<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema version="5.0"
            xmlns:nwis="http://water.usgs.gov/XML/NWIS/5.0" 
            xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
            elementFormDefault="qualified">

  <xsd:include schemaLocation="Equipment.xsd"/>
  <xsd:include schemaLocation="MonitorSensorLocation.xsd"/>

  <xsd:element name="EquipmentChange">
    <xsd:annotation>
      <xsd:documentation>
        <Definition>Change (removal, replacement, or addition) to site equipment or site equipment sensors</Definition>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:choice>
          <xsd:element name="EquipmentRemoval">
            <xsd:annotation>
              <xsd:documentation>
                <Definition>Equipment item at a site has been removed</Definition>
              </xsd:documentation>
            </xsd:annotation>
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="ExistingEquipment" type="EquipmentType">
                  <xsd:annotation>
                    <xsd:documentation>
                      <Definition>The equipment item that has been removed from the site</Definition>
                    </xsd:documentation>
                  </xsd:annotation>
                </xsd:element>
              </xsd:sequence>
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="EquipmentAddition">
            <xsd:annotation>
              <xsd:documentation>
                <Definition>Equipment item at a site that has been installed</Definition>
              </xsd:documentation>
            </xsd:annotation>
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element ref="Location">
                  <xsd:annotation>
                    <xsd:documentation>
                      <Definition>The location at a site where the equipment is installed.</Definition>
                    </xsd:documentation>
                  </xsd:annotation>
                </xsd:element>
                <xsd:element name="Equipment" type="EquipmentType">
                  <xsd:annotation>
                    <xsd:documentation>
                      <Definition>The equipment item has been installed at the site</Definition>
                    </xsd:documentation>
                  </xsd:annotation>
                </xsd:element>
                <xsd:element name="MonitorSensorLocation" type="MonitorSensorLocation" minOccurs="0" maxOccurs="unbounded"/>
              </xsd:sequence>
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="EquipmentReplacement">
            <xsd:annotation>
              <xsd:documentation>
                <Definition>The equipment item has been replaced at the site</Definition>
              </xsd:documentation>
            </xsd:annotation>
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="ExistingEquipment" type="EquipmentType">
                  <xsd:annotation>
                    <xsd:documentation>
                      <Definition>The equipment item that has been changed for the site</Definition>
                    </xsd:documentation>
                  </xsd:annotation>
                </xsd:element>
                <xsd:element name="Equipment" type="EquipmentType">
                  <xsd:annotation>
                    <xsd:documentation>
                      <Definition>The equipment item that has replaced the existing equipment item from the site</Definition>
                    </xsd:documentation>
                  </xsd:annotation>
                </xsd:element>
                <xsd:element name="MonitorSensorLocation" type="MonitorSensorLocation" minOccurs="0" maxOccurs="unbounded"/>
              </xsd:sequence>
            </xsd:complexType>
          </xsd:element>
        </xsd:choice>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>
