<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.irs.gov/efile" returnVersion="2022v5.0">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2023-11-02T10:07:10-05:00</ReturnTs>
    <TaxPeriodEndDt>2022-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>521392008</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>GELMAN ROSENBERG &amp; FREEDMAN</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>4550 MONTGOMERY AVE SUITE 800N</AddressLine1Txt>
        <CityNm>BETHESDA</CityNm>
        <StateAbbreviationCd>MD</StateAbbreviationCd>
        <ZIPCd>208142930</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990PF</ReturnTypeCd>
    <TaxPeriodBeginDt>2022-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>263402690</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>DELTARES USA INC</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>DELT</BusinessNameControlTxt>
      <PhoneNum>3016422505</PhoneNum>
      <USAddress>
        <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
        <CityNm>SILVER SPRING</CityNm>
        <StateAbbreviationCd>MD</StateAbbreviationCd>
        <ZIPCd>20910</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>EDWIN WELLES</PersonNm>
      <PersonTitleTxt>DIRECTOR</PersonTitleTxt>
      <PhoneNum>3016422505</PhoneNum>
      <SignatureDt>2023-11-02</SignatureDt>
      <DiscussWithPaidPreparerInd>1</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <SigningOfficerGrp>
      <PersonFullName>
        <PersonFirstNm>EDWIN</PersonFirstNm>
        <PersonLastNm>WELLES</PersonLastNm>
      </PersonFullName>
      <SSN>999009999</SSN>
    </SigningOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>0</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>RICHARD J LOCASTRO CPA</PreparerPersonNm>
      <PTIN>P00288314</PTIN>
      <PhoneNum>3019519090</PhoneNum>
    </PreparerPersonGrp>
    <AdditionalFilerInformation>
      <TrustedCustomerGrp>
        <TrustedCustomerCd>2</TrustedCustomerCd>
        <AuthenticationAssuranceLevelCd>AAL1</AuthenticationAssuranceLevelCd>
        <IdentityAssuranceLevelCd>IAL1</IdentityAssuranceLevelCd>
      </TrustedCustomerGrp>
    </AdditionalFilerInformation>
    <TaxYr>2022</TaxYr>
    <BuildTS>2023-04-26 12:10:37Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="7">
    <IRS990PF documentId="RetDoc1235000001">
      <Organization501c3ExemptPFInd>X</Organization501c3ExemptPFInd>
      <FMVAssetsEOYAmt>2638806</FMVAssetsEOYAmt>
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <AnalysisOfRevenueAndExpenses>
        <ScheduleBNotRequiredInd>X</ScheduleBNotRequiredInd>
        <InterestOnSavRevAndExpnssAmt>7</InterestOnSavRevAndExpnssAmt>
        <InterestOnSavNetInvstIncmAmt>7</InterestOnSavNetInvstIncmAmt>
        <InterestOnSavingsAdjNetIncmAmt>7</InterestOnSavingsAdjNetIncmAmt>
        <CapGainNetIncmNetInvstIncmAmt>0</CapGainNetIncmNetInvstIncmAmt>
        <NetSTCapitalGainAdjNetIncmAmt>0</NetSTCapitalGainAdjNetIncmAmt>
        <OtherIncomeRevAndExpnssAmt referenceDocumentId="RetDoc2001500001">5738844</OtherIncomeRevAndExpnssAmt>
        <OtherIncomeNetInvstIncmAmt>0</OtherIncomeNetInvstIncmAmt>
        <OtherIncomeAdjNetIncmAmt>5738844</OtherIncomeAdjNetIncmAmt>
        <TotalRevAndExpnssAmt>5738851</TotalRevAndExpnssAmt>
        <TotalNetInvstIncmAmt>7</TotalNetInvstIncmAmt>
        <TotalAdjNetIncmAmt>5738851</TotalAdjNetIncmAmt>
        <CompOfcrDirTrstRevAndExpnssAmt>193479</CompOfcrDirTrstRevAndExpnssAmt>
        <CompOfcrDirTrstNetInvstIncmAmt>0</CompOfcrDirTrstNetInvstIncmAmt>
        <CompOfcrDirTrstAdjNetIncmAmt>19348</CompOfcrDirTrstAdjNetIncmAmt>
        <CompOfcrDirTrstDsbrsChrtblAmt>174131</CompOfcrDirTrstDsbrsChrtblAmt>
