90 • Wetlands: Their Use and Regulation 



rates that were three times the national average. 

 The Atlantic and gulf coastal zones lost about 

 17,000 acres/yr, or about 0.35 percent of the com- 

 bined regions' wetlands, a little more than half of 

 the national rate. 



Nonvegetated wetlands include about 6 million 

 acres of estuarine and palustrine unconsolidated 

 shore and other types of freshwater open water 

 (areas less than 20 acres in size or less than 2 meters 

 deep). Most of the net gain of about 2 million acres 

 in these nonvegetated wetland types between the 

 mid-1950's and mid-1970's involved the net in- 

 crease of 1 . 7 million acres in freshwater, open water 

 from the "other use" category (i.e., land that 

 formerly was neither wetland, agricultural, or 

 urban). 



Trend Information 



Information from NWTS is the most reliable in- 

 formation available and is used here to identify ma- 

 jor sources of loss. The data has strong statistical 

 validity for nationwide figures on wedand gains and 

 losses and represents what happened to wetlands 

 prior to the implementation of the 404 program. 

 Recent information on how these trends may have 

 changed since the implementation of the 404 pro- 

 gram in the mid-1970's and the initiation of other 

 efforts to control wetland use is available on a 

 qualitative basis only for some regions of the coun- 

 try. Regional information from NWTS and case 

 studies provide less statistically precise trend infor- 

 mation in specific areas of the country. The regional 

 case studies also examine other information sources, 

 including comparative studies and inventories, per- 

 mit data, and personal interviews. 



The recent availability of statistically reliable na- 

 tional estimates of wetlands in the mid-1950's and 

 mid-1970's necessitates a reevaluation of previous 

 estimates of the loss of "original" wetland acreage 

 in the lower 48 States since the time of European 

 settlement. All estimates of "original" acreage are 

 limited by the lack of good data on the amount of 

 land that has been drained or otherwise reclaimed 

 and the relationship between wedands and wetsoils. 

 The following OTA analysis relies on a comparison 

 of wedands reported for the mid- 1 950 's by NWTS 

 (8) and the estimates of reclaimed lands for 1950 

 reported by Wooten (19). To develop an estimate 



of the maximum percentage of reclaimed lands that 

 were wetlands, NWTS data were compared with 

 the difference between improved lands reported by 

 Wooten and agricultural lands on wetsoils in 1977 

 reported by the U.S. Department of Agriculture 

 (USDA) (16). 



The most commonly accepted estimate of 30- to 

 40-percent loss of original wedands is based in part 

 on estimates of wedand acreage both originally and 

 in the 1950's reported in Circular 39 (3,15). In Cir- 

 cular 39, FWS estimated that a minimum of 45 mD- 

 lion acres of wetlands had been reclaimed by the 

 mid-1950's. If this estimate is valid and is added 

 to the 104 million acres of wetlands that NWTS 

 reported for the mid- 1 950 's, then there would have 

 been a minimum of 149 million acres of "original" 

 wedands, not the 127 million estimated by USDA's 

 Soil Conservation Service (SCS). NWTS data, 

 therefore, indicate that FWS Circular 39 estimates 

 were about 20 percent too low. 



The minimum value of 45 million acres of re- 

 claimed wedands by the mid- 1 950 's was developed 

 from data prepared by USDA; however, according 

 to Wooten, a total of 135 million acres had been 

 reclaimed by 1950. Many of these lands were prob- 

 ably just wetsoils, and not wetlands. The relation- 

 ship between wetsoils and wedands cannot be deter- 

 mined with existing information. Recent USDA in- 

 formation on wetsoils is correlated with Circular 

 39 wetland types 3-20 on non-Federal rural lands. 

 NWTS information on wedands uses the new FWS 

 classification that doesn't correspond direcdy to Cir- 

 cular 39 wetland types 3-20, but instead to types 

 1-20. Also, NWTS doesn't distinguish Federal from 

 non-Federal lands. 



Sixty percent of the increase in agricultural land 

 on wetsoils between the mid-1950's and mid-1970's 

 appears to have come from wedands if we compare 

 the difference between improved lands reported by 

 Wooten in the 1950's and agricultural lands on wet- 

 soils in 1977 reported by USDA with NWTS esti- 

 mates of wetlands in the mid-1950's and mid- 

 1970's. This estimated 60 percent compares favor- 

 ably with the estimate discussed later in this 

 chapter, that 65 percent of the lands drained be- 

 tween 1955 and 1975 were wedands. Assuming that 

 the proportion of wetlands to wetsoils that are be- 

 ing converted to agricultural use probably has been 

 increasing over time (since it's probably easier to 



