsmouth in 1673 and estab-

lished that it emptied into the Gulf ofMexico. This, in turn, led to the imme-diate formation of plans by theCanadians for settlement of theMississippi Valley. Robert Cavalier,Sieur de la Salle,erected a cross atthe mouth of theMississippi Riverafter descendingthe Mississippifrom the GreatLakes claimingand naming the terri-tory for Louis XIVin 1682. That’s 485years of surveyingin Louisiana!(Figures 1 and 2)

Ten flags haveflown over Louisiana and landrights often originate with Spanish,French, English or American grants.Each brought various customs of meas-urement and description, from the arpentand vara to the French foot and descrip-tion in ' (foot) " (inches) and "' (lines).

The importance of water traffic canbe seen in many of the grants andclaims that tend to be longer than they

are wide as they radiate from the rivers,lakes and bayous. The Surveyor Generalinstructed his deputies to survey radiat-ing sections along navigable streams

Surveying Louisiana

Americathe fabric ofSurveying

First in a series that will focus on unique

wrinkles in our survey heritage.

By J. Anthony Cavell, LS

The story of Louisiana is like good gumbo: the main ingredient is New Orleans,the roux is the Mississippi River, and whatever goes in after that is up to the cook.

Louisiana asProposedIncluded Florida West &Neutral Ground with Texas

Figure 1 Louisiana was originally pro-posed as shown in this illustration with12 counties, no man’s land called“Neutral Ground” to the west, and whatwas once the English colony, WestFlorida, which extended to the PerdidoRiver (Florida’s western boundarytoday). Early capitals of Louisiana werelocated near Biloxi and Mobile. Fearfulof the influence of the English speakerson the local culture, Louisianians reject-ed most of West Florida, acceptingwhat is west of the Pearl River (an areastill known as the Florida Parishes).Parts of Mississippi and Alabama wereformed from the remainder. Today,Louisiana surveyors still find interestingremnants of influence from the NeutralGround and West Florida.Figure 2 There are 64 parishes in Louisiana today. The term

“county” was too English and too Protestant for Louisiana sensibilities at the time.

Louisiana200464 Parishes

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before dividing the remaining land intosquare sections. The surveyors were fur-ther instructed to plot all approved pri-vate grants before surveying public lands.Most of the grants had been surveyedprivately and the claims followed naturalboundaries or adjoiners so their rightswere easily recognized. Not all the publiclands were surveyed, particularly those inthe swampy or marshy areas, which stillresults in many court disputes to courtbetween land owners and the state whereoil is involved, especially concerningrights to land underwater that is notshown as such in original plats. (Figures3, 4 & 5).

Surveying, especially in the southernportions of Louisiana, often involveswater. The largest North Americanfreshwater swamp is the AtchafalayaSwamp that lies in between BatonRouge and Lafayette. The delta createdby the Mississippi River forms the toeof the boot. Saltwater marsh makes up

much of the coastinland from theGulf. Precise posi-tioning in theseconditionsrequires ingenuity.On the movingplatform of asmall boat, oftenthe best proof of aline laid straightly is had by sighting the“picket fence of flagged poles placedbetween PIs.

Radios were mandatory as soon asthey were small enough to carry intothe boat. Most positioning or surveyingin these conditions involved triangulat-ing with two transits set up someplacesolid calling angles to the Party Chiefon the spot in the boat. Moderntheodolites with compensators were toomotion-sensitive to be useful. Many oilwells were spotted and pipelines laid inthis way. As oil exploration left the

inland marshes and ventured offshoreinto the Gulf of Mexico, these sametechniques were applied. As the wellswent further out, the surveyors movedto the tops of buildings on the beach orbuilt scaffolds. When they went furtherstill, pilings were driven and surveyedin then occupied by the surveyors tosee out even further. Eventually, withpermanent platforms constructed,points on the platforms were surveyedand occupied as control points.

South Louisiana surveyors wereamong the first to make use of EDMs.In the marsh, and particularly offshore,there was often a haze that could frus-trate an observer looking through atransit telescope. What he could seewith the naked eye was invisiblethrough his instrument. Many positionswere shot using a crude version ofheliotrope to flash each other. Using theplatform’s control points, each instru-

ment man would aim his instrument toa good estimate of where the othershould be. Then, taking turns, theywould flash sunlight along the axis ofthe telescope which was more easily seenand measured. All too often, however,even this trick wouldn’t work, whichwould mean a delay until conditionsimproved, possibly at night when theycould shoot lights.

This led to the development ofmicrowave ranging. Whenever condi-

Figure 3 Plat from Nov. 21, 1854 showing portion of thecity of Lafayette where the author now resides.

Figure 4 Color version of the same map.

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tions became marginal, the surveyorwould leave his transit and fire up hisAutotape or one of the other EDMdevices. Then by twirling knobs, andlater reading indicators, the rangescould be determined. When the rangeof these devices was insufficient, theingenious surveyor would put two unitsin a plane and the mate for each at thepoints of interest, then fly across their

line and note the minimum ranges,allow for altitude, and voila, he was on.