        <OthEmplSlrsWgsRevAndExpnssAmt>749780</OthEmplSlrsWgsRevAndExpnssAmt>
        <OthEmplSlrsWgsNetInvstIncmAmt>0</OthEmplSlrsWgsNetInvstIncmAmt>
        <OthEmplSlrsWgsAdjNetIncmAmt>74978</OthEmplSlrsWgsAdjNetIncmAmt>
        <OthEmplSlrsWgsDsbrsChrtblAmt>670205</OthEmplSlrsWgsDsbrsChrtblAmt>
        <PensionEmplBnftRevAndExpnssAmt>238604</PensionEmplBnftRevAndExpnssAmt>
        <PensionEmplBnftNetInvstIncmAmt>0</PensionEmplBnftNetInvstIncmAmt>
        <PensionEmplBnftAdjNetIncmAmt>23860</PensionEmplBnftAdjNetIncmAmt>
        <PensionEmplBnftDsbrsChrtblAmt>216633</PensionEmplBnftDsbrsChrtblAmt>
        <LegalFeesRevAndExpnssAmt referenceDocumentId="RetDoc2002100001">48868</LegalFeesRevAndExpnssAmt>
        <LegalFeesNetInvstIncmAmt>0</LegalFeesNetInvstIncmAmt>
        <LegalFeesAdjNetIncmAmt>0</LegalFeesAdjNetIncmAmt>
        <LegalFeesDsbrsChrtblAmt>48036</LegalFeesDsbrsChrtblAmt>
        <AccountingFeesRevAndExpnssAmt referenceDocumentId="RetDoc2002200001">69475</AccountingFeesRevAndExpnssAmt>
        <AccountingFeesNetInvstIncmAmt>0</AccountingFeesNetInvstIncmAmt>
        <AccountingFeesAdjNetIncmAmt>0</AccountingFeesAdjNetIncmAmt>
        <AccountingFeesChrtblPrpsAmt>38581</AccountingFeesChrtblPrpsAmt>
        <OtherProfFeesRevAndExpnssAmt referenceDocumentId="RetDoc2002300001">4222455</OtherProfFeesRevAndExpnssAmt>
        <OtherProfFeesNetInvstIncmAmt>0</OtherProfFeesNetInvstIncmAmt>
        <OtherProfFeesAdjNetIncmAmt>0</OtherProfFeesAdjNetIncmAmt>
        <OtherProfFeesDsbrsChrtblAmt>4332898</OtherProfFeesDsbrsChrtblAmt>
        <DeprecAndDpltnRevAndExpnssAmt>12205</DeprecAndDpltnRevAndExpnssAmt>
        <DeprecAndDpltnNetInvstIncmAmt>0</DeprecAndDpltnNetInvstIncmAmt>
        <DeprecAndDpltnAdjNetIncmAmt>12205</DeprecAndDpltnAdjNetIncmAmt>
        <OccupancyRevAndExpnssAmt>29281</OccupancyRevAndExpnssAmt>
        <OccupancyNetInvstIncmAmt>0</OccupancyNetInvstIncmAmt>
        <OccupancyAdjNetIncmAmt>0</OccupancyAdjNetIncmAmt>
        <OccupancyDsbrsChrtblAmt>29281</OccupancyDsbrsChrtblAmt>
        <TravConfMeetingRevAndExpnssAmt>65268</TravConfMeetingRevAndExpnssAmt>
        <TravConfMeetingNetInvstIncmAmt>0</TravConfMeetingNetInvstIncmAmt>
        <TravConfMeetingAdjNetIncmAmt>0</TravConfMeetingAdjNetIncmAmt>
        <TravConfMeetingDsbrsChrtblAmt>66834</TravConfMeetingDsbrsChrtblAmt>
        <OtherExpensesRevAndExpnssAmt referenceDocumentId="RetDoc2003200001">204915</OtherExpensesRevAndExpnssAmt>
        <OtherExpensesNetInvstIncmAmt>0</OtherExpensesNetInvstIncmAmt>
        <OtherExpensesAdjNetIncmAmt>0</OtherExpensesAdjNetIncmAmt>
        <OtherExpensesDsbrsChrtblAmt>200212</OtherExpensesDsbrsChrtblAmt>
        <TotOprExpensesRevAndExpnssAmt>5834330</TotOprExpensesRevAndExpnssAmt>
        <TotOprExpensesNetInvstIncmAmt>0</TotOprExpensesNetInvstIncmAmt>
        <TotOprExpensesAdjNetIncmAmt>130391</TotOprExpensesAdjNetIncmAmt>
        <TotOprExpensesDsbrsChrtblAmt>5776811</TotOprExpensesDsbrsChrtblAmt>
        <ContriPaidRevAndExpnssAmt>0</ContriPaidRevAndExpnssAmt>
        <ContriPaidDsbrsChrtblAmt>0</ContriPaidDsbrsChrtblAmt>
        <TotalExpensesRevAndExpnssAmt>5834330</TotalExpensesRevAndExpnssAmt>
        <TotalExpensesNetInvstIncmAmt>0</TotalExpensesNetInvstIncmAmt>
        <TotalExpensesAdjNetIncmAmt>130391</TotalExpensesAdjNetIncmAmt>
        <TotalExpensesDsbrsChrtblAmt>5776811</TotalExpensesDsbrsChrtblAmt>
        <ExcessRevenueOverExpensesAmt>-95479</ExcessRevenueOverExpensesAmt>
        <NetInvestmentIncomeAmt>7</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>5608460</AdjustedNetIncomeAmt>
      </AnalysisOfRevenueAndExpenses>
      <Form990PFBalanceSheetsGrp>
        <CashBOYAmt>2137613</CashBOYAmt>
        <CashEOYAmt>1813938</CashEOYAmt>
        <CashEOYFMVAmt>1813938</CashEOYFMVAmt>
        <AcctRcvblAmt>789416</AcctRcvblAmt>
        <AcctRcvblBOYAmt>552280</AcctRcvblBOYAmt>
        <AcctRcvblEOYAmt>789416</AcctRcvblEOYAmt>
        <AcctRcvblEOYFMVAmt>789416</AcctRcvblEOYFMVAmt>
        <PrepaidExpensesBOYAmt>16970</PrepaidExpensesBOYAmt>
        <PrepaidExpensesEOYAmt>9910</PrepaidExpensesEOYAmt>
        <PrepaidExpensesEOYFMVAmt>9910</PrepaidExpensesEOYFMVAmt>
        <LandBldgEquipCostOrOtherBssAmt>79933</LandBldgEquipCostOrOtherBssAmt>
        <LandBldgEquipAccumDeprecAmt>55849</LandBldgEquipAccumDeprecAmt>
        <LandBOYAmt>19961</LandBOYAmt>
        <LandEOYAmt>24084</LandEOYAmt>
        <LandEOYFMVAmt>24084</LandEOYFMVAmt>
        <OtherAssetsBOYAmt referenceDocumentId="RetDoc2046600001">1458</OtherAssetsBOYAmt>
        <OtherAssetsEOYAmt referenceDocumentId="RetDoc2046600001">1458</OtherAssetsEOYAmt>
        <OtherAssetsEOYFMVAmt referenceDocumentId="RetDoc2046600001">1458</OtherAssetsEOYFMVAmt>
        <TotalAssetsBOYAmt>2728282</TotalAssetsBOYAmt>
        <TotalAssetsEOYAmt>2638806</TotalAssetsEOYAmt>
        <TotalAssetsEOYFMVAmt>2638806</TotalAssetsEOYFMVAmt>
        <AccountsPayableBOYAmt>625145</AccountsPayableBOYAmt>
        <AccountsPayableEOYAmt>545213</AccountsPayableEOYAmt>
        <DeferredRevenueBOYAmt>1413092</DeferredRevenueBOYAmt>
        <DeferredRevenueEOYAmt>1499027</DeferredRevenueEOYAmt>
        <TotalLiabilitiesBOYAmt>2038237</TotalLiabilitiesBOYAmt>
        <TotalLiabilitiesEOYAmt>2044240</TotalLiabilitiesEOYAmt>
        <OrganizationFollowsFASB117Ind>X</OrganizationFollowsFASB117Ind>
        <NoDonorRstrNetAssestsBOYAmt>690045</NoDonorRstrNetAssestsBOYAmt>
        <NoDonorRstrNetAssestsEOYAmt>594566</NoDonorRstrNetAssestsEOYAmt>
        <TotNetAstOrFundBalancesBOYAmt>690045</TotNetAstOrFundBalancesBOYAmt>
        <TotNetAstOrFundBalancesEOYAmt>594566</TotNetAstOrFundBalancesEOYAmt>
        <TotalLiabilitiesNetAstBOYAmt>2728282</TotalLiabilitiesNetAstBOYAmt>
        <TotalLiabilitiesNetAstEOYAmt>2638806</TotalLiabilitiesNetAstEOYAmt>
      </Form990PFBalanceSheetsGrp>
      <ChgInNetAssetsFundBalancesGrp>
        <TotNetAstOrFundBalancesBOYAmt>690045</TotNetAstOrFundBalancesBOYAmt>
        <ExcessRevenueOverExpensesAmt>-95479</ExcessRevenueOverExpensesAmt>
        <OtherIncreasesAmt>0</OtherIncreasesAmt>
        <SubtotalAmt>594566</SubtotalAmt>
        <OtherDecreasesAmt>0</OtherDecreasesAmt>
        <TotNetAstOrFundBalancesEOYAmt>594566</TotNetAstOrFundBalancesEOYAmt>
      </ChgInNetAssetsFundBalancesGrp>
      <ExciseTaxBasedOnInvstIncmGrp>
        <InvestmentIncomeExciseTaxAmt>0</InvestmentIncomeExciseTaxAmt>
        <TaxUnderSection511Amt>0</TaxUnderSection511Amt>
        <SubtotalAmt>0</SubtotalAmt>
        <SubtitleATaxAmt>0</SubtitleATaxAmt>
        <TaxBasedOnInvestmentIncomeAmt>0</TaxBasedOnInvestmentIncomeAmt>
        <EstimatedPlusOvpmtIncmTxAmt>0</EstimatedPlusOvpmtIncmTxAmt>
        <ExemptFrgnOrgTaxWthldAtSrceAmt>0</ExemptFrgnOrgTaxWthldAtSrceAmt>
        <ExtsnRequestIncomeTaxPaidAmt>0</ExtsnRequestIncomeTaxPaidAmt>
        <BackupWithholdingWithheldAmt>0</BackupWithholdingWithheldAmt>
        <TotalPaymentsAndCreditsAmt>0</TotalPaymentsAndCreditsAmt>
        <EsPenaltyAmt>0</EsPenaltyAmt>
        <TaxDueAmt>0</TaxDueAmt>
      </ExciseTaxBasedOnInvstIncmGrp>
      <StatementsRegardingActyGrp>
        <LegislativePoliticalActyInd>0</LegislativePoliticalActyInd>
        <MoreThan100SpentInd>0</MoreThan100SpentInd>
        <Form1120POLFiledInd>0</Form1120POLFiledInd>
        <Section4955OrganizationTaxAmt>0</Section4955OrganizationTaxAmt>
        <Section4955ManagersTaxAmt>0</Section4955ManagersTaxAmt>
        <TaxReimbursedAmt>0</TaxReimbursedAmt>
        <ActivitiesNotPreviouslyRptInd>0</ActivitiesNotPreviouslyRptInd>