It was a natural progression of thisdrive and ingenuity that led JohnChance and Associates to take one ofthe rejected ideas proposed for GPSand develop it into STARFIX the onlyprivately owned satellite positioningsystem which they used successfullyfor several years before GPS became

practical. STARFIX was awarded theU.S. Senate Innovation Award in1989. Today several Louisiana firmsare leaders in the development and useof GIS, LiDAR, SONAR and ROVs.

Morgan City and New Orleans aretowns surrounded by levees. TheFEMA finished floor elevation inmuch of New Orleans is -4 MSL!Looking up to watch huge freighterspass nearby above head level is aneveryday experience in SouthLouisiana.

Figure 5 One result of the radiating river lots and private claims is that severalsections contain more than a hundred numbered sections. This plat from Sept.21, 1837 shows a township across the Mississippi River west of Baton Rouge.

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For many years it was observablethat the Gulf has been pushing backthe coastline. One public serviceannouncement harkened, “We are los-ing a football field of coast every 20minutes!” Louisiana serves as nurseryfor much of the world’s fisheries andsupplies huge amounts of seafood pro-duce, almost all of which spawns,hatches, or is nurtured in Louisiana’sswamps and marshes.

The easy first targets for blame forthe shrinking coastline is the Corps ofEngineers (for sending the millions oftons of river sediment off the continen-tal shelf instead of the wetlands) andthe oil companies (for canals andtransportation across the marsh, aggra-vating saltwater intrusion). Whilethese practices are damaging, theyweren’t understood as such whenplanned. The readjustment of the ver-tical network by NGS in the 1980swas sidetracked a tad by suggestionsby Professor Mugnier of LSU, (then atUNO) who suggested, based on gravi-ty data, that NGS should re-level someof Louisiana first. NGS did so, anddiscovered a nearly one foot reductionin the values published for benchmarks in the Southeast Louisiana area!With that information, surveyors werefaced with the terrible task of havingto explain why someone’s house hadto be built a whole foot higher thanhis neighbor’s house that had beenbuilt only a few months earlier.

This information and more led toincreased awareness and research intothe Gulf’s encroachment and the real-ization that the problem wasn’t a sim-ple one. There was erosion, but it wastoo simple to just blame oilfield canals.There was also compaction, but againit was too simple to blame just theCorps for dumping the Mississippi’ssediments. Louisiana has tectonic

activity equalto that of California,but it is cushioned by allthe “goo”, and the deeper stuff issimply going down (subsidence), andbending like a springboard (flexure).The rate is often 12mm/yr and higher(6-10 inches per decade)! NGS report-ed to Congress that there are no reli-able bench marks in south Louisiana!

With this information and help fromNGS and support from Congress,LSU is now home to the LouisianaSpatial Reference Center (LSRC).Prominent there are Dr. Dokka andProfessor Mugnier. Louisiana has alsohad the long time benefit of NGS StateAdvisor “Bob” Zurfluh who retiredDec. 31, 2003. The LSRC has begunconstructing a network of CORScalled GulfNet to span all of the state,

starting on the south and working upfrom there. Louisiana surveyors arenow regularly using these 21st centurybench marks. NGS now accounts forthe vertical velocity of many marks inLouisiana. (The author is presentlyengaged in some quality control sur-veys ultimately for the FEMA pro-gram to update the flood maps inLouisiana.) With the official proclama-

tion that there are no reliable benchmarks, the only contemporary refer-ences to the national control systemare the CORS, so the decision to usesubstantial occupation times and pro-cessing using NGS OPUS service wasmade. Then, using the establishedTBMs and RTK we move around anddouble shoot the samples. Thoseplaces not suitable for GPS, such aswooded areas, are shot conventionallyusing a total station from point pairsset with the RTK. The results havebeen gratifying so far.

Louisiana is known as Sportsman’sParadise, the Pelican State, the BayouState, Creole State, and Child of theMississippi. It’s home to Mardi Gras,Tabasco, andouille, etouffees, saucepiquantes, cayenne pepper, crawfish,and the sounds of jazz, blues and zyde-co. Her heritage exceeds all in diversity.It’s fun to be a surveyor here, to deal inreal history both recent and long past.Like good gumbo, words don’t do itjustice. You just have to taste it.

Tony Cavell is a land surveyor, consultant and speaker. Licensedin Louisiana, he manages theLouisiana office of ESP Associates,and enjoys presenting seminars.

For many years it was observable that the

Gulf has been pushing back the coastline.

One public service announcement

harkened, “We are losing a football field

of coast every 20 minutes!”

USGA Data forLouisiana

Public SurveyLand GrantsUnsurveyedWater

Figure 6 This map was drawn fromdata available on the USGS website,and indicates the status of the USPublic Lands surveys in Louisiana.Portions labeled as Land Grants represent private claims and radiating river lots.

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