        <ChangesToArticlesOrBylawsInd>0</ChangesToArticlesOrBylawsInd>
        <UnrelatedBusIncmOverLimitInd>0</UnrelatedBusIncmOverLimitInd>
        <OrganizationDissolvedEtcInd>0</OrganizationDissolvedEtcInd>
        <Section508eRqrSatisfiedInd>1</Section508eRqrSatisfiedInd>
        <AtLeast5000InAssetsInd>1</AtLeast5000InAssetsInd>
        <OrgReportOrRegisterStateCd>MD</OrgReportOrRegisterStateCd>
        <OrgReportOrRegisterStateCd>CA</OrgReportOrRegisterStateCd>
        <Form990PFFiledWithAttyGenInd>1</Form990PFFiledWithAttyGenInd>
        <PrivateOperatingFoundationInd>1</PrivateOperatingFoundationInd>
        <NewSubstantialContributorsInd>0</NewSubstantialContributorsInd>
        <OwnControlledEntityInd>0</OwnControlledEntityInd>
        <DonorAdvisedFundInd>0</DonorAdvisedFundInd>
        <ComplyWithPublicInspRqrInd>1</ComplyWithPublicInspRqrInd>
        <WebsiteAddressTxt>N/A</WebsiteAddressTxt>
        <PersonsWithBooksName>
          <BusinessNameLine1Txt>MANDY GETZ</BusinessNameLine1Txt>
        </PersonsWithBooksName>
        <PhoneNum>3016422505</PhoneNum>
        <LocationOfBooksUSAddress>
          <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
          <CityNm>SILVER SPRING</CityNm>
          <StateAbbreviationCd>MD</StateAbbreviationCd>
          <ZIPCd>20910</ZIPCd>
        </LocationOfBooksUSAddress>
        <ForeignAccountsQuestionInd>1</ForeignAccountsQuestionInd>
        <ForeignCountryCd>CA</ForeignCountryCd>
      </StatementsRegardingActyGrp>
      <StatementsRegardingActy4720Grp>
        <SaleOrExchDisqualifiedPrsnInd>0</SaleOrExchDisqualifiedPrsnInd>
        <BrrwOrLendDisqualifiedPrsnInd>0</BrrwOrLendDisqualifiedPrsnInd>
        <FurnGoodsDisqualifiedPrsnInd>0</FurnGoodsDisqualifiedPrsnInd>
        <PayCompDisqualifiedPrsnInd>1</PayCompDisqualifiedPrsnInd>
        <TransferAstDisqualifiedPrsnInd>0</TransferAstDisqualifiedPrsnInd>
        <PaymentToGovernmentOfficialInd>0</PaymentToGovernmentOfficialInd>
        <ActsFailToQlfyAsExceptionsInd>0</ActsFailToQlfyAsExceptionsInd>
        <UncorrectedPriorActsInd>0</UncorrectedPriorActsInd>
        <UndistributedIncomePYInd>0</UndistributedIncomePYInd>
        <BusinessHoldingsInd>0</BusinessHoldingsInd>
        <JeopardyInvestmentsInd>0</JeopardyInvestmentsInd>
        <UncorrectedPYJeopardyInvstInd>0</UncorrectedPYJeopardyInvstInd>
        <InfluenceLegislationInd>0</InfluenceLegislationInd>
        <InfluenceElectionInd>0</InfluenceElectionInd>
        <GrantsToIndividualsInd>0</GrantsToIndividualsInd>
        <GrantsToOrganizationsInd>0</GrantsToOrganizationsInd>
        <NoncharitablePurposeInd>0</NoncharitablePurposeInd>
        <RcvFndsToPayPrsnlBnftCntrctInd>0</RcvFndsToPayPrsnlBnftCntrctInd>
        <PayPremiumsPrsnlBnftCntrctInd>0</PayPremiumsPrsnlBnftCntrctInd>
        <ProhibitedTaxShelterTransInd>0</ProhibitedTaxShelterTransInd>
        <SubjToTaxRmnrtnExPrchtPymtInd>0</SubjToTaxRmnrtnExPrchtPymtInd>
      </StatementsRegardingActy4720Grp>
      <OfficerDirTrstKeyEmplInfoGrp>
        <OfficerDirTrstKeyEmplGrp>
          <PersonNm>EDWIN WELLES</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>DIRECTOR</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>40.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>193479</CompensationAmt>
          <EmployeeBenefitProgramAmt>39739</EmployeeBenefitProgramAmt>
          <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
        </OfficerDirTrstKeyEmplGrp>
        <OfficerDirTrstKeyEmplGrp>
          <PersonNm>WILLEM-JAN RIBBERINK</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>SECRETARY</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>0</CompensationAmt>
          <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
          <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
        </OfficerDirTrstKeyEmplGrp>
        <OfficerDirTrstKeyEmplGrp>
          <PersonNm>MICHEL VAN SWIETAN</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>TREASURER</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>0</CompensationAmt>
          <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
          <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
        </OfficerDirTrstKeyEmplGrp>
        <OfficerDirTrstKeyEmplGrp>
          <PersonNm>SOROOSH SOROOSHIAN</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>DIRECTOR</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>0</CompensationAmt>
          <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
          <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
        </OfficerDirTrstKeyEmplGrp>
        <CompensationHighestPaidEmplGrp>
          <PersonNm>BENJAMIN BALK</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>SCIENTIST V</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>40.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>156027</CompensationAmt>
          <EmployeeBenefitsAmt>35827</EmployeeBenefitsAmt>
          <ExpenseAccountAmt>0</ExpenseAccountAmt>
        </CompensationHighestPaidEmplGrp>
        <CompensationHighestPaidEmplGrp>
          <PersonNm>ARNEJAN VAN LOENEN</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>SCIENTIST V</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>40.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>156027</CompensationAmt>
          <EmployeeBenefitsAmt>34224</EmployeeBenefitsAmt>
          <ExpenseAccountAmt>0</ExpenseAccountAmt>
        </CompensationHighestPaidEmplGrp>
        <CompensationHighestPaidEmplGrp>
          <PersonNm>CORNELIS NEDERHOFF</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>SCIENTIST IV</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>40.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>137271</CompensationAmt>
          <EmployeeBenefitsAmt>16271</EmployeeBenefitsAmt>
          <ExpenseAccountAmt>0</ExpenseAccountAmt>
        </CompensationHighestPaidEmplGrp>
        <CompensationHighestPaidEmplGrp>
          <PersonNm>AMANDA GETZ</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>ADMINISTRATOR II</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>32.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>87992</CompensationAmt>
          <EmployeeBenefitsAmt>7039</EmployeeBenefitsAmt>
          <ExpenseAccountAmt>0</ExpenseAccountAmt>
        </CompensationHighestPaidEmplGrp>
        <CompensationHighestPaidEmplGrp>
          <PersonNm>KEREN BOLTER</PersonNm>
          <USAddress>
            <AddressLine1Txt>8601 GEORGIA AVE 508</AddressLine1Txt>
            <CityNm>SILVER SPRING</CityNm>
            <StateAbbreviationCd>MD</StateAbbreviationCd>
            <ZIPCd>20910</ZIPCd>
          </USAddress>
          <TitleTxt>SCIENTIST IV</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>32.00</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>70521</CompensationAmt>
          <EmployeeBenefitsAmt>22706</EmployeeBenefitsAmt>
          <ExpenseAccountAmt>0</ExpenseAccountAmt>
        </CompensationHighestPaidEmplGrp>
        <OtherEmployeePaidOver50kCnt>1</OtherEmployeePaidOver50kCnt>
        <CompensationOfHghstPdCntrctGrp>
          <BusinessName>
            <BusinessNameLine1Txt>STITCHING DELTARES</BusinessNameLine1Txt>
          </BusinessName>
          <ForeignAddress>
            <AddressLine1Txt>PO BOX 177 2600 MH DELFT</AddressLine1Txt>
            <CityNm>BOUSSINGESQWEQ</CityNm>
            <CountryCd>NL</CountryCd>
          </ForeignAddress>
          <ServiceTypeTxt>RESEARCH/DEVELOPMENT</ServiceTypeTxt>
          <CompensationAmt>4153219</CompensationAmt>
        </CompensationOfHghstPdCntrctGrp>
        <ContractorPaidOver50kCnt>0</ContractorPaidOver50kCnt>
      </OfficerDirTrstKeyEmplInfoGrp>
      <SummaryOfDirectChrtblActyGrp>
        <Description1Txt>1) SUPPORT TO THE US NATIONAL WEATHER SERVICE FOR THEIR FLOOD FORECASTING OPERATIONS CONSISTING OF SYSTEM SUPPORT AND HYDRODYNAMIC MODELING SUPPORT.2) SUPPORT TO THE TENNESSEE VALLEY AUTHORITY FOR THEIR RESERVOIR OPERATIONS AND POWER PLANT OPERATIONS CONSISTING OF HYDRO-THERMAL MODELING TO FORECAST IN STREAM TEMPERATURES, AS WELL AS STREAMFLOW FORECAST SYSTEM SUPPORT.3) COLLABORATIVE RESEARCH WITH THE US GEOLOGICAL SURVEY REGARDING NUMERICAL MODELLING IN RIVERS, ESTUARIES AND COASTAL WATERS INCLUDING SEDIMENT TRANSPORT, AND NUMERICAL METHODS FOR GROUND WATER MODELLING.4) SUPPORT TO THE BONNEVILLE POWER ADMINISTRATION FOR THEIR RESERVOIR OPERATIONS CONSISTING OF BOTH RESERVOIR OPTIMIZATION MODELING AND WATER SUPLY FORECASTING.</Description1Txt>
        <Expenses1Amt>5776811</Expenses1Amt>
      </SummaryOfDirectChrtblActyGrp>
      <SumOfProgramRelatedInvstGrp>
        <TotalAmt>0</TotalAmt>
      </SumOfProgramRelatedInvstGrp>
      <MinimumInvestmentReturnGrp>
        <AverageMonthlyFMVOfSecAmt>0</AverageMonthlyFMVOfSecAmt>
        <AverageMonthlyCashBalancesAmt>1785628</AverageMonthlyCashBalancesAmt>
        <FMVAllOtherNoncharitableAstAmt>0</FMVAllOtherNoncharitableAstAmt>
        <TotalFMVOfUnusedAssetsAmt>1785628</TotalFMVOfUnusedAssetsAmt>
        <ReductionClaimedAmt>0</ReductionClaimedAmt>
        <AcquisitionIndebtednessAmt>0</AcquisitionIndebtednessAmt>
        <AdjustedTotalFMVOfUnusedAstAmt>1785628</AdjustedTotalFMVOfUnusedAstAmt>
        <CashDeemedCharitableAmt>26784</CashDeemedCharitableAmt>
        <NetVlNoncharitableAssetsAmt>1758844</NetVlNoncharitableAssetsAmt>
        <MinimumInvestmentReturnAmt>87942</MinimumInvestmentReturnAmt>
      </MinimumInvestmentReturnGrp>
      <DistributableAmountGrp>
        <Sect4942j3j5FndtnAndFrgnOrgInd>X</Sect4942j3j5FndtnAndFrgnOrgInd>
      </DistributableAmountGrp>
      <PFQualifyingDistributionsGrp>
        <ExpensesAndContributionsAmt>5776811</ExpensesAndContributionsAmt>
        <ProgramRelatedInvstTotalAmt>0</ProgramRelatedInvstTotalAmt>
        <QualifyingDistributionsAmt>5776811</QualifyingDistributionsAmt>
      </PFQualifyingDistributionsGrp>
      <PrivateOperatingFoundationsGrp>
        <PrivateOperatingFndtnRulingDt>2008-09-22</PrivateOperatingFndtnRulingDt>
        <Section4942j3Ind>X</Section4942j3Ind>
        <LessorAdjNetIncmMinInvstRetGrp>
          <CurrentYearAmt>87942</CurrentYearAmt>
          <Year1Amt>80682</Year1Amt>
          <Year2Amt>48598</Year2Amt>
          <Year3Amt>49940</Year3Amt>
          <TotalAmt>267162</TotalAmt>
        </LessorAdjNetIncmMinInvstRetGrp>
        <Pct85LessorAdjIncmOrMinRetGrp>
          <CurrentYearAmt>74751</CurrentYearAmt>
          <Year1Amt>68580</Year1Amt>
          <Year2Amt>41308</Year2Amt>
          <Year3Amt>42449</Year3Amt>
          <TotalAmt>227088</TotalAmt>
        </Pct85LessorAdjIncmOrMinRetGrp>
        <QualifyingDistributionsGrp>
          <CurrentYearAmt>5776811</CurrentYearAmt>
          <Year1Amt>4483830</Year1Amt>
          <Year2Amt>3441568</Year2Amt>
          <Year3Amt>3872489</Year3Amt>
          <TotalAmt>17574698</TotalAmt>
        </QualifyingDistributionsGrp>
        <QualifyingDistriNotUsedDrtGrp>
          <CurrentYearAmt>0</CurrentYearAmt>
          <Year1Amt>0</Year1Amt>
          <Year2Amt>0</Year2Amt>
          <Year3Amt>0</Year3Amt>
          <TotalAmt>0</TotalAmt>
        </QualifyingDistriNotUsedDrtGrp>
        <QualifyingDistriMadeDrtGrp>
          <CurrentYearAmt>5776811</CurrentYearAmt>
          <Year1Amt>4483830</Year1Amt>
          <Year2Amt>3441568</Year2Amt>
          <Year3Amt>3872489</Year3Amt>
          <TotalAmt>17574698</TotalAmt>
        </QualifyingDistriMadeDrtGrp>
        <TotalAssetsGrp>
          <TotalAmt>0</TotalAmt>
        </TotalAssetsGrp>
        <TotalAssetsSect4942j3BiGrp>
          <TotalAmt>0</TotalAmt>
        </TotalAssetsSect4942j3BiGrp>
        <TwoThirdsMinimumInvstRetGrp>
          <TotalAmt>0</TotalAmt>
        </TwoThirdsMinimumInvstRetGrp>
        <TotalSupportGrp>
          <CurrentYearAmt>5738844</CurrentYearAmt>
          <Year1Amt>4807660</Year1Amt>
          <Year2Amt>3983926</Year2Amt>
          <Year3Amt>3847064</Year3Amt>
          <TotalAmt>18377494</TotalAmt>
        </TotalSupportGrp>
        <PublicSupportType>
          <CurrentYearAmt>5738844</CurrentYearAmt>
          <Year1Amt>4807660</Year1Amt>
          <Year2Amt>3983926</Year2Amt>
          <Year3Amt>3847064</Year3Amt>
          <TotalAmt>18377494</TotalAmt>
        </PublicSupportType>
        <LargestSupportFromEOGrp>
          <TotalAmt>0</TotalAmt>
        </LargestSupportFromEOGrp>
        <GrossInvestmentIncomeGrp>
          <TotalAmt>0</TotalAmt>
        </GrossInvestmentIncomeGrp>
      </PrivateOperatingFoundationsGrp>
      <SupplementaryInformationGrp>
        <OnlyContriToPreselectedInd>X</OnlyContriToPreselectedInd>
        <TotalGrantOrContriPdDurYrAmt>0</TotalGrantOrContriPdDurYrAmt>
        <TotalGrantOrContriApprvFutAmt>0</TotalGrantOrContriApprvFutAmt>
      </SupplementaryInformationGrp>
      <AnalysisIncomeProducingActyGrp>
        <ProgramServiceRevenueDtl>
          <Desc>PROGRAM SERVICE REVENUE</Desc>
          <RelatedOrExemptFunctionIncmAmt>5738844</RelatedOrExemptFunctionIncmAmt>
        </ProgramServiceRevenueDtl>
        <IntOnSavAndTempCashInvstGrp>
          <ExclusionCd>14</ExclusionCd>
          <ExclusionAmt>7</ExclusionAmt>
        </IntOnSavAndTempCashInvstGrp>
        <SubtotalsIncmProducingActyGrp>
          <UnrelatedBusinessTaxblIncmAmt>0</UnrelatedBusinessTaxblIncmAmt>
          <ExclusionAmt>7</ExclusionAmt>
          <RelatedOrExemptFunctionIncmAmt>5738844</RelatedOrExemptFunctionIncmAmt>
        </SubtotalsIncmProducingActyGrp>
        <TotalIncomeProducingActyAmt>5738851</TotalIncomeProducingActyAmt>
      </AnalysisIncomeProducingActyGrp>
      <RlnOfActyToAccomOfExmptPrpsGrp>
        <RlnOfActyToAccomOfExmptPrpsGrp>
          <LineNumberTxt>1</LineNumberTxt>
          <RelationshipStatementTxt>OUR CONTRACTS WITH FEDERAL AND STATE AGENCIES OFFERS THE OPPORTUNITY</RelationshipStatementTxt>
        </RlnOfActyToAccomOfExmptPrpsGrp>
        <RlnOfActyToAccomOfExmptPrpsGrp>
          <LineNumberTxt>1</LineNumberTxt>
          <RelationshipStatementTxt>TO EXTEND EXISTING METHODOLOGIES, TO DISSEMINATE KNOWLEDGE TO OTHERS,</RelationshipStatementTxt>
        </RlnOfActyToAccomOfExmptPrpsGrp>
        <RlnOfActyToAccomOfExmptPrpsGrp>
          <LineNumberTxt>1</LineNumberTxt>
          <RelationshipStatementTxt>TO DEFINE NEW ISSUES WHICH REQUIRE NEW RESEARCH.</RelationshipStatementTxt>
        </RlnOfActyToAccomOfExmptPrpsGrp>
      </RlnOfActyToAccomOfExmptPrpsGrp>
      <TrnsfrTransRlnNonchrtblEOGrp>
        <TrnsfrOfCashToNonchrtblEOInd>0</TrnsfrOfCashToNonchrtblEOInd>
        <TrnsfrOtherAssetNonchrtblEOInd>0</TrnsfrOtherAssetNonchrtblEOInd>
        <SalesOrExchangesOfAssetsInd>0</SalesOrExchangesOfAssetsInd>
        <PurchaseOfAssetsNonchrtblEOInd>0</PurchaseOfAssetsNonchrtblEOInd>
        <RentalOfFacilitiesOthAssetsInd>0</RentalOfFacilitiesOthAssetsInd>
        <ReimbursementArrangementsInd>0</ReimbursementArrangementsInd>
        <LoansOrLoanGuaranteesInd>0</LoansOrLoanGuaranteesInd>
        <PerformanceOfServicesEtcInd>0</PerformanceOfServicesEtcInd>
        <SharingOfFacilitiesEtcInd>0</SharingOfFacilitiesEtcInd>
        <RelationshipsNonchrtblEOInd>0</RelationshipsNonchrtblEOInd>
      </TrnsfrTransRlnNonchrtblEOGrp>
    </IRS990PF>
    <AccountingFeesSchedule documentId="RetDoc2002200001">
      <AccountingFeesDetail>
        <CategoryTxt>ACCOUNTING</CategoryTxt>
        <Amt>69475</Amt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>38581</DisbursementsCharitablePrpsAmt>
      </AccountingFeesDetail>
    </AccountingFeesSchedule>
    <LegalFeesSchedule documentId="RetDoc2002100001">
      <LegalFeesGrp>
        <CategoryTxt>LEGAL FEES</CategoryTxt>
        <LegalFeesAmt>48868</LegalFeesAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>48036</DisbursementsCharitablePrpsAmt>
      </LegalFeesGrp>
    </LegalFeesSchedule>
    <OtherAssetsSchedule documentId="RetDoc2046600001">
      <OtherAssetsScheduleGrp>
        <Desc>SECURITY DEPOSITS</Desc>
        <BOYBookValueAmt>1458</BOYBookValueAmt>
        <EOYBookValueAmt>1458</EOYBookValueAmt>
        <EOYFMVAmt>1458</EOYFMVAmt>
      </OtherAssetsScheduleGrp>
    </OtherAssetsSchedule>
    <OtherExpensesSchedule documentId="RetDoc2003200001">
      <OtherExpensesScheduleGrp>
        <Desc>INSURANCE</Desc>
        <RevenueAndExpensesPerBooksAmt>86844</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>81237</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
      <OtherExpensesScheduleGrp>
        <Desc>POSTAGE AND DELIVERY</Desc>
        <RevenueAndExpensesPerBooksAmt>489</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>489</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
      <OtherExpensesScheduleGrp>
        <Desc>SUPPLIES</Desc>
        <RevenueAndExpensesPerBooksAmt>3115</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>2607</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
      <OtherExpensesScheduleGrp>
        <Desc>DUES, FEES AND LICENSES</Desc>
        <RevenueAndExpensesPerBooksAmt>34538</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>36271</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
      <OtherExpensesScheduleGrp>
        <Desc>DATA PROCESSING</Desc>
        <RevenueAndExpensesPerBooksAmt>23408</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>23087</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
      <OtherExpensesScheduleGrp>
        <Desc>OTHER EXPENSES</Desc>
        <RevenueAndExpensesPerBooksAmt>49978</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>49978</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
      <OtherExpensesScheduleGrp>
        <Desc>CURRENCY LOSS</Desc>
        <RevenueAndExpensesPerBooksAmt>6543</RevenueAndExpensesPerBooksAmt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>6543</DisbursementsCharitablePrpsAmt>
      </OtherExpensesScheduleGrp>
    </OtherExpensesSchedule>
    <OtherIncomeSchedule2 documentId="RetDoc2001500001">
      <OtherIncomeDetail>
        <Desc>PROGRAM SERVICE REVENUE</Desc>
        <RevenueAndExpensesPerBooksAmt>5738844</RevenueAndExpensesPerBooksAmt>
        <AdjustedNetIncomeAmt>5738844</AdjustedNetIncomeAmt>
      </OtherIncomeDetail>
    </OtherIncomeSchedule2>
    <OtherProfessionalFeesSchedule documentId="RetDoc2002300001">
      <OtherProfessionalFeesDetail>
        <CategoryTxt>SUBCONTRACTS</CategoryTxt>
        <Amt>4222455</Amt>
        <NetInvestmentIncomeAmt>0</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
        <DisbursementsCharitablePrpsAmt>4332898</DisbursementsCharitablePrpsAmt>
      </OtherProfessionalFeesDetail>
    </OtherProfessionalFeesSchedule>
  </ReturnData>
</Return>